Android Load Image from URL

By Arvind Rai, August 24, 2015

This page covers Android load image from URL with Internet using BitmapFactory and ImageView.setImageBitmap() example. To work with internet we need a separate thread otherwise we will get android.os.NetworkOnMainThreadException. To handle this situation, we can use AsyncTask. Optionally we can also use StrictMode.ThreadPolicy. In our layout, we need to create a tag for ImageView. To work with internet, we need permission in AndroidManifest.xml as follows.

<uses-permission android:name="android.permission.INTERNET"/>

Load Image using AsyncTask

To load image with AsyncTask, we need to create a sub class of it where we will define doInBackground() and onPostExecute(). doInBackground() loads the image and once loaded it is set to ImageView within onPostExecute() method. Find the class.
AsyncTaskLoadImage.java

package com.concretepage;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.ImageView;
public class AsyncTaskLoadImage  extends AsyncTask<String, String, Bitmap> {
    private final static String TAG = "AsyncTaskLoadImage"; 
    private ImageView imageView;
    public AsyncTaskLoadImage(ImageView imageView) {
	this.imageView = imageView;
    }
    @Override
    protected Bitmap doInBackground(String... params) {
    	Bitmap bitmap = null;
    	try {
        	URL url = new URL(params[0]);
                bitmap = BitmapFactory.decodeStream((InputStream)url.getContent());
	} catch (IOException e) {
		Log.e(TAG, e.getMessage());
	}
        return bitmap;
    }
    @Override
    protected void onPostExecute(Bitmap bitmap) {
		imageView.setImageBitmap(bitmap);
    }
}

Load Image using StrictMode.ThreadPolicy

We can also use StrictMode.ThreadPolicy just before calling ImageView.setImageBitmap() that avoids android.os.NetworkOnMainThreadException. Find the code snippet.

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

Main Activity

MainActivity.java

package com.concretepage;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import android.app.Activity;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.ImageView;
public class MainActivity extends Activity {
	private final static String TAG = "MainActivity"; 
	private ImageView imageView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
    	        imageView = (ImageView)findViewById(R.id.image);
	}
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
               getMenuInflater().inflate(R.menu.menu_main, menu);
               return true;
        }
        public void showImageOne(View v) {
    	       String url = "https://www.gstatic.com/webp/gallery3/1.sm.png";
    	       new AsyncTaskLoadImage(imageView).execute(url);
        }
        public void showImageTwo(View v) {
    	       StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    	       StrictMode.setThreadPolicy(policy);
    	       try {
        	   URL url = new URL("https://www.gstatic.com/webp/gallery/4.sm.jpg");
		   imageView.setImageBitmap(BitmapFactory.decodeStream((InputStream)url.getContent()));
	       } catch (IOException e) {
		   Log.e(TAG, e.getMessage());
	       }
        }    
}

Other XML Files

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.concretepage"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="16"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <application 
        android:allowBackup ="false"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity  android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"    
    tools:context=".MainActivity"
    android:id="@+id/myLayout">
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btnmsg1"
        android:onClick="showImageOne"/>
    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btnmsg2"
        android:onClick="showImageTwo"/>
    <ImageView
	android:id="@+id/image"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="#000000"
	android:gravity="center"
	android:padding="32dp"
	android:contentDescription="@string/imgDesc"/>
</LinearLayout>

res/layout/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Concretepage</string>
    <string name="imgDesc">Image Description</string>
    <string name="btnmsg1">Click to Show Image One</string>
    <string name="btnmsg2">Click to Show Image Two</string>
</resources>