使用http协议获取网络图片

http用于传输WWW方式的数据。http协议采用了请求响应的模型。在android中提供了HttpURLConnection和HttpClient接口开发HTTP程序。下面分别使用这两种方式获取网络图片。

          1.HttpURLConnection

          代码如下：

   

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1. public class HttpURLConnectionActivity extends Activity {  
2.   
3.     private ImageView imageView;  
4.     @Override  
5.     protected void onCreate(Bundle savedInstanceState) {  
6.         // TODO Auto-generated method stub  
7.         super.onCreate(savedInstanceState);  
8.         setContentView(R.layout.simple1);  
9.           
10.         imageView=(ImageView) this.findViewById(R.id.imageView1);  
11.         //传入网络图片地址  
12.         try {  
13.             URL url = new URL("http://news.xinhuanet.com/photo/2012-02/09/122675973_51n.jpg");  
14.             HttpURLConnection conn= (HttpURLConnection) url.openConnection();  
15.             conn.setRequestMethod("GET");  
16.             conn.setConnectTimeout(5*1000);  
17.             conn.connect();  
18.             InputStream in=conn.getInputStream();  
19.             ByteArrayOutputStream bos=new ByteArrayOutputStream();  
20.             byte[] buffer=new byte[1024];  
21.             int len = 0;  
22.             while((len=in.read(buffer))!=-1){  
23.                 bos.write(buffer,0,len);  
24.             }  
25.             byte[] dataImage=bos.toByteArray();  
26.             bos.close();  
27.             in.close();  
28.             Bitmap bitmap=BitmapFactory.decodeByteArray(dataImage, 0, dataImage.length);  
29.             //Drawable drawable=BitmapDrawable.  
30.             imageView.setImageBitmap(bitmap);  
31.         } catch (Exception e) {  
32.             // TODO Auto-generated catch block  
33.             e.printStackTrace();  
34.             Toast.makeText(getApplicationContext(), "图片加载失败", 1).show();  
35.         }  
36.           
37.     }  
38. }  

public class HttpURLConnectionActivity extends Activity {

	private ImageView imageView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.simple1);
		
		imageView=(ImageView) this.findViewById(R.id.imageView1);
		//传入网络图片地址
		try {
			URL url = new URL("http://news.xinhuanet.com/photo/2012-02/09/122675973_51n.jpg");
			HttpURLConnection conn= (HttpURLConnection) url.openConnection();
			conn.setRequestMethod("GET");
			conn.setConnectTimeout(5*1000);
			conn.connect();
			InputStream in=conn.getInputStream();
			ByteArrayOutputStream bos=new ByteArrayOutputStream();
			byte[] buffer=new byte[1024];
			int len = 0;
			while((len=in.read(buffer))!=-1){
				bos.write(buffer,0,len);
			}
			byte[] dataImage=bos.toByteArray();
			bos.close();
			in.close();
			Bitmap bitmap=BitmapFactory.decodeByteArray(dataImage, 0, dataImage.length);
			//Drawable drawable=BitmapDrawable.
	        imageView.setImageBitmap(bitmap);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			Toast.makeText(getApplicationContext(), "图片加载失败", 1).show();
		}
		
	}
}

           最后不要忘记在manifest.xml加入网络访问权限：

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

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

         由于访问网络图片是比较耗时的操作，所以在正式项目中使用异步加载图片，效果会更好。

         运行效果：

       

         2.HttpClient

          下面使用HttpClient获取网页内容：

        

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1. public class HttpClientActivity extends Activity {  
2.   
3.     private ImageView imageview;  
4.     private TextView text;  
5.     @Override  
6.     protected void onCreate(Bundle savedInstanceState) {  
7.         // TODO Auto-generated method stub  
8.         super.onCreate(savedInstanceState);  
9.         setContentView(R.layout.simple2);  
10.           
11.         imageview=(ImageView) this.findViewById(R.id.imageView2);  
12.         text=(TextView) this.findViewById(R.id.textView2);  
13.         HttpGet httpGet=new HttpGet("http://cloud.youkuaiyun.com/a/20120209/311628.html");  
14.         HttpClient httpClient=new DefaultHttpClient();  
15.         try {  
16.             //得到HttpResponse对象  
17.             HttpResponse httpResponse=httpClient.execute(httpGet);  
18.             //HttpResponse的返回结果是不是成功  
19.             if(httpResponse.getStatusLine().getStatusCode()==HttpStatus.SC_OK){  
20.                 //得到返回数据的字符串  
21.                 String dataImageStr=EntityUtils.toString(httpResponse.getEntity());  
22.                 text.setText(dataImageStr);  
23.             }  
24.         } catch (ClientProtocolException e) {  
25.             // TODO Auto-generated catch block  
26.             e.printStackTrace();  
27.         } catch (IOException e) {  
28.             // TODO Auto-generated catch block  
29.             e.printStackTrace();  
30.         }  
31.     }  
32. }  

public class HttpClientActivity extends Activity {

	private ImageView imageview;
	private TextView text;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.simple2);
		
		imageview=(ImageView) this.findViewById(R.id.imageView2);
		text=(TextView) this.findViewById(R.id.textView2);
		HttpGet httpGet=new HttpGet("http://cloud.youkuaiyun.com/a/20120209/311628.html");
		HttpClient httpClient=new DefaultHttpClient();
		try {
			//得到HttpResponse对象
			HttpResponse httpResponse=httpClient.execute(httpGet);
			//HttpResponse的返回结果是不是成功
			if(httpResponse.getStatusLine().getStatusCode()==HttpStatus.SC_OK){
				//得到返回数据的字符串
				String dataImageStr=EntityUtils.toString(httpResponse.getEntity());
				text.setText(dataImageStr);
			}
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

       运行效果：

      

        这样就成功加载了网页内容。