Data not being stored when using Spring JPA with android

I am developing an app which would talk to the server which is developed using spring. I got to a point where we i was getting data from the google api and wanted to pass it to the spring server. But when i do pass it, the server accepts it but the data is not being stored in the mysql database.

Here is the code I am using:

This is the main spring application + controller:

@EnableJpaRepositories(basePackageClasses = StudentRepository.class)

@SpringBootApplication
public class Demo3Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo3Application.class, args);
    }
}

@RestController
class StudentController
{
    @Autowired
    public StudentRepository students;

    @RequestMapping(value = "/getstudent", method = RequestMethod.GET)
    public @ResponseBody List<Student> fetchStudents() 
    {  

        if(students.count() ==  0)
        {
            Vector<VideoList> no_video = new Vector<VideoList>();
            VideoList no_v = new VideoList("No Videos found", null, null, null);
            no_video.add(no_v);
            return no_video;
            return null;
        }

        return null;
    }

    @RequestMapping(value = "/poststudent" , method = RequestMethod.POST)
    public @ResponseBody String putStudents(@RequestBody Student v )
    {

        students.save(v);

        return "Student Successfully Added";


    }

    @RequestMapping(value = "/searchstudent/{str}" , method = RequestMethod.GET)
    public @ResponseBody String searchStudent(
        @PathVariable("str")    String searchQuery
        )
    {   
        if(students.existsByEmail(searchQuery)){
            List<Student> sList = students.findEmail(searchQuery,new PageRequest(0, 1));
            Student s = sList.get(0);
            String str = "";
             Vector<CourseList> c = s.getCourses();
             Iterator<CourseList> it = c.iterator();
             while(it.hasNext()){
                 str.concat(it.next().toString());
                 str.concat("\n");
             }
             return str;
        }

        return null ;

    }

    @RequestMapping(value = "/addcourse" , method = RequestMethod.POST)
    public @ResponseBody String postCourse(@RequestParam String email, @RequestParam String course){
        List<Student> sList = students.findEmail(email,new PageRequest(0, 1));
        Student s = sList.get(0);
        CourseList c = new CourseList();
        c.setName(course);
        s.addCourse(c);
        students.save(s);
        return null;
    }

}

This is the Student class:

@Entity
@Table(name = "table1")
public class Student {

    private String name;    

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int id;

    private String email;

    private Vector<CourseList> courses = new Vector<CourseList>();//CourseList is just a class to store data about various courses.
    public Student(){}
    public String getName(){
        return name;
    }
    public String getEmail(){
        return email;
    }
    public Vector<CourseList> getCourses(){
        return courses;
    }
    public void setName(String name){
        this.name = name;
    }
    public void setEmail(String email){
        this.email = email;
    }
    public void setCourses(Vector<CourseList> courses){
        this.courses = courses;
    }
    public void addCourse(CourseList c){
        courses.add(c);
    }
}

This is my repository:

@Repository
@Transactional
public interface StudentRepository extends CrudRepository<Student,String>{

    @Query("SELECT s FROM Student s WHERE email = ?1")
    public List<Student> findEmail(String searchQuery, Pageable pageable);

    @Query("SELECT CASE WHEN COUNT(s) > 0 THEN 'true' ELSE 'false' END FROM Student s WHERE s.email = ?1")
    public boolean existsByEmail(String searchQuery);


}

This is my application.properties file:

spring.datasource.url: jdbc:mysql://localhost/mydb
spring.datasource.driverClassName: com.mysql.jdbc.Driver
spring.datasource.username: root
spring.datasource.password:root

# Specify the DBMS
spring.jpa.database = MYSQL

# Show or not log for each sql query
spring.jpa.show-sql = true

# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update

# Naming strategy
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy

# Use spring.jpa.properties.* for Hibernate native properties (the prefix is
# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

And finally here is the android code to test the above:

public class MainActivity extends Activity implements OnClickListener,
        ConnectionCallbacks, OnConnectionFailedListener {

    private static final int RC_SIGN_IN = 0;
    // Logcat tag
    private static final String TAG = "MainActivity";

    // Profile pic image size in pixels
    private static final int PROFILE_PIC_SIZE = 400;

    // Google client to interact with Google API
    private GoogleApiClient mGoogleApiClient;

