Android 测试Handler的基本使用

package com.sherlock.app_handler;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.EditText;
import android.widget.ProgressBar;

/***
 * 测试Handler的基本使用
 * @author sherlock
	1. 创建Handler成员变量对象, 并重写其handleMessage()
	2. 在分/主线程创建Message对象
	3. 使用handler对象发送Message
	4. 在handleMessage()中处理消息
 */
public class HandlerTestActivity extends Activity {

	private ProgressBar pb_handler1_loading;
	private EditText et_handler1_result;

	//1. 创建Handler成员变量对象, 并重写其handleMessage()
	private Handler handler = new Handler(){
		public void handleMessage(android.os.Message msg) {//在主线程执行
			if(msg.what == 1) {
				//4. 在handleMessage()中处理消息
				String result = (String) msg.obj;
				et_handler1_result.setText(result);
				pb_handler1_loading.setVisibility(View.INVISIBLE);
			}
		}
	};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_handler_test);

		pb_handler1_loading = (ProgressBar) findViewById(R.id.pb_handler1_loading);
		et_handler1_result = (EditText) findViewById(R.id.et_handler1_result);
	}

	/*
	 1. 主线程, 显示提示视图(ProgressDialog/ProgressBar)
    2. 分线程, 联网请求, 并得到响应数据
    3. 主线程, 显示数据/隐藏提示视图
	 */
	public void getSubmit1(View v) {
		//1. 主线程, 显示提示视图(ProgressDialog/ProgressBar)
		pb_handler1_loading.setVisibility(View.VISIBLE);
		//2. 分线程, 联网请求, 并得到响应数据
		new Thread(){
			public void run() {
				String path = "http://192.168.3.18:8080/SSH/client/json/myFile_search.shtml?name=Tom&age=12";
				try {
					final String result = requestToString(path);

					//3. 主线程, 显示数据
					runOnUiThread(new Runnable() {
						@Override
						public void run() {
							et_handler1_result.setText(result);
							pb_handler1_loading.setVisibility(View.INVISIBLE);
						}
					});
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}.start();
	}

	public void getSubmit2(View v) {
		//1). 主线程, 显示提示视图(ProgressDialog/ProgressBar)
		pb_handler1_loading.setVisibility(View.VISIBLE);
		//2). 分线程, 联网请求, 并得到响应数据
		new Thread(){
			public void run() {
				String path = "http://192.168.3.18:8080/SSH/client/json/myFile_search.shtml?name=Tom&age=12";
				try {
					String result = requestToString(path);

					//3). 主线程, 显示数据
					//2. 在分/主线程创建Message对象
					Message message = Message.obtain();
					message.what = 1;//标识
					message.obj = result;
					//3. 使用handler对象发送Message
					handler.sendMessage(message);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}.start();
	}

	/**
	 * 请求服务器端, 得到返回的结果字符串
	 * @param path  :
	 * @throws Exception
	 */
	public String requestToString(String path) throws Exception {
		URL url = new URL(path);
		HttpURLConnection connection = (HttpURLConnection) url.openConnection();
		connection.setConnectTimeout(5000);
		connection.setReadTimeout(5000);
		connection.connect();
		InputStream is = connection.getInputStream();
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		byte[] buffer = new byte[1024];
		int len = -1;
		while ((len = is.read(buffer)) != -1) {
		baos.write(buffer, 0, len);
		}
		baos.close();
		is.close();
		String result = baos.toString();
		connection.disconnect();

		return result;
	}

}