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：

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：

<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：

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.csdn.net/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。