login function added, include library Jsoup

app/build.gradle

@@ -22,6 +22,9 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.android.support:appcompat-v7:26.1.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.0'
+    implementation 'com.android.support:design:26.1.0'
+    // jsoup HTML parser library @ https://jsoup.org/
+    compile 'org.jsoup:jsoup:1.11.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

app/src/main/AndroidManifest.xml

@@ -2,6 +2,11 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="tech.goda.studyck">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
@@ -16,6 +21,9 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <activity
+            android:name=".LoginActivity"
+            android:label="@string/title_activity_login"></activity>
     </application>
 
 </manifest>

app/src/main/java/tech/goda/studyck/KeyStoreHelper.java

@@ -0,0 +1,219 @@
+package tech.goda.studyck;
+
+import android.content.Context;
+import android.os.Build;
+import android.security.KeyPairGeneratorSpec;
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyProperties;
+import android.support.annotation.RequiresApi;
+import android.util.Base64;
+import android.util.Log;
+
+import java.math.BigInteger;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.KeyPairGenerator;
+import java.security.KeyStore;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.SecureRandom;
+import java.util.Calendar;
+
+import javax.crypto.Cipher;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+import javax.security.auth.x500.X500Principal;
+
+/**
+ * Created by Jerry on 2018/7/8.
+ */
+
+public class KeyStoreHelper {
+    private static final String TAG = "KEYSTORE";
+
+    private static final String KEYSTORE_PROVIDER = "AndroidKeyStore";
+    private static final String AES_MODE = "AES/GCM/NoPadding";
+    private static final String RSA_MODE = "RSA/ECB/PKCS1Padding";
+
+    private static final String KEYSTORE_ALIAS = "KEYSTORE_DEMO";
+
+
+    private KeyStore keyStore;
+    private SharedPreferencesHelper prefsHelper;
+
+    public KeyStoreHelper(Context context, SharedPreferencesHelper sharedPreferencesHelper) {
+        try {
+            prefsHelper = sharedPreferencesHelper;
+            keyStore = KeyStore.getInstance(KEYSTORE_PROVIDER);
+            keyStore.load(null);
+
+            if (!keyStore.containsAlias(KEYSTORE_ALIAS)) {
+                prefsHelper.setIV("");
+                genKeyStoreKey(context);
+                genAESKey();
+            }
+
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+    }
+
+
+    private void genKeyStoreKey(Context context) throws Exception {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            generateRSAKey_AboveApi23();
+        } else {
+            generateRSAKey_BelowApi23(context);
+        }
+    }
+
+
+
+    @RequiresApi(api = Build.VERSION_CODES.M)
+    private void generateRSAKey_AboveApi23() throws Exception {
+        KeyPairGenerator keyPairGenerator = KeyPairGenerator
+                .getInstance(KeyProperties.KEY_ALGORITHM_RSA, KEYSTORE_PROVIDER);
+
+
+        KeyGenParameterSpec keyGenParameterSpec = new KeyGenParameterSpec
+                .Builder(KEYSTORE_ALIAS, KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
+                .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA512)
+                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1)
+                .build();
+
+        keyPairGenerator.initialize(keyGenParameterSpec);
+        keyPairGenerator.generateKeyPair();
+
+    }
+
+    private void generateRSAKey_BelowApi23(Context context) throws NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
+        Calendar start = Calendar.getInstance();
+        Calendar end = Calendar.getInstance();
+        end.add(Calendar.YEAR, 30);
+
+        KeyPairGeneratorSpec spec = new KeyPairGeneratorSpec.Builder(context)
