I am trying to do a JSON POST Request in android studio and my app keeps crashing and wont go through....Whats wroung?

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search);
        searchActivity.this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
        Toolbar toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setHomeButtonEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        mEditText = (EditText) findViewById(R.id.Edit_Text);
        mButton = (Button) findViewById(R.id.Postbutton);

        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                System.out.println(mButton);
                String readText = mEditText.getText() + " ";
                System.out.print(readText.length());
                if (readText.length() == 1) {
                    Toast toast = Toast.makeText(getApplicationContext(),
                            "Please Enter a Question", Toast.LENGTH_SHORT);
                    toast.setGravity(Gravity.CENTER | Gravity.CENTER_HORIZONTAL, 0, 0);
                    toast.show();
                    return;
                }
                mVolleySingleton = VolleySingleton.getInstance();
                mRequestQueue = mVolleySingleton.getRequestQueue();
                JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, insertUrl,new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        System.out.println(response+"reponse");

                    }

                }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        System.out.println(error+"error");
                    }
                }){
                    @Override
                    protected Map<String, String> getParams() throws AuthFailureError {
                        Map<String,String>parameters=new HashMap<String, String>();
                        parameters.put("text", mEditText.getText().toString());
                        parameters.put("id", "0");
                        parameters.put("studentId", "1");
                        System.out.println(parameters+"parameters");
                        return parameters;

                    }
                    @Override
                    public Map<String, String> getHeaders() throws AuthFailureError {
                        Map<String,String> params = new HashMap<String, String>();
                        params.put("content-type", "application/json; charset=utf-8");

                        System.out.println(params);

                        return params;
                    }
                };
                System.out.println(request+"request");

                mrequestQueue.add(request);

            }
        });
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id=item.getItemId();
        if(id==R.id.action_settings){
            return true;
        }
        if(id==android.R.id.home){
            NavUtils.navigateUpFromSameTask(this);
        }
        return super.onOptionsItemSelected(item);
    }
}