Android How to - Download Image from a URL








The following code shows how to Download Image from a URL.

Example

Manifest xml file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.java2s.myapplication3.app" >

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="java2s.com"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.java2s.myapplication3.app.MainActivity"
            android:label="java2s.com"
            >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

Main layout xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center">
    
  <Button android:id="@+id/button"
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content"
      android:text="Download file"
      android:onClick="startDownload" 
      />
   <TextView android:id="@+id/status"
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content"
      android:text="click to start"
   />
</LinearLayout>

Main Activity Java code

package com.java2s.myapplication3.app;
/* w  w  w  . ja  v  a  2  s  .  c o  m*/
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

import java.net.URL;

public class MainActivity extends Activity {

    private Runnable imageDownloader = new Runnable() {

        public void run() {
            try {
                URL imageUrl = new URL("http", "android.com", "/images/froyo.png");
                Bitmap image = BitmapFactory.decodeStream(imageUrl.openStream());
                if (image != null) {
                    Log.i("DL", "Successfully retrieved file!");
                } else {
                    Log.i("DL", "Failed decoding file from stream");
                }
            } catch (Exception e) {
                Log.i("DL", "Failed downloading file!");
                e.printStackTrace();
            }
        }
    };

    public void startDownload(View source) {
        new Thread(imageDownloader, "Download thread").start();
        TextView statusText = (TextView) findViewById(R.id.status);
        statusText.setText("Download started...");
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}
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