+                .setAlias(KEYSTORE_ALIAS)
+                .setSubject(new X500Principal("CN=" + KEYSTORE_ALIAS))
+                .setSerialNumber(BigInteger.TEN)
+                .setStartDate(start.getTime())
+                .setEndDate(end.getTime())
+                .build();
+
+        KeyPairGenerator keyPairGenerator = KeyPairGenerator
+                .getInstance(KeyProperties.KEY_ALGORITHM_RSA, KEYSTORE_PROVIDER);
+
+        keyPairGenerator.initialize(spec);
+        keyPairGenerator.generateKeyPair();
+    }
+
+    public String encrypt(String plainText) {
+        try {
+            return encryptAES(plainText);
+
+        } catch (Exception e) {
+            Log.d(TAG, Log.getStackTraceString(e));
+            return "";
+        }
+    }
+    public String decrypt(String encryptedText) {
+        try {
+            return decryptAES(encryptedText);
+
+        } catch (Exception e) {
+            Log.d(TAG, Log.getStackTraceString(e));
+            return "";
+        }
+
+    }
+
+
+    private String encryptRSA(byte[] plainText) throws Exception {
+        PublicKey publicKey = keyStore.getCertificate(KEYSTORE_ALIAS).getPublicKey();
+
+        Cipher cipher = Cipher.getInstance(RSA_MODE);
+        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
+
+        byte[] encryptedByte = cipher.doFinal(plainText);
+        return Base64.encodeToString(encryptedByte, Base64.DEFAULT);
+    }
+
+
+    private byte[] decryptRSA(String encryptedText) throws Exception {
+        PrivateKey privateKey = (PrivateKey) keyStore.getKey(KEYSTORE_ALIAS, null);
+
+        Cipher cipher = Cipher.getInstance(RSA_MODE);
+        cipher.init(Cipher.DECRYPT_MODE, privateKey);
+
+        byte[] encryptedBytes = Base64.decode(encryptedText, Base64.DEFAULT);
+        byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
+
+        return decryptedBytes;
+    }
+
+    private void genAESKey() throws Exception {
+        // Generate AES-Key
+        byte[] aesKey = new byte[16];
+        SecureRandom secureRandom = new SecureRandom();
+        secureRandom.nextBytes(aesKey);
+
+
+        // Generate 12 bytes iv then save to SharedPrefs
+        byte[] generated = secureRandom.generateSeed(12);
+        String iv = Base64.encodeToString(generated, Base64.DEFAULT);
+        prefsHelper.setIV(iv);
+
+
+        // Encrypt AES-Key with RSA Public Key then save to SharedPrefs
+        String encryptAESKey = encryptRSA(aesKey);
+        prefsHelper.setAESKey(encryptAESKey);
+    }
+
+
+    /**
+     * AES Encryption
+     * @param plainText: A string which needs to be encrypted.
+     * @return A base64's string after encrypting.
+     */
+    private String encryptAES(String plainText) throws Exception {
+        Cipher cipher = Cipher.getInstance(AES_MODE);
+        cipher.init(Cipher.ENCRYPT_MODE, getAESKey(), new IvParameterSpec(getIV()));
+
+        // 加密過後的byte
+        byte[] encryptedBytes = cipher.doFinal(plainText.getBytes());
+
+        // 將byte轉為base64的string編碼
+        return Base64.encodeToString(encryptedBytes, Base64.DEFAULT);
+    }
+
+
+    private String decryptAES(String encryptedText) throws Exception {
+        // 將加密過後的Base64編碼格式 解碼成 byte
+        byte[] decodedBytes = Base64.decode(encryptedText.getBytes(), Base64.DEFAULT);
+
+        // 將解碼過後的byte 使用AES解密
+        Cipher cipher = Cipher.getInstance(AES_MODE);
+        cipher.init(Cipher.DECRYPT_MODE, getAESKey(), new IvParameterSpec(getIV()));
+
+        return new String(cipher.doFinal(decodedBytes));
+    }
+
+
+    private byte[] getIV() {
+        String prefIV = prefsHelper.getIV();
+        return Base64.decode(prefIV, Base64.DEFAULT);
+    }
+
+
+
+    private SecretKeySpec getAESKey() throws Exception {
+        String encryptedKey = prefsHelper.getAESKey();
+        byte[] aesKey = decryptRSA(encryptedKey);
+
+        return new SecretKeySpec(aesKey, AES_MODE);
+    }
+
+
+
+}

