自己写一个发送http post请求的工具类，因为需要头部和参数，网上没有合适的，拿出来分享下
只需要传三个参数：地址，头部map，bodymap
另外响应已经将body取出并转成字符串返回

maven引入httpClient

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

代码

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

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 org.apache.http.util.EntityUtils;
import org.springframework.stereotype.Component;


public String postMap(String url,Map<String,String> headerMap,Map<String, String> contentMap) {
        String result = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost post = new HttpPost(url);
        List<NameValuePair> content = new ArrayList<NameValuePair>();
        Iterator iterator = contentMap.entrySet().iterator();           //将content生成entity
        while(iterator.hasNext()){  
            Entry<String,String> elem = (Entry<String, String>) iterator.next();  
            content.add(new BasicNameValuePair(elem.getKey(),elem.getValue()));  
        }
        CloseableHttpResponse response = null;
        try {
            Iterator headerIterator = headerMap.entrySet().iterator();          //循环增加header
            while(headerIterator.hasNext()){  
                Entry<String,String> elem = (Entry<String, String>) headerIterator.next();  
                post.addHeader(elem.getKey(),elem.getValue());
            }
            if(content.size() > 0){  
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(content,"UTF-8");  
                post.setEntity(entity);
            }
            response = httpClient.execute(post);            //发送请求并接收返回数据
            if(response != null && response.getStatusLine().getStatusCode() == 200)
            {
                HttpEntity entity = response.getEntity();       //获取response的body部分
                result = EntityUtils.toString(entity);          //读取reponse的body部分并转化成字符串
            }
            return result;
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                httpClient.close();
                if(response != null)
                {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        return null;
    }