HttpClient 工具类

pom.xml加入jar包

	org.apache.httpcomponents
	httpclient
	4.5.2

package com.jk.songxj.utils;

import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
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.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
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.alibaba.fastjson.JSON;

/**
 * 
 * 类: HttpClient 

 * 描述: httpclient工具类 

 * 作者: song

 * 时间: 2017年7月21日 下午3:15:27
 */
public class HttpClientUtil {
	
	static CloseableHttpClient client = null;
	static {
		client = HttpClients.createDefault();
	}
	
	/**
	 * 
	 * 方法: get 

	 * 描述: get请求 

	 * 作者: song

	 * 时间: 2017年7月21日 下午3:15:25
	 * @param url
	 * @param params
	 * @return
	 * @throws Exceptionm
	 */
	public static String get(String url,HashMap params) throws Exception {
		HttpGet httpGet = new HttpGet();
		Set keySet = params.keySet();
		StringBuffer stringBuffer = new StringBuffer();
		stringBuffer.append(url).append("?t=").append(System.currentTimeMillis());
		for (String key : keySet) {
			stringBuffer.append("&").append(key).append("=").append(params.get(key));
		}
		httpGet.setURI(new URI(stringBuffer.toString()));
		CloseableHttpResponse execute = client.execute(httpGet);
		int statusCode = execute.getStatusLine().getStatusCode();
		if (200 != statusCode) {
			return "";
		}
		return EntityUtils.toString(execute.getEntity(), "utf-8");
	}
	
	/**
	 * 
	 * 方法: get2 

	 * 描述: 斜杠传参 

	 * 时间: 2019年7月10日 下午3:29:01
	 * @param url
	 * @param params
	 * @return
	 * @throws Exception
	 */
	public static String get2(String url,String params) throws Exception {
		HttpGet httpGet = new HttpGet();
		StringBuffer stringBuffer = new StringBuffer();
		stringBuffer.append(url).append("/").append(params);
		httpGet.setURI(new URI(stringBuffer.toString()));
		CloseableHttpResponse execute = client.execute(httpGet);
		int statusCode = execute.getStatusLine().getStatusCode();
		if (200 != statusCode) {
			return "";
		}
		return EntityUtils.toString(execute.getEntity(), "utf-8");
	}
	/**
	 * 
	 * 方法: post 

	 * 描述: post请求 

	 * 作者: song

	 * 时间: 2017年7月21日 下午3:20:31
	 * @param url
	 * @param params
	 * @return
	 * @throws Exception
	 */
	public static String post(String url,HashMap params) throws Exception {
		HttpPost httpPost = new HttpPost();
		httpPost.setURI(new URI(url));
		List parameters = new ArrayList();
		Set keySet = params.keySet();
		for (String key : keySet) {
			NameValuePair e = new BasicNameValuePair(key, params.get(key).toString());
			parameters.add(e);
		}
		HttpEntity entity = new UrlEncodedFormEntity(parameters , "utf-8");
		httpPost.setEntity(entity );
		CloseableHttpResponse execute = client.execute(httpPost);
		int statusCode = execute.getStatusLine().getStatusCode();
		if (200 != statusCode) {
			return "";
		}
		return EntityUtils.toString(execute.getEntity(), "utf-8");
	}
	/**
	 * 
	 * 方法: post 

	 * 时间: 2019年7月10日 下午3:29:21
	 * @param url
	 * @param params
	 * @param headers
	 * @return
	 * @throws Exception
	 */
	public static String post(String url,HashMap params,HashMap headers) throws Exception {
		HttpPost httpPost = new HttpPost();
		Set keySet2 = headers.keySet();
		Iterator iterator = keySet2.iterator();
		while (iterator.hasNext()) {
			String key = iterator.next();
			String value = headers.get(key).toString();
			httpPost.addHeader(key, value);
		}
	
		httpPost.setURI(new URI(url));
		List parameters = new ArrayList();
		Set keySet = params.keySet();
		for (String key : keySet) {
			NameValuePair e = new BasicNameValuePair(key, params.get(key).toString());
			parameters.add(e);
		}
		HttpEntity entity = new UrlEncodedFormEntity(parameters , "utf-8");
		httpPost.setEntity(entity );
		CloseableHttpResponse execute = client.execute(httpPost);
		int statusCode = execute.getStatusLine().getStatusCode();
		if (200 != statusCode) {
			return "";
		}
		return EntityUtils.toString(execute.getEntity(), "utf-8");
	}
	
	/**
	 * 请求参数为json字符串
	 * @param url
	 * @param params
	 * @return
	 * @throws Exception
	 */
	public static String postJson(String url,HashMap params) throws Exception {
		HttpPost httpPost = new HttpPost();
		httpPost.setURI(new URI(url));
		String jsonString = JSON.toJSONString(params);
		StringEntity stringEntity = new StringEntity(jsonString,"utf-8");
		stringEntity.setContentEncoding("UTF-8");
		stringEntity.setContentType("application/json");//发送json数据需要设置contentType
		httpPost.setEntity(stringEntity);
		CloseableHttpResponse execute = client.execute(httpPost);
		int statusCode = execute.getStatusLine().getStatusCode();
		if (200 != statusCode) {
			System.out.println(execute.getEntity());
			return "";
		}
		return EntityUtils.toString(execute.getEntity(), "utf-8");
	}
	/**
	 * postJson使用示例代码
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		String url = "http://localhost:8081/express/findProductList.do";
		HashMap params = new HashMap();
		HashMap searchinfo = new HashMap();
		searchinfo.put("productType", "手机测试");
		params.put("searchinfo", searchinfo);
		params.put("page", 2);
		
		String postJson = HttpClientUtil.postJson(url , params );
		System.out.println(postJson);
	}
}