app/src/main/java/tech/goda/studyck/LoginActivity.java

@@ -0,0 +1,314 @@
+package tech.goda.studyck;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.annotation.TargetApi;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.support.annotation.NonNull;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.AppCompatActivity;
+import android.app.LoaderManager.LoaderCallbacks;
+
+import android.content.CursorLoader;
+import android.content.Loader;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.AsyncTask;
+
+import android.os.Build;
+import android.os.Bundle;
+import android.provider.ContactsContract;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.KeyEvent;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.inputmethod.EditorInfo;
+import android.widget.ArrayAdapter;
+import android.widget.AutoCompleteTextView;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static android.Manifest.permission.READ_CONTACTS;
+import static tech.goda.studyck.Network.LOGIN_URI;
+
+/**
+ * A login screen that offers login via email/password.
+ */
+public class LoginActivity extends AppCompatActivity  {
+
+    /**
+     * Id to identity READ_CONTACTS permission request.
+     */
+    private static final int REQUEST_READ_CONTACTS = 0;
+
+    /**
+     * A dummy authentication store containing known user names and passwords.
+     * TODO: remove after connecting to a real authentication system.
+     */
+    private static final String[] DUMMY_CREDENTIALS = new String[]{
+            "foo@example.com:hello", "bar@example.com:world"
+    };
+    /**
+     * Keep track of the login task to ensure we can cancel it if requested.
+     */
+    private UserLoginTask mAuthTask = null;
+
+    // UI references.
+    private AutoCompleteTextView mEmailView;
+    private EditText mPasswordView;
+    private View mProgressView;
+    private View mLoginFormView;
+    private String response = null;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_login);
+        // Set up the login form.
+
+
+
+
+        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
+
+        mPasswordView = (EditText) findViewById(R.id.password);
+        mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
+            @Override
+            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
+                if (id == EditorInfo.IME_ACTION_DONE || id == EditorInfo.IME_NULL) {
+                    attemptLogin();
+                    return true;
+                }
+                return false;
+            }
+        });
+
+        Intent intent = this.getIntent();
+
+        try{
+            mEmailView.setText(intent.getExtras().getString("account"));
+            mPasswordView.setText(intent.getExtras().getString("password"));
+        } catch(NullPointerException e){
+            Log.e("Login", Log.getStackTraceString(e));
+        }
+
+        Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
+        mEmailSignInButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                attemptLogin();
+            }
+        });
+
+        mLoginFormView = findViewById(R.id.login_form);
+        mProgressView = findViewById(R.id.login_progress);
+    }
+
+    private boolean mayRequestContacts() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            return true;
+        }
+        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
+            return true;
+        }
+        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
+            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(android.R.string.ok, new View.OnClickListener() {
+                        @Override
+                        @TargetApi(Build.VERSION_CODES.M)
+                        public void onClick(View v) {
+                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+                        }
+                    });
+        } else {
+            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+        }
+        return false;
+    }
+
+    /**
+     * Callback received when a permissions request has been completed.
+     */
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
+                                           @NonNull int[] grantResults) {
+        if (requestCode == REQUEST_READ_CONTACTS) {
+            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+
+            }
+        }
+    }
+
+
+    /**
+     * Attempts to sign in or register the account specified by the login form.
+     * If there are form errors (invalid email, missing fields, etc.), the
+     * errors are presented and no actual login attempt is made.
+     */
+    private void attemptLogin() {
+        if (mAuthTask != null) {
+            return;
+        }
+
+        // Reset errors.
+        mEmailView.setError(null);
+        mPasswordView.setError(null);
+
+        // Store values at the time of the login attempt.
+        String email = mEmailView.getText().toString();
+        String password = mPasswordView.getText().toString();
+
+        boolean cancel = false;
+        View focusView = null;
+
+        // Check for a valid password, if the user entered one.
+        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
+            mPasswordView.setError(getString(R.string.error_invalid_password));
+            focusView = mPasswordView;
+            cancel = true;
+        }
+
+        // Check for a valid email address.
+        if (TextUtils.isEmpty(email)) {
+            mEmailView.setError(getString(R.string.error_field_required));
+            focusView = mEmailView;
+            cancel = true;
+        } else if (!isEmailValid(email)) {
+            mEmailView.setError(getString(R.string.error_invalid_email));
+            focusView = mEmailView;
+            cancel = true;
+        }
+
+        if (cancel) {
+            // There was an error; don't attempt login and focus the first
+            // form field with an error.
+            focusView.requestFocus();
+        } else {
+            // Show a progress spinner, and kick off a background task to
+            // perform the user login attempt.
+            showProgress(true);
+            mAuthTask = new UserLoginTask(email, password);
+            mAuthTask.execute((Void) null);
+        }
+    }
+
+    private boolean isEmailValid(String email) {
+        //TODO: Replace this with your own logic
+        return true;
+    }
+
+    private boolean isPasswordValid(String password) {
+        //TODO: Replace this with your own logic
+        return true;
+    }
+
+    /**
+     * Shows the progress UI and hides the login form.
+     */
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
+    private void showProgress(final boolean show) {
+        // On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
+        // for very easy animations. If available, use these APIs to fade-in
+        // the progress spinner.
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
+            int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);
+
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+            mLoginFormView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+                }
+            });
+
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mProgressView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+                }
+            });
+        } else {
+            // The ViewPropertyAnimator APIs are not available, so simply show
+            // and hide the relevant UI components.
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+        }
+    }
+
+
+    /**
+     * Represents an asynchronous login/registration task used to authenticate
+     * the user.
+     */
+    public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
+
+        private final String mEmail;
+        private final String mPassword;
+
+        UserLoginTask(String email, String password) {
+            mEmail = email;
+            mPassword = password;
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            // TODO: attempt authentication against a network service.
+
+                // Simulate network access.
+            Map<String, String> param = new HashMap<>();
+            param.put("f_uid", mEmail);
+            param.put("f_pwd", mPassword);
+            response = Network.requestPost(LOGIN_URI, param);
+            //Thread.sleep(2000);
+            Log.e("Login", response);
+            return !response.contains("錯誤");
+
+        }
+
+        @Override
+        protected void onPostExecute(final Boolean success) {
+            mAuthTask = null;
+            showProgress(false);
+
+            if (success) {
+                Intent intent = new Intent();
+                intent.putExtra("response", response);
+                intent.putExtra("account", mEmail);
+                intent.putExtra("password", mPassword);
+                setResult(RESULT_OK, intent);
+                finish();
+            } else {
+                mPasswordView.setError(getString(R.string.error_incorrect_password));
+                mPasswordView.requestFocus();
+            }
+        }
+
+        @Override
+        protected void onCancelled() {
+            mAuthTask = null;
+            showProgress(false);
+        }
+    }
+
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        if ((keyCode == KeyEvent.KEYCODE_BACK)) {
+            //Toast.makeText(getApplicationContext(), "請登入SAD", Toast.LENGTH_SHORT).show();
+            finishAffinity();
+        }
+        return super.onKeyDown(keyCode, event);
+
+    }
+}
+

app/src/main/java/tech/goda/studyck/MainActivity.java

@@ -1,13 +1,305 @@
 package tech.goda.studyck;
 
