HttpClient

1、引入依赖

<!-- httpclient -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.2</version>
</dependency>

2、写工具类

package com.caad.clean.common.util;

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
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 org.apache.http.util.EntityUtils;

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

public class HttpClientUtil {
    private RequestConfig requestConfig = RequestConfig
            .custom()
            .setSocketTimeout(5000)
            .setConnectTimeout(5000)
            .setConnectionRequestTimeout(5000)
            .build();

    private static HttpClientUtil instance = new HttpClientUtil();

    private HttpClientUtil(){
    }

    public static HttpClientUtil getInstance(){
        return instance;
    }

    public String post(String url){
        HttpPost httpPost = new HttpPost(url);
        httpPost.setConfig(requestConfig);
        return httpPost(httpPost);
    }

    public String post(String url, Map<String, String> map){
        HttpPost httpPost = new HttpPost(url);
        httpPost.setConfig(requestConfig);

        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        for (Map.Entry<String, String> entry: map.entrySet()) {
            nameValuePairs.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
        }
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return httpPost(httpPost);
    }

    private String httpPost(HttpPost httpPost){
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;
        String responseContent = "";
        try {
            httpClient = HttpClients.createDefault();
            response = httpClient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            responseContent = EntityUtils.toString(entity, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if(response != null){
                    response.close();
                }
                if(httpClient != null){
                    httpClient.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseContent;
    }
}