HttpClient4.X发送带参数的Get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Get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.util.List;

import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import com.google.common.collect.Lists;

public class HttpClientTest02 {

	public static void main(String[] args) {
		CloseableHttpClient httpClient = HttpClients.createDefault();
		CloseableHttpResponse response = null;
		InputStream is = null;
		String url = "http://localhost:8080/MyWebxTest/getCityByProvinceEname.do";
		//封装请求参数
		List<NameValuePair> params = Lists.newArrayList();
		params.add(new BasicNameValuePair("cityEname", "henan"));
		String str = "";
		try {
			//转换为键值对
			str = EntityUtils.toString(new UrlEncodedFormEntity(params, Consts.UTF_8));
			System.out.println(str);
			//创建Get请求
			HttpGet httpGet = new HttpGet(url+"?"+str);
			//执行Get请求，
			response = httpClient.execute(httpGet);
			//得到响应体
			HttpEntity entity = response.getEntity();
			if(entity != null){
				is = entity.getContent();
				//转换为字节输入流
				BufferedReader br = new BufferedReader(new InputStreamReader(is, Consts.UTF_8));
				String body = null;
				while((body=br.readLine()) != null){
					System.out.println(body);
				}
			}
		} catch (ParseException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally{
			//关闭输入流，释放资源
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			//消耗实体内容
			if(response != null){
				try {
					response.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			//关闭相应 丢弃http连接
			if(httpClient != null){
				try {
					httpClient.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		
	}
}