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.app.Activity;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+import android.provider.DocumentsContract;
+import android.support.annotation.NonNull;
+import android.support.v4.provider.DocumentFile;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.text.Html;
+import android.text.Layout;
+import android.util.Log;
+import android.view.View;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.select.Elements;
+
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.CookieHandler;
+import java.net.CookieManager;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.security.KeyStore;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
 
 public class MainActivity extends AppCompatActivity {
 
+    private static final int PICK_FILE_REQUEST = 0;
+    private static final int LOGIN = 1;
+    TextView messageText;
+    Button uploadButton, choose;
+    EditText editFileName;
+    int serverResponseCode = 0;
+
+    String uploadServerUri = null;
+    InputStream in;
+    String fileName;
+    String loginResponse;
+    /**********  File Path *************/
+    String uploadFilePath = Environment.getExternalStorageDirectory().getPath() + "/test.png";
+    Button button3;
+
+    KeyStoreHelper keyStoreHelper;
+    SharedPreferencesHelper preferencesHelper;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+        Log.e("Directory", uploadFilePath);
+        uploadButton = findViewById(R.id.uploadButton);
+        choose = findViewById(R.id.choose);
+        messageText  = findViewById(R.id.messageText);
+        editFileName = findViewById(R.id.fileName);
+        button3 = findViewById(R.id.button3);
+
+        CookieManager manager = new CookieManager();
+        CookieHandler.setDefault(manager);
+
+        preferencesHelper = new SharedPreferencesHelper(getApplicationContext());
+        keyStoreHelper = new KeyStoreHelper(getApplicationContext(), preferencesHelper);
+
+        messageText.setText("Uploading file path : " + uploadFilePath);
+
+
+        //uploadServerUri = "http://study.ck.tp.edu.tw/login_chk.asp";
+        uploadServerUri = "http://192.168.173.104/WebPageTest/upload-big5.php";
+
+        uploadButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+
+
+                new Thread(new Runnable() {
+                    public void run() {
+                        runOnUiThread(new Runnable() {
+                            public void run() {
+                                messageText.setText("uploading started.....");
+                            }
+                        });
+
+                        Network.uploadFile(uploadServerUri, in, editFileName.getText().toString());
+
+                    }
+                }).start();
+            }
+        });
+
+        button3.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                final Map<String, String> params = new HashMap<>();
+                
+                params.put("f_mnuid", "");
+
+                new Thread(new Runnable() {
+                    public void run() {
+                        Network.requestPost("http://study.ck.tp.edu.tw", params);
+                    }
+                }).start();
+            }
+        });
+
+        choose.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                showFileChooser();
+            }
+        });
+
+        String encryptedText = preferencesHelper.getInput();
+        final String mEmail = preferencesHelper.getString(SharedPreferencesHelper.PREF_AC);
+        final String mPassword = keyStoreHelper.decrypt(encryptedText);
+        if(mEmail.equals("") || mPassword.equals("")){
+            callLogin(mEmail, mPassword);
+        }
+        else{
+            final Map<String, String> param = new HashMap<>();
+            param.put("f_uid", mEmail);
+            param.put("f_pwd", mPassword);
+            Toast.makeText(getApplicationContext(), "自動登入中...", Toast.LENGTH_SHORT).show();
+
+            View layout = findViewById(android.R.id.content);
+            layout.setVisibility(View.GONE);
+
+            new Thread(new Runnable() {
+                public void run() {
+                    loginResponse = Network.requestPost(Network.LOGIN_URI, param);
+                    //Thread.sleep(2000);
+                    Log.e("Login", loginResponse);
+
+                    runOnUiThread(new Runnable() {
+                        @Override
+                        public void run() {
+                            if(!loginResponse.contains("錯誤")){
+                                LoginSuccess(mEmail, mPassword);
+                            }
+                            else{
+                                Toast.makeText(getApplicationContext(), "Login Failed", Toast.LENGTH_SHORT).show();