    /**
     * A flag indicating that a PendingIntent is in progress and prevents us
     * from starting further intents.
     */
    private boolean mIntentInProgress;

    private boolean mSignInClicked;

    private ConnectionResult mConnectionResult;

    private SignInButton btnSignIn;
    private Button btnSignOut;
    private ImageView imgProfilePic;
    private TextView txtName, txtEmail, course;
    private LinearLayout llProfileLayout;
    private Button SC;

    private String personName;
    private String personPhotoUrl;
    private String personGooglePlusProfile;
    private String email;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnSignIn = (SignInButton) findViewById(R.id.btn_sign_in);
        btnSignOut = (Button) findViewById(R.id.btn_sign_out);
        imgProfilePic = (ImageView) findViewById(R.id.imgProfilePic);
        txtName = (TextView) findViewById(R.id.txtName);
        course = (TextView) findViewById(R.id.txtCourses);
        txtEmail = (TextView) findViewById(R.id.txtEmail);
        llProfileLayout = (LinearLayout) findViewById(R.id.llProfile);
        SC=(Button)findViewById(R.id.Scourse);

        // Button click listeners
        btnSignIn.setOnClickListener(this);
        btnSignOut.setOnClickListener(this);
        SC.setOnClickListener(this);

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).addApi(Plus.API)
                .addScope(Plus.SCOPE_PLUS_LOGIN).build();
    }

    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    protected void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }

    /**
     * Method to resolve any signin errors
     * */
    private void resolveSignInError() {
        if (mConnectionResult.hasResolution()) {
            try {
                mIntentInProgress = true;
                mConnectionResult.startResolutionForResult(this, RC_SIGN_IN);
            } catch (SendIntentException e) {
                mIntentInProgress = false;
                mGoogleApiClient.connect();
            }
        }
    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {
        if (!result.hasResolution()) {
            GooglePlayServicesUtil.getErrorDialog(result.getErrorCode(), this,
                    0).show();
            return;
        }

        if (!mIntentInProgress) {
            // Store the ConnectionResult for later usage
            mConnectionResult = result;

            if (mSignInClicked) {
                // The user has already clicked 'sign-in' so we attempt to
                // resolve all
                // errors until the user is signed in, or they cancel.
                resolveSignInError();
            }
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int responseCode,
                                    Intent intent) {
        if (requestCode == RC_SIGN_IN) {
            if (responseCode != RESULT_OK) {
                mSignInClicked = false;
            }

            mIntentInProgress = false;

            if (!mGoogleApiClient.isConnecting()) {
                mGoogleApiClient.connect();
            }
        }
    }

    @Override
    public void onConnected(Bundle arg0) {
        mSignInClicked = false;
        Toast.makeText(this, "User is connected!", Toast.LENGTH_LONG).show();

        // Get user's information
        getProfileInformation();


        // Update the UI after signin
        updateUI(true);

    }

    /**
     * Updating the UI, showing/hiding buttons and profile layout
     * */
    private void updateUI(boolean isSignedIn) {
        if (isSignedIn) {
            btnSignIn.setVisibility(View.GONE);
            btnSignOut.setVisibility(View.VISIBLE);
            llProfileLayout.setVisibility(View.VISIBLE);
            getCourses();
            SC.setVisibility(View.VISIBLE);
        } else {
            btnSignIn.setVisibility(View.VISIBLE);
            btnSignOut.setVisibility(View.GONE);
            llProfileLayout.setVisibility(View.GONE);
            course.setText(" ");
            SC.setVisibility(View.GONE);
        }
    }

    private void getCourses(){
        new StudentSearch().execute();
    }



    private class StudentSearch extends AsyncTask<String, Void, String >
    {

        String content = "";
        @Override
        protected String doInBackground(String... urls) {

            HttpClient httpClient = new DefaultHttpClient();
            HttpGet httpget = new HttpGet("http://ift.tt/1Don8s7"+email);

            StringBuffer studentString = new StringBuffer();
            try {
                HttpResponse response = httpClient.execute(httpget);
                InputStream responseString = response.getEntity().getContent();

                BufferedReader reader = new BufferedReader(new InputStreamReader(responseString));
                String res = "";
                if ((res = reader.readLine()) == null) {
                    studentString.append("");
                    HttpPost httpPost = new HttpPost("http://ift.tt/1yH0v6s");

