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.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。