+                                callLogin(mEmail, mPassword);
+                            }
+                        }
+                    });
+                }
+            }).start();
+
+
+            //return !response.contains("錯誤");
+        }
+
     }
+
+    private void callLogin(String account, String password) {
+        Intent intent = new Intent(MainActivity.this, LoginActivity.class);
+        intent.putExtra("account", account);
+        intent.putExtra("password", password);
+        startActivityForResult(intent, LOGIN);
+    }
+
+
+    private void LoginSuccess(String account, String password) {
+        View layout = findViewById(android.R.id.content);
+        Toast.makeText(getApplicationContext(), "登入成功！！", Toast.LENGTH_SHORT).show();
+        Document doc = Jsoup.parse(loginResponse);
+        String name =  doc.select("form > font").first().text();
+        messageText.setText(name);
+
+        // Save Login Information
+        String encryptedPassword = keyStoreHelper.encrypt(password);
+        preferencesHelper.setInput(encryptedPassword);
+        preferencesHelper.putString(SharedPreferencesHelper.PREF_AC, account);
+
+        layout.setVisibility(View.VISIBLE);
+
+    }
+
+    private void showFileChooser() {
+        Intent intent = new Intent();
+        //sets the select file to all types of files
+        intent.setType("*/*");
+        //allows to select data and return it
+        intent.setAction(Intent.ACTION_GET_CONTENT);
+        //starts new activity to select file and return data
+        startActivityForResult(Intent.createChooser(intent,"Choose File to Upload.."), PICK_FILE_REQUEST);
+    }
+
+    private boolean isVirtualFile(Uri uri) {
+        if (!DocumentsContract.isDocumentUri(this, uri)) {
+            return false;
+        }
+
+        Cursor cursor = getContentResolver().query(
+                uri,
+                new String[] { DocumentsContract.Document.COLUMN_FLAGS },
+                null, null, null);
+
+        int flags = 0;
+        if (cursor.moveToFirst()) {
+            flags = cursor.getInt(0);
+        }
+        cursor.close();
+
+        return (flags & DocumentsContract.Document.FLAG_VIRTUAL_DOCUMENT) != 0;
+    }
+
+    private InputStream getInputStreamForVirtualFile(Uri uri, String mimeTypeFilter)
+            throws IOException {
+
+        ContentResolver resolver = getContentResolver();
+
+        String[] openableMimeTypes = resolver.getStreamTypes(uri, mimeTypeFilter);
+
+        if (openableMimeTypes == null ||
+                openableMimeTypes.length < 1) {
+            throw new FileNotFoundException();
+        }
+
+        return resolver
+                .openTypedAssetFileDescriptor(uri, openableMimeTypes[0], null)
+                .createInputStream();
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+
+        switch (requestCode){
+            case PICK_FILE_REQUEST:
+                if(resultCode == RESULT_OK) {
+                    if (data == null) {
+                        //no data present
+                        return;
+                    }
+
+
+                    Uri selectedFileUri = data.getData();
+                    fileName = DocumentFile.fromSingleUri(this, selectedFileUri).getName();
+                    editFileName.setText(fileName);
+                    messageText.setText("Upload File:" + fileName + "(Change file name below)");
+                    Log.e("GetPathDocumentName", fileName);
+
+                    try {
+                        if (isVirtualFile(selectedFileUri)) {
+                            Log.e("GetPath", "This is virtual file");
+                            in = getInputStreamForVirtualFile(selectedFileUri, "*/*");
+
+                        } else {
+                            in = getContentResolver().openInputStream(selectedFileUri);
+                        }
+
+
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                        Log.e("GetPathError", e.toString());
+                    }
+                }
+            /*if(uploadFilePath != null && !uploadFilePath.equals("")){
+                messageText.setText(uploadFilePath);
+            }else{
+                Toast.makeText(this,"Cannot upload file to server",Toast.LENGTH_SHORT).show();
+            }*/
+                break;
+            case LOGIN:
+                if(resultCode == RESULT_OK){
+                    Bundle bundle =  data.getExtras();
+                    String account = bundle.getString("account");
+                    String password = bundle.getString("password");
+                    loginResponse = bundle.getString("response");
+                    //messageText.setText(loginResponse);
+                    LoginSuccess(account, password);
+                }
+                break;
+        }
+
+
+    }
+
+
+
 }

