Introduction To Volley
Using Android Studio 1.4
Application Name: MyFirstVolleyProject1
Select API 14:Android 4.0 (IceCreamSandwich)
Follow the wizard to create New Blank Activity.
Download volley20151105.zip and unzip it.
Build.Gradle(Module:App)
apply plugin: 'com.android.application' android { compileSdkVersion 23 buildToolsVersion "23.0.1" defaultConfig { applicationId "com.notarazi.myfirstvolleyproject1" minSdkVersion 14 targetSdkVersion 23 versionCode 1 versionName "1.0" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) testCompile 'junit:junit:4.12' compile 'com.android.support:appcompat-v7:23.1.0' compile 'com.android.support:design:23.1.0' compile project(':volley') } |
Sync Project with Gradle Files
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.notarazi.myfirstvolleyproject1" > <uses-permission android:name="android.permission.INTERNET"/> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="@string/app_name" android:theme="@style/AppTheme.NoActionBar" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest> |
If you missed this step, your debug message will tell you about this.
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" app:layout_behavior="@string/appbar_scrolling_view_behavior" tools:showIn="@layout/activity_main" tools:context=".MainActivity"> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Blog Posts" android:textStyle="bold" android:id="@+id/heading" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:textSize="38dp" android:textColor="#230cff" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge" android:text="Small Text" android:textSize="12dp" android:textStyle="bold" android:id="@+id/jsonData" android:layout_marginTop="42dp" android:layout_below="@+id/heading" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" android:textColor="#000000" /> </LinearLayout> </RelativeLayout> |
package com.notarazi.myfirstvolleyproject1; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; import com.android.volley.Request; import com.android.volley.RequestQueue; import com.android.volley.Response; import com.android.volley.VolleyError; import com.android.volley.toolbox.JsonObjectRequest; import com.android.volley.toolbox.Volley; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; public class MainActivity extends AppCompatActivity { TextView output ; String loginURL="https://public-api.wordpress.com/rest/v1/sites/www.hackpundit.com/posts?number=5&page=1&type=post&fields=id,title,URL"; String data = ""; RequestQueue requestQueue; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); if(savedInstanceState!=null){ Log.d("STATE", savedInstanceState.toString()); } Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); sendRequest(); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) .setAction("Action", null).show(); } }); } private void sendRequest() { requestQueue = Volley.newRequestQueue(this); output = (TextView) findViewById(R.id.jsonData); JsonObjectRequest jor = new JsonObjectRequest(Request.Method.GET, loginURL, null, new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { try{ JSONArray ja = response.getJSONArray("posts"); for(int i=0; i < ja.length(); i++){ JSONObject jsonObject = ja.getJSONObject(i); // int id = Integer.parseInt(jsonObject.optString("id").toString()); String title = jsonObject.getString("title"); String url = jsonObject.getString("URL"); data += "Blog Number "+(i+1)+" \n Blog Name= "+title +" \n URL= "+ url +" \n\n\n\n "; } output.setText(data); }catch(JSONException e){e.printStackTrace();} } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { Log.e("Volley","Error"); } } ); requestQueue.add(jor); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } } |
http://www.hackpundit.com/android-turorial-json-parse-volley/