HttpClient的get方法请求网络

1.简单介绍一下HttpClient的get方法请求数据

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;

/**
 * 权限 intenet 线程
 * 
 * @author Administrator
 * 
 */
public class MainActivity extends Activity {

	private String tag = "MainActivity-->";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		listView = (ListView) findViewById(R.id.main_list_view);
		bar = (ProgressBar) findViewById(R.id.progress);
		// 从网络请求数据
		getDataFromNet();
	}

	// 从网络请求数据
	private void getDataFromNet() {
		//
		bar.setVisibility(View.VISIBLE);
		// 开启子线程
		new Thread() {
			public void run() {
				/**
				 * HttpClient 1.get,拼接字符串 2.post,通过流进行数据的传输
				 * 
				 */
				// get
				// 1.创建HttpClient对象
				HttpClient client = new DefaultHttpClient();
				// 2.创建请求方法
				HttpGet get = new HttpGet(Url.TOP);
				// 3.执行get请求
				try {
					HttpResponse response = client.execute(get);
					// 取出数据
					StatusLine status = response.getStatusLine();// 状态行
					int code = status.getStatusCode();// 状态码
					if (code == 200) {
						// 取出新闻内容
						HttpEntity entity = response.getEntity();// 实体
						InputStream content = entity.getContent();// 内容
						// 将流--->String
						String json = inputStream2String(content);
						Log.d(tag, "返回结果--》" + json);
						// 解析数据
						ArrayList list = parseJson(json);
						// 发送到主线程（Handler）
						Message message = mHandler.obtainMessage();
						message.obj = list;
						mHandler.sendMessage(message);
					}
				} catch (ClientProtocolException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			};
		}.start();
	}

	// handler
	Handler mHandler = new Handler() {
		public void handleMessage(android.os.Message msg) {
			Log.d(tag, "收到消息");
			// 隐藏进度条
			bar.setVisibility(View.GONE);
			// 接收数据并展示
			ArrayList list = (ArrayList) msg.obj;
			Log.e(tag, "list--->" + list);
			listView.setAdapter(new ArrayAdapter(MainActivity.this,
					android.R.layout.simple_list_item_1, list));
		};
	};
	private ListView listView;
	private ProgressBar bar;

	public String inputStream2String(InputStream content) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		int len = 0;
		byte[] buffer = new byte[1024];
		try {
			while ((len = content.read(buffer)) != -1) {
				os.write(buffer, 0, len);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return os.toString();
	}

	// 解析json数据
	public ArrayList parseJson(String json) {
		ArrayList list = new ArrayList();
		try {
			JSONObject jsonObject = new JSONObject(json);
			JSONObject jsonObject2 = jsonObject.getJSONObject("result");
			JSONArray jsonArray = jsonObject2.getJSONArray("data");
			for (int i = 0; i < jsonArray.length(); i++) {
				list.add(jsonArray.getJSONObject(i).getString("title"));
			}
		} catch (JSONException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		return list;
	}
}