app/src/main/java/tech/goda/studyck/Network.java

@@ -0,0 +1,381 @@
+package tech.goda.studyck;
+
+import android.app.Activity;
+import android.content.ContentResolver;
+import android.content.Intent;
+import android.database.Cursor;
+import android.net.Uri;
+import android.provider.DocumentsContract;
+import android.support.v4.provider.DocumentFile;
+import android.util.Log;
+import android.widget.Toast;
+
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Created by Jerry on 2018/7/7.
+ */
+
+public class Network {
+    public static final String LOGIN_URI = "http://study.ck.tp.edu.tw/login_chk.asp";
+
+    public static String uploadFile(String sourceFileUri, InputStream in, String uploadFileName) {
+
+
+        //String fileName = sourceFileUri;
+        HttpURLConnection conn = null;
+        //CookieManager cookieManager = null;
+        DataOutputStream dos = null;
+        String lineEnd = "\r\n";
+        String twoHyphens = "--";
+        String boundary = "*****";
+        int bytesRead, bytesAvailable, bufferSize;
+        byte[] buffer;
+        int maxBufferSize = 1 * 1024 * 1024;
+
+        //File sourceFile = new File(sourceFileUri);
+        String response = null;
+        if(in == null){
+            /*runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    Toast.makeText(MainActivity.this, "Please Choose File First.", Toast.LENGTH_SHORT).show();
+                }
+            });*/
+            return null;
+        }
+        else{
+            try {
+
+                // open a URL connection to the Servlet
+                //FileInputStream fileInputStream = new FileInputStream(sourceFile);
+                URL url = new URL(sourceFileUri);
+
+                // Open a HTTP  connection to  the URL
+                conn = (HttpURLConnection) url.openConnection();
+                conn.setDoInput(true); // Allow Inputs
+                conn.setDoOutput(true); // Allow Outputs
+                conn.setUseCaches(false); // Don't use a Cached Copy
+                conn.setRequestMethod("POST");
+                conn.setRequestProperty("Connection", "Keep-Alive");
+                
+                conn.setRequestProperty("ENCTYPE", "multipart/form-data");
+                conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
+                conn.setRequestProperty("f_file", uploadFileName);
+
+                dos = new DataOutputStream(conn.getOutputStream());
+
+                dos.writeBytes(twoHyphens + boundary + lineEnd);
+                dos.writeBytes("Content-Disposition: form-data; name=\"f_hwintro\""+ lineEnd + lineEnd);
+                dos.writeBytes("" + lineEnd);
+                dos.writeBytes(twoHyphens + boundary + lineEnd);
+                dos.writeBytes("Content-Disposition: form-data; name=\"f_file\";filename=\"");
+                dos.write(uploadFileName.getBytes());
+                dos.writeBytes("\"" + lineEnd);
+
+                dos.writeBytes(lineEnd);
+
+                // create a buffer of  maximum size
+                bytesAvailable = in.available();
+
+                bufferSize = Math.min(bytesAvailable, maxBufferSize);
+                buffer = new byte[bufferSize];
+
+                // read file and write it into form...
+                bytesRead = in.read(buffer, 0, bufferSize);
+                while (bytesRead > 0) {
+
+                    dos.write(buffer, 0, bufferSize);
+                    bytesAvailable = in.available();
+                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
+                    bytesRead = in.read(buffer, 0, bufferSize);
+
+                }
+
+                // send multipart form data necessary after file data...
+                dos.writeBytes(lineEnd);
+                dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
+
+                // Responses from the server (code and message)
+                int serverResponseCode = conn.getResponseCode();
+                String serverResponseMessage = conn.getResponseMessage();
+                try{
+                    BufferedReader br;
+                    if (200 <= serverResponseCode && serverResponseCode <= 299) {
+                        br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "big5"));
+                    } else {
+                        br = new BufferedReader(new InputStreamReader(conn.getErrorStream(), "big5"));
+                    }
+                    StringBuilder sb = new StringBuilder();
+                    String output;
+                    while ((output = br.readLine()) != null) {
+                        sb.append(output);
+                    }
+
+                    response = sb.toString();
+                    Log.e("Response", response);
+                } catch(java.io.IOException e){
+                    e.printStackTrace();
+                }
+                Log.e("uploadFile", "HTTP Response is : "
+                        + serverResponseMessage + ": " + serverResponseCode);
+
+                if(serverResponseCode == 200){
+
+                    /*runOnUiThread(new Runnable() {
+                        public void run() {
+
+                            String msg = "File Upload Completed.";
+
+                            messageText.setText(msg);
+                            //Toast.makeText(MainActivity.this, "File Upload Completed.",
+                            //Toast.LENGTH_SHORT).show();
+                        }
+                    });*/
+                }
+
+                //close the streams //
+                in.close();
+                dos.flush();
+                dos.close();
+
+            } catch (MalformedURLException e) {
+
+                e.printStackTrace();
+                Log.e("Upload file to server", "error: " + e.getMessage(), e);
+            } catch (Exception e) {
+                e.printStackTrace();
+                Log.e("Upload", "Exception : "
+                        + e.getMessage(), e);
+            }
+            return response;
+        }
+            /*if (!sourceFile.isFile()) {
+
+                Log.e("uploadFile", "Source File not exist :"
+                        +uploadFilePath);
+
+                return 0;
+
+            }
+
+            else
+            {
+                try {
+
+                    // open a URL connection to the Servlet
+                    FileInputStream fileInputStream = new FileInputStream(sourceFile);
+                    URL url = new URL(uploadServerUri);
+
+                    // Open a HTTP  connection to  the URL
+                    conn = (HttpURLConnection) url.openConnection();
+                    conn.setDoInput(true); // Allow Inputs
+                    conn.setDoOutput(true); // Allow Outputs
+                    conn.setUseCaches(false); // Don't use a Cached Copy
+                    conn.setRequestMethod("POST");
+                    conn.setRequestProperty("Connection", "Keep-Alive");
+                    conn.setRequestProperty("ENCTYPE", "multipart/form-data");
