Go语言视频零基础入门到精通

水中月

   既然Android定位为“网络操作系统”，自然提供了很威水的网络访问接口。既有java.net.*,又有org.apache.http.*，在数据处理方面支持json，xml等常用的数据格式。

Java代码： public class HttpDemo extends Activity {

private static final int MSGWHAT = 0x000000;

private TextView textView;

private Button btnLink;

private EditText etUrl;

private String data;

/**

* 消息控制器，用来更新界面，因为在普通线程是无法用来更新界面的

*/

private Handler handler = new Handler() {

@Override

public void handleMessage(Message msg) {

switch (msg.what) {

case MSGWHAT:

//设置显示文本

textView.setText(data);

break;

default:

break;

}

}

};

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

//注意界面控件的初始化的位置,不要放在setContentView()前面

initComponent();

btnLink.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

//可以放在另外的线程完成

try {

data = getData();

} catch (ClientProtocolException e) {

data = e.getMessage();

} catch (IOException e) {

data = e.getMessage();

} catch (URISyntaxException e) {

data = e.getMessage();

}

Message msg = new Message();

msg.what = MSGWHAT;

handler.sendMessage(msg);

}

});

}

/**

* 初始化界面组件

*/



private void initComponent() {

textView = (TextView) findViewById(R.id.text);

btnLink = (Button) findViewById(R.id.btn_link);

etUrl = (EditText) findViewById(R.id.url);

}

/**

* 取数据

* @return

* @throws ClientProtocolException

* @throws IOException

* @throws URISyntaxException

*/



private String getData() throws ClientProtocolException, IOException, URISyntaxException {

String urlString = etUrl.getText().toString();

return request(urlString);

}

/**

* 发送请求

* @param url 请求地址

* @return

* @throws ClientProtocolException

* @throws IOException

* @throws URISyntaxException

*/



private String request(String url) throws ClientProtocolException, IOException, URISyntaxException {

HttpClient httpClient = new DefaultHttpClient();

URI uri = URIUtils.createURI("http", url, -1, null, null, null);

HttpGet get = new HttpGet(uri);

ResponseHandler<String> responseHandler = new BasicResponseHandler();

return httpClient.execute(get, responseHandler);

}

@Override

protected void onDestroy() {

super.onDestroy();

System.gc();

System.exit(0);

}



}
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