Httpclient4.0 功能封装

http://hc.apache.org/httpcomponents-client/examples.html

http://www.iteye.com/topic/192393

4.0中HttpClient不再是一个类，而是一个接口了，

4.0跟3.X的版本相比， 不但底层做了修改，高层架构也做了调整。 并且在Android项目中应用到了4.0， 应该比之前的版本更加稳定。

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package org.apache.http.examples.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

/**
 * 第二个例子 This example demonstrates the recommended way of using API to make sure
 * the underlying connection gets released back to the connection manager.
 */
public class ClientConnectionRelease {

	public final static void main(String[] args) throws Exception {
		HttpClient httpclient = new DefaultHttpClient();

		HttpGet httpget = new HttpGet("http://www.apache.org/");
		HttpResponse response = httpclient.execute(httpget);
		
		HttpEntity entity = response.getEntity();
		try {
			StringBuffer sb = processEntity(entity);
			System.out.println(sb);
		} catch (RuntimeException ex) {
			httpget.abort();
			throw ex;

		}
		httpclient.getConnectionManager().shutdown();
	}

	/**
	 * 处理一个实体
	 * @param entity
	 */
	private static StringBuffer processEntity(HttpEntity entity) 
	{
		StringBuffer sb = new StringBuffer();
		InputStreamReader iReader = null;
		try {
		        InputStream inputStream = entity.getContent();
			iReader = new InputStreamReader(inputStream);
			BufferedReader reader = new BufferedReader(iReader);
			String line = null;
			// 用reader.ready()是不行的
			while ((line = reader.readLine()) != null) {
			sb.append(line + "\r\n");
			}
		      } 
                      catch (Exception ex) {
			    ex.printStackTrace();
		      } finally 
                       {
				try {
					iReader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return sb;
		}

}