+                    conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
+                    conn.setRequestProperty("f_file", fileName);
+
+                    dos = new DataOutputStream(conn.getOutputStream());
+
+                    dos.writeBytes(twoHyphens + boundary + lineEnd);
+                    dos.writeBytes("Content-Disposition: form-data; name=\"f_hwintro\""+ lineEnd + lineEnd);
+                    dos.writeBytes("" + lineEnd);
+                    dos.writeBytes(twoHyphens + boundary + lineEnd);
+                    dos.writeBytes("Content-Disposition: form-data; name=\"f_file\";filename=\""
+                                    + fileName + "\"" + lineEnd);
+
+                    dos.writeBytes(lineEnd);
+
+                    // create a buffer of  maximum size
+                    bytesAvailable = fileInputStream.available();
+
+                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
+                    buffer = new byte[bufferSize];
+
+                    // read file and write it into form...
+                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);
+                    while (bytesRead > 0) {
+
+                        dos.write(buffer, 0, bufferSize);
+                        bytesAvailable = fileInputStream.available();
+                        bufferSize = Math.min(bytesAvailable, maxBufferSize);
+                        bytesRead = fileInputStream.read(buffer, 0, bufferSize);
+
+                    }
+
+                    // send multipart form data necesssary after file data...
+                    dos.writeBytes(lineEnd);
+                    dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
+
+
+
+        // Responses from the server (code and message)
+        serverResponseCode = conn.getResponseCode();
+        String serverResponseMessage = conn.getResponseMessage();
+        try{
+            BufferedReader br = null;
+            if (200 <= serverResponseCode && serverResponseCode <= 299) {
+                br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
+            } else {
+                br = new BufferedReader(new InputStreamReader(conn.getErrorStream()));
+            }
+            StringBuilder sb = new StringBuilder();
+            String output;
+            while ((output = br.readLine()) != null) {
+                sb.append(output);
+            }
+
+            Log.e("Response", sb.toString());
+        } catch(java.io.IOException e){
+            e.printStackTrace();
+        }
+        Log.e("uploadFile", "HTTP Response is : "
+                + serverResponseMessage + ": " + serverResponseCode);
+
+        if(serverResponseCode == 200){
+
+            runOnUiThread(new Runnable() {
+                public void run() {
+
+                    String msg = "File Upload Completed.";
+
+                    messageText.setText(msg);
+                    Toast.makeText(MainActivity.this, "File Upload Complete.",
+                            Toast.LENGTH_SHORT).show();
+                }
+            });
+        }
+
+        //close the streams //
+        fileInputStream.close();
+        dos.flush();
+        dos.close();
+
+    } catch (MalformedURLException e) {
+
+        e.printStackTrace();
+
+
+
+        Log.e("Upload file to server", "error: " + e.getMessage(), e);
+    } catch (Exception e) {
+
+        e.printStackTrace();
+
+
+        Log.e("Upload", "Exception : "
+                + e.getMessage(), e);
+    }
+                return serverResponseCode;
+
+            } // End else block
+        */
+    }
+
+
+
+    public static String requestPost(String uri, Map<String, String> params){
+        HttpURLConnection conn;
+        DataOutputStream dos;
+        String response = null;
+        try {
+            // open a URL connection to the Servlet
+            URL url = new URL(uri);
+            // Open a HTTP  connection to  the URL
+            conn = (HttpURLConnection) url.openConnection();
+            conn.setDoInput(true); // Allow Inputs
+            conn.setDoOutput(true); // Allow Outputs
+            conn.setUseCaches(false); // Don't use a Cached Copy
+            conn.setRequestMethod("POST");
+            conn.setRequestProperty("Connection", "Keep-Alive");
+            dos = new DataOutputStream(conn.getOutputStream());
+
+            Set keySet = params.keySet();
+            StringBuilder sb = new StringBuilder();
+            for (Object objKey : keySet) {
+                //有了鍵就可以通過map集合的get方法獲取其對應的値
+
+                String key = objKey.toString();
+                String value = params.get(key);
+
+                sb.append(key).append("=").append(value).append("&");
+
+                Log.e("Params", "key: " + key + ", value: " + value);
+            }
+            if(params.size() != 0){
+                sb.deleteCharAt(sb.length()-1);
+            }
+
+            Log.e("StringBuilder", sb.toString());
+            dos.writeBytes(sb.toString());
+            
+
+            // Responses from the server (code and message)
+            int serverResponseCode = conn.getResponseCode();
+            String serverResponseMessage = conn.getResponseMessage();
+            try{
+                BufferedReader br;
+                if (200 <= serverResponseCode && serverResponseCode <= 299) {
+                    br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "big5"));
+                } else {
+                    br = new BufferedReader(new InputStreamReader(conn.getErrorStream(), "UTF-8"));
+                }
+                sb = new StringBuilder();
+                String output;
+                while ((output = br.readLine()) != null) {
+                    sb.append(output);
+                }
+                response = sb.toString();
+                Log.e("Response", response);
+            } catch(java.io.IOException e){
+                e.printStackTrace();
+            }
+            Log.e("uploadFile", "HTTP Response is : "
+                    + serverResponseMessage + ": " + serverResponseCode);
+
+            if(serverResponseCode == 200){
+
+                /*runOnUiThread(new Runnable() {
+                    public void run() {
+
+                        String msg = "File Upload Completed.";
+
+                        messageText.setText(msg);
+                        //Toast.makeText(MainActivity.this, "File Upload Completed.",
+                        //Toast.LENGTH_SHORT).show();
+                    }
+                });*/
+            }
+
+            dos.flush();
+            dos.close();
+
+        } catch (MalformedURLException e) {
+
+            e.printStackTrace();
+            Log.e("Upload file to server", "error: " + e.getMessage(), e);
+        } catch (Exception e) {
+            e.printStackTrace();
+            Log.e("Upload", "Exception : "
+                    + e.getMessage(), e);
+        }
+
+        return response;
+    }
+
+
+
+}

