使用httpclient提交post请求

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

//使用httpclient提交post请求 x-www-form-urlencoded 
public class PostTest{
 
    public static void main(String[] args) throws Exception {
    String url="http://localhost:8080/boot/user/";
    Map<String,Object> params=new HashMap<String,Object>();
    params.put("a", "1");
    String result=post(url,params);
        System.out.println(result);
    }
    
    public static String post(String url, Map<String,Object> params){
        HttpClient client = HttpClients.createDefault();
        HttpPost hp=new HttpPost(url);
        String s="";
        try {
        List<NameValuePair> names=new ArrayList<NameValuePair>();
        Set<String> keys=params.keySet();
        for(String k:keys) {
        names.add(new BasicNameValuePair(k, params.get(k).toString()));
        }
        hp.setEntity(new UrlEncodedFormEntity(names,"UTF-8"));
        hp.setHeader("Content-type", "application/x-www-form-urlencoded");
        HttpResponse response=client.execute(hp);
        int status=response.getStatusLine().getStatusCode();
        if(status==200) {
        HttpEntity entity=response.getEntity();
        s=EntityUtils.toString(entity);
        }
       
        }catch(Exception e) {
        e.printStackTrace();
        }
        return s;
    } 
}