                    JSONObject jsonObject = new JSONObject();
                    try {
                        jsonObject.put("name", personName);
                        jsonObject.put("email", email);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }

                    try {
                        StringEntity se = new StringEntity(jsonObject.toString());
                        se.setContentType("application/json;charset=UTF-8");
                        se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json;charset=UTF-8"));
                        httpPost.setEntity(se);
                    } catch (UnsupportedEncodingException e) {
                        // writing error to Log
                        e.printStackTrace();
                    }

                } else {
                    studentString.append(res);
                    studentString.append("\n");
                    while ((res = reader.readLine()) != null) {
                        studentString.append(res);
                        studentString.append("\n");
                    }

                }
            }
            catch(Exception e)
            {
                e.printStackTrace();
            }

            return studentString.toString();
        }

        @Override
        protected void onPostExecute(String s) {
            if (!s.isEmpty()){
                course.setText("Courses Taken:\n"+s);}
            else
                course.setText("No Courses Taken!");

        }
    }

    /**
     * Fetching user's information name, email, profile pic
     * */
    private void getProfileInformation() {
        try {
            if (Plus.PeopleApi.getCurrentPerson(mGoogleApiClient) != null) {
                Person currentPerson = Plus.PeopleApi
                        .getCurrentPerson(mGoogleApiClient);
                personName = currentPerson.getDisplayName();
                personPhotoUrl = currentPerson.getImage().getUrl();
                personGooglePlusProfile = currentPerson.getUrl();
                email = Plus.AccountApi.getAccountName(mGoogleApiClient);

                Log.e(TAG, "Name: " + personName + ", plusProfile: "
                        + personGooglePlusProfile + ", email: " + email
                        + ", Image: " + personPhotoUrl);

                txtName.setText(personName);
                txtEmail.setText(email);

                // by default the profile url gives 50x50 px image only
                // we can replace the value with whatever dimension we want by
                // replacing sz=X
                personPhotoUrl = personPhotoUrl.substring(0,
                        personPhotoUrl.length() - 2)
                        + PROFILE_PIC_SIZE;

                new LoadProfileImage(imgProfilePic).execute(personPhotoUrl);

            } else {
                Toast.makeText(getApplicationContext(),
                        "Person information is null", Toast.LENGTH_LONG).show();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onConnectionSuspended(int arg0) {
        mGoogleApiClient.connect();
        updateUI(false);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        return true;
    }

    /**
     * Button on click listener
     * */
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_sign_in:
                // Signin button clicked
                signInWithGplus();
                break;
            case R.id.btn_sign_out:
                // Signout button clicked
                signOutFromGplus();
                break;
            case R.id.Scourse:
            {
                Intent intent=new Intent(MainActivity.this,SelectCourse.class);
                startActivity(intent);
                break;
            }
        }
    }

    /**
     * Sign-in into google
     * */
    private void signInWithGplus() {
        if (!mGoogleApiClient.isConnecting()) {
            mSignInClicked = true;
            resolveSignInError();
        }
    }

    /**
     * Sign-out from google
     * */
    private void signOutFromGplus() {
        if (mGoogleApiClient.isConnected()) {
            Plus.AccountApi.clearDefaultAccount(mGoogleApiClient);
            mGoogleApiClient.disconnect();
            mGoogleApiClient.connect();
            updateUI(false);
        }
    }

    /**
     * Background Async task to load user profile picture from url
     * */
    private class LoadProfileImage extends AsyncTask<String, Void, Bitmap> {
        ImageView bmImage;

        public LoadProfileImage(ImageView bmImage) {
            this.bmImage = bmImage;
        }

        protected Bitmap doInBackground(String... urls) {
            String urldisplay = urls[0];
            Bitmap mIcon11 = null;
            try {
                InputStream in = new java.net.URL(urldisplay).openStream();
                mIcon11 = BitmapFactory.decodeStream(in);
            } catch (Exception e) {
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            }
            return mIcon11;
        }

        protected void onPostExecute(Bitmap result) {
            bmImage.setImageBitmap(result);
        }
    }

}

I am a total newbie when it comes to developing spring code and would really appreciate some help.