app/src/main/java/tech/goda/studyck/SharedPreferencesHelper.java

@@ -0,0 +1,76 @@
+package tech.goda.studyck;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+/**
+ * Created by Jerry on 2018/7/8.
+ */
+
+
+public class SharedPreferencesHelper {
+
+    private static final String SHARED_PREF_NAME = "KEYSTORE_SETTING";
+
+    private static final String PREF_KEY_AES = "PREF_KEY_AES";
+    private static final String PREF_KEY_IV = "PREF_KEY_IV";
+    private static final String PREF_KEY_INPUT = "PREF_KEY_INPUT";
+    public static final String PREF_AC = "PREF_AC";
+
+    private SharedPreferences sharedPreferences;
+
+
+
+    SharedPreferencesHelper(Context context){
+        sharedPreferences = context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
+    }
+
+
+    String getString(String key) {
+        return sharedPreferences.getString(key, "");
+    }
+
+    void putString(String key, String value) {
+        sharedPreferences.edit()
+                .putString(key, value)
+                .apply();
+    }
+
+    private boolean getBoolean(String key) {
+        return sharedPreferences.getBoolean(key, false);
+    }
+
+    private void putBoolean(String key, boolean value) {
+        sharedPreferences.edit()
+                .putBoolean(key, value)
+                .apply();
+    }
+
+
+
+
+    void setIV(String value) {
+        putString(PREF_KEY_IV, value);
+    }
+
+    String getIV() {
+        return getString(PREF_KEY_IV);
+    }
+
+    void setAESKey(String value) {
+        putString(PREF_KEY_AES, value);
+    }
+
+    String getAESKey() {
+        return getString(PREF_KEY_AES);
+    }
+
+    public void setInput(String value) {
+        putString(PREF_KEY_INPUT, value);
+    }
+
+    String getInput() {
+        return getString(PREF_KEY_INPUT);
+    }
+
+}

app/src/main/res/layout/activity_login.xml

@@ -0,0 +1,77 @@
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:gravity="center_horizontal"
+    android:orientation="vertical"
+    android:paddingBottom="@dimen/activity_vertical_margin"
+    android:paddingLeft="@dimen/activity_horizontal_margin"
+    android:paddingRight="@dimen/activity_horizontal_margin"
+    android:paddingTop="@dimen/activity_vertical_margin"
+    tools:context="tech.goda.studyck.LoginActivity">
+
+    <!-- Login progress -->
+    <ProgressBar
+        android:id="@+id/login_progress"
+        style="?android:attr/progressBarStyleLarge"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:visibility="gone" />
+
+    <ScrollView
+        android:id="@+id/login_form"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            android:id="@+id/email_login_form"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <AutoCompleteTextView
+                    android:id="@+id/email"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_email"
+                    android:inputType="textEmailAddress"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <EditText
+                    android:id="@+id/password"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_password"
+                    android:imeActionId="6"
+                    android:imeActionLabel="@string/action_sign_in_short"
+                    android:imeOptions="actionUnspecified"
+                    android:inputType="textPassword"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <Button
+                android:id="@+id/email_sign_in_button"
+                style="?android:textAppearanceSmall"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:text="@string/action_sign_in"
+                android:textStyle="bold" />
+
+        </LinearLayout>
+    </ScrollView>
+</LinearLayout>

app/src/main/res/layout/activity_main.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/mainActivity"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -7,12 +8,83 @@
     tools:context="tech.goda.studyck.MainActivity">
 
     <TextView
+        android:id="@+id/messageText"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
         android:text="Hello World!"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.29000002" />
+
+    <Button
+        android:id="@+id/uploadButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:text="Upload"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@+id/guideline"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/messageText"
+        app:layout_constraintVertical_bias="1.0" />
+
+    <Button
+        android:id="@+id/choose"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:text="Choose"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/guideline"
+        app:layout_constraintTop_toTopOf="@+id/messageText"
+        app:layout_constraintVertical_bias="1.0" />
+
+    <EditText
+        android:id="@+id/fileName"
+        android:layout_width="218dp"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:ems="10"
+        android:inputType="textPersonName"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/messageText"
+        app:layout_constraintVertical_bias="0.13" />
+
+    <Button
+        android:id="@+id/button3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:text="Request Test"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/fileName"
+        app:layout_constraintVertical_bias="0.268" />
+
+    <android.support.constraint.Guideline
+        android:id="@+id/guideline"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        app:layout_constraintGuide_percent="0.5" />
 
 </android.support.constraint.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -1,3 +1,17 @@
 <resources>
     <string name="app_name">StudyCK</string>
+    <string name="title_activity_login">Sign in</string>
+
+    <!-- Strings related to login -->
+    <string name="prompt_email">Account</string>
+    <string name="prompt_password">Password</string>
+    <string name="action_sign_in">Sign</string>
+    <string name="action_sign_in_short">Sign in</string>
+    <string name="error_invalid_email">This email address is invalid</string>
+    <string name="error_invalid_password">This password is too short</string>
+    <string name="error_incorrect_password">Account or password is incorrect</string>
+    <string name="error_field_required">This field is required</string>
+    <string name="permission_rationale">"Contacts permissions are needed for providing email
+        completions."
+    </string>
 </resources>