ANDROID HttpURLConnection,HttpClient和最简单的handler机制

handler机制在Android开发中主要用于主线程和子线程的沟通，子线程发送必要的信息给主线程，然后在主线程中更新ui；

package com.example.webview;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.URL;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v7.app.ActionBarActivity;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends ActionBarActivity implements OnClickListener{public static final int SHOW_RESPONSE=0;private TextView reponseText;private Button sendButton;private Handler handler=new Handler(){/* (non-Javadoc) * @see android.os.Handler#handleMessage(android.os.Message) */@Overridepublic void handleMessage(Message msg) {//接收消息并且去更新UI线程上的控件内容switch (msg.what) {case SHOW_RESPONSE:String response=(String) msg.obj;reponseText.setText(response);break;default:Toast.makeText(MainActivity.this, "show fail!!", Toast.LENGTH_SHORT).show();break;}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sendButton=(Button) findViewById(R.id.send_request_id);reponseText=(TextView) findViewById(R.id.text_id);sendButton.setOnClickListener(this);}/* (non-Javadoc) * @see android.view.View.OnClickListener#onClick(android.view.View) */@Overridepublic void onClick(View v) {sendRequestWithHttpURLConnection();Toast.makeText(MainActivity.this, "onclick!1", Toast.LENGTH_SHORT).show();}/** * 开启线程来发起网路请求 */private void sendRequestWithHttpURLConnection() {new Thread(new Runnable() {@Overridepublic void run() {HttpURLConnection connection=null;try {URL url=new URL("http://www.baidu.com");connection=(HttpURLConnection) url.openConnection();connection.setRequestMethod("GET");//设置连接超时connection.setConnectTimeout(8000);//设置读取超时connection.setReadTimeout(8000);//获取输入流，进行读取InputStream inputStream=connection.getInputStream();BufferedReader reader=new BufferedReader(new InputStreamReader(inputStream));//下面这个StringBuilder 的作用相当于一个StringStringBuilder response=new StringBuilder();while (reader.readLine()!=null) {//读一行就，把读到的添加到response里面response.append(reader.readLine());}//调用dandler的obtainmessage方法，得到一个message对象Message message=handler.obtainMessage();/*一个message对象，public static Message obtain(Handler h, int what, int arg1, int arg2, Object obj)，h：处理消息的目标Handler对象；what：消息的编码；arg1：附加的整数数据；arg2：附加的整数数据；obj：附件的Object类型数据。返回值：从全局的对象池中返回一个Message对象。*/message.what=SHOW_RESPONSE;message.obj=response.toString();//这里是子线程，这个用handler发送信息给主线程handler.sendMessage(message);} catch (Exception e) {// TODO: handle exception}finally{connection.disconnect();}}}).start();Toast.makeText(MainActivity.this, "thread start", Toast.LENGTH_SHORT).show();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}}

本人小白，请大神有错必纠！狠狠鞭策我。。