android上显示网络图片

转载自：传智播客教程

1.先在j2ee项目上做一个测试项目，得到网络图片并生成文件。

package cn.itcast.net;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class ImageRequest {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        URL url = new URL("http://i3.itc.cn/20100707/76c_0969b700_d5b4_41cd_8243_9b486be92cc4_0.jpg");
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5 * 1000);
        InputStream inStream = conn.getInputStream();//通过输入流获取图片数据
        byte[] data = readInputStream(inStream);//得到图片的二进制数据
        File imageFile = new File("itcast.jpg");
        FileOutputStream outStream = new FileOutputStream(imageFile);
        outStream.write(data);
        outStream.close();
    }

    public static byte[] readInputStream(InputStream inStream) throws Exception{
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while( (len=inStream.read(buffer)) != -1 ){
            outStream.write(buffer, 0, len);
        }
        inStream.close();
        return outStream.toByteArray();
    }
}

2.在andorid上开发：

main.xml

<?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"
    >
    <TextView  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/urlpath"
        />
        
    <EditText  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="http://i3.itc.cn/20100707/76c_0969b700_d5b4_41cd_8243_9b486be92cc4_0.jpg"
        android:id="@+id/urlpath"
        />
        
    <Button
         android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:text="@string/button"
        android:id="@+id/button"
        />
        
    <ImageView
         android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:id="@+id/imageView"
        />    
</LinearLayout>

 

 

package cn.itcast.image;

import cn.itcast.service.ImageService;
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.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

public class ImageShowActivity extends Activity {
    private static final String TAG = "ImageShowActivity";
    private EditText pathText;
    private ImageView imageView;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        pathText = (EditText) this.findViewById(R.id.urlpath);
        imageView = (ImageView) this.findViewById(R.id.imageView);
        Button button = (Button)this.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String path = pathText.getText().toString();
                try {
                    byte[] data = ImageService.getImage(path);
                    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);//生成位图
                    imageView.setImageBitmap(bitmap);//显示图片                    
                } catch (Exception e) {
                    Toast.makeText(ImageShowActivity.this, R.string.error, 1).show();
                    Log.e(TAG, e.toString());
                }
            }
        });
    }
}

 

 

package cn.itcast.service;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import cn.itcast.utils.StreamTool;

public class ImageService {
    
    public static byte[] getImage(String path) throws Exception {
        URL url = new URL("http://i3.itc.cn/20100707/76c_0969b700_d5b4_41cd_8243_9b486be92cc4_0.jpg");
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5 * 1000);
        InputStream inStream = conn.getInputStream();//通过输入流获取图片数据
        return StreamTool.readInputStream(inStream);//得到图片的二进制数据
    }

}

 

 

package cn.itcast.utils;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class StreamTool {

    /**
     * 从输入流中获取数据
     * @param inStream 输入流
     * @return
     * @throws Exception
     */
    public static byte[] readInputStream(InputStream inStream) throws Exception{
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while( (len=inStream.read(buffer)) != -1 ){
            outStream.write(buffer, 0, len);
        }
        inStream.close();
        return outStream.toByteArray();
    }
}