Android Volley with REST Api - POST will not insert into dB and respons incorrectly - rest

Question

I am using https://github.com/mevdschee/php-crud-api as REST Api to access my MySQL db. To access data from Android application I use Volley lib.
All works fine except POST (creating new item in db). But instead new item created I am getting JSON will all items (look like output from GET) and item is not created in dB.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(TAG, "APP START");
tv = findViewById(R.id.textView);
buttonPost = findViewById(R.id.buttonPost);
buttonGet = findViewById(R.id.buttonGet);
Calendar cal = Calendar.getInstance();
SimpleDateFormat sd1 = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
current_date = sd1.format(new Date(cal.getTimeInMillis()));
Log.d(TAG, "current_date=" + current_date);
cache = new DiskBasedCache(getCacheDir(), 1024 * 1024); // 1MB cap
mRequestQueue = new RequestQueue(cache, network);
mRequestQueue.start();
buttonGet.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d(TAG, "ButtonGet pressed");
tv.setText("");
getRest();
}
});
buttonPost.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d(TAG, "ButtonPost pressed");
tv.setText("");
postRest();
}
});
}
getRest()
tv.append("REST API - reading data via GET " + "\n");
JsonObjectRequest jsObjRequest = new JsonObjectRequest(Request.Method.GET, endpointUrl, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONObject vancuraLevel1 = response.getJSONObject("restdemo");
JSONArray vancuraLevel2 = vancuraLevel1.getJSONArray("records");
int JSONlenght2 = vancuraLevel2.length();
Log.d("JSON", "JSONlenght2 =" + JSONlenght2 );
for(int n = 0; n < JSONlenght2; n++) {
Log.d("JSON", "looping " + n );
JSONArray vancuraLevel3 = vancuraLevel2.getJSONArray(n);
int JSONlenght3 = vancuraLevel3.length();
String index = vancuraLevel3.getString(0);
String datum = vancuraLevel3.getString(1);
String subjekt = vancuraLevel3.getString(2);
String ovoce = vancuraLevel3.getString(3);
Log.d("JSON", "result datum" + datum + " subjekt=" + subjekt);
tv.append("Data : " + index + "/" + datum + "/" + subjekt + "/" + ovoce + "\n");
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Volley REST error " + error.toString());
tv.append("ERROR " + error.toString() +"\n");
}
});
// fire Volley request
mRequestQueue.add(jsObjRequest);
postRest(){
final String whatToInsert = "foo subjekt " + current_date;
// POST - insert data
tv.append("REST API - inserting data via POST - payload=" + whatToInsert +"\n");
StringRequest postRequest = new StringRequest(Request.Method.POST, endpointUrl, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// response
Log.d("Response", response);
// tv.append(current_date + "\n");
tv.append("response = " + response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// error
Log.e("Error.Response", error.getMessage());
tv.append("ERROR " + error.toString() +"\n");
}
})
{
#Override
protected Map<String, String> getParams()
{
Map<String, String> params = new HashMap<String, String>();
//params.put("index", "NULL");
params.put("datum", "2017-12-30");
params.put("subjekt", whatToInsert);
params.put("ovoce", "2");
return params;
}
};
// fire Volley request
mRequestQueue.add(postRequest);
Result GET - it is OK
Result POST - fault
project is available at https://github.com/fanysoft/AndroidRESTapi

Answer 1

Looking closely at the code the GET method returns a JSONObject response while the POST method return a String response. The string response of the POST Method is very correct and it carries exactly the same result as the GET method result all you have to do is convert the String response to JSON object you ll have same JSONObject as the GET method
JSONObject jsonObject = new JSONObject(response);
Then you can parse the object for your result

Answer 2

Solved by disabling Volley cache
getRequest.setShouldCache(false);
postRequest.setShouldCache(false);