HttpClient 发送Post,Get请求例子（包含设置请求头信息和获取返回头信息）

package com.test.action;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

/**
 * 
 * 依赖 commons-httpclient-3.1.jar  commons-codec-1.4.jar 
 * @author tianjun
 * 
 */
public class PostTest
{
	public static void main(String[] args)
	{
		// （1）构造HttpClient的实例
		HttpClient httpClient = new HttpClient();

		// （2）创建POST方法的实例
		PostMethod postMethod = new PostMethod(
				"http://localhost:8080/b/test1.do");
		// GetMethod getMethod = new
		// GetMethod("http://localhost:8080/b/test1.do");

		// （3）设置http request头
		List<Header> headers = new ArrayList<Header>();
		headers.add(new Header("tianjun_key", "tianjun_value"));
		httpClient.getHostConfiguration().getParams().setParameter(
				"http.default-headers", headers);

		// 使用系统提供的默认的恢复策略
		postMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
				new DefaultHttpMethodRetryHandler());
		// getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
		// new DefaultHttpMethodRetryHandler());

		try
		{
			// （4）执行postMethod
			int statusCode = httpClient.executeMethod(postMethod);
			if (statusCode != HttpStatus.SC_OK)
			{
				System.err.println("Method failed: "
						+ postMethod.getStatusLine());
			}

			// （5）读取response头信息
			Header headerResponse = postMethod
					.getResponseHeader("response_key");
			String headerStr = headerResponse.getValue();
			// （6）读取内容
			byte[] responseBody = postMethod.getResponseBody();
			// （7） 处理内容
			System.out.println(headerStr);
			System.out.println(new String(responseBody));
		} catch (HttpException e)
		{
			// 发生致命的异常，可能是协议不对或者返回的内容有问题
			System.out.println("Please check your provided http address!");
			e.printStackTrace();
		} catch (IOException e)
		{
			e.printStackTrace();
		} catch (Exception e)
		{
			e.printStackTrace();
		} finally
		{
			// 释放连接
			postMethod.releaseConnection();
		}
	}
}