HttpClient4.X发送带参数的POST请求「建议收藏」

大家好，又见面了，我是你们的朋友全栈君。

HttpClient 是apache 组织下面的一个用于处理HTTP 请求和响应的开源工具。所用jar包为httpclient-4.3.6.jar、httpcore-4.3.3.jar、httpmime-4.3.6.jar、commons-codec-1.6.jar。

发送Post请求代码如下：

package com.zkn.newlearn.httpclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;

import com.google.common.collect.Lists;

/**
 * 
 * @author zkn 2016-06-05
 *
 */
public class HttpClientTest01 {   

	public static void main(String[] args) {
		//创建HttpClient对象
		CloseableHttpClient closeHttpClient = HttpClients.createDefault();
		CloseableHttpResponse httpResponse = null;
		//发送Post请求
		HttpPost httpPost = new HttpPost("http://localhost:8080/MyWebxTest/getCityByProvinceEname.do");
		//设置Post参数
		List<NameValuePair> params = Lists.newArrayList();
		params.add(new BasicNameValuePair("cityEname", "henan"));
		try {
			//转换参数并设置编码格式
			httpPost.setEntity(new UrlEncodedFormEntity(params,Consts.UTF_8));
			//执行Post请求 得到Response对象
			httpResponse = closeHttpClient.execute(httpPost);
			//httpResponse.getStatusLine() 响应头信息
			System.out.println(httpResponse.getStatusLine());
			//返回对象 向上造型
			HttpEntity httpEntity = httpResponse.getEntity();
			if(httpEntity != null){
				//响应输入流
				InputStream is = httpEntity.getContent();
				//转换为字符输入流
				BufferedReader br = new BufferedReader(new InputStreamReader(is,Consts.UTF_8));
				String line = null;
				while((line=br.readLine())!=null){
					System.out.println(line);
				}
				//关闭输入流
				is.close();
			}
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (ClientProtocolException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			if(httpResponse != null){
				try {
					httpResponse.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if(closeHttpClient != null){
				try {
					closeHttpClient.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
}