1) Import Dependencies
The easiest way to add Volley to your project is to add the following dependency to your app's build.gradle file:
dependencies {
...
compile 'com.android.volley:volley:1.0.0'
}
2) Add Internet Permission On Manifest File
<uses-permission android:name="ANDROID.PERMISSION.INTERNET" />
3) Main Activity Design
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.ismails.myapplication.MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="JSON Data Here"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="104dp"
android:id="@+id/jsonData"
android:textColor="#000000"
android:textStyle="bold"
android:textSize="20dp"
android:textAlignment="center"/>
<Button
android:id="@+id/btn_json"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="79dp"
android:text="Get JSON Data" />
</RelativeLayout>
3) Main Activity Java
public class MainActivity extends AppCompatActivity {
// Todo : Will show the string "data" that holds the results
TextView results;
// Todo : URL of object to be parsed
String JsonURL = "http://jsonplaceholder.typicode.com/todos/1";
// Todo : Defining the Volley request queue that handles the URL request concurrently
RequestQueue requestQueue;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Todo : Creates the Volley request queue
requestQueue = Volley.newRequestQueue(this);
// Todo : Casts results into the TextView And Button found within the main layout XML with id jsonData
results = (TextView) findViewById(R.id.jsonData);
btn = (Button)findViewById(R.id.btn_json);
/*Todo : Set OnClick To Get JSON Data In TextView*/
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Todo : Creating the JsonObjectRequest class called obreq, passing required parameters:
// Todo : GET is used to fetch data from the server, JsonURL is the URL to be fetched from.
JsonObjectRequest jsObjRequest = new JsonObjectRequest
(Request.Method.GET, JsonURL, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
/*Todo : Assign Json Value In TextView*/
results.setText("JSON Data Is \n: " + response.toString());
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// TODO Auto-generated method stub
}
});
// Todo : Adds the JSON object request "jsObjRequest" to the request queue
requestQueue.add(jsObjRequest);
}
});
}
}
