java调用http接口通过RestTemplate调用

package com.ruoyi.common.utils.webservice;

import com.alibaba.fastjson.JSON;
import com.ruoyi.common.utils.StringUtils;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.poi.ss.formula.functions.T;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;

import java.lang.reflect.Field;
import java.util.List;

/***
 @ClassName RestTemplate
 @Author Mr.lyb
 @Date 2020-7-8 16:54  星期三
 ***/
public class RestTemplateUtils {
/***
 * @MethodName: buildParamMaps
 * @Description: 读取要传入的数据
 * @Param: [params]
 * @Return: org.springframework.util.MultiValueMap<java.lang.String,java.lang.String>
 * @Date: 2020-7-8 16:55
   @Author: Mr.lyb   help QQ [email protected]
**/
    public static MultiValueMap<String, String> buildParamMaps(SecurityPlatformParams params){
        Field[] fields = params.getClass().getDeclaredFields();
        if (ArrayUtils.isEmpty(fields)){
            return null;
        }
        MultiValueMap<String, String> paramMap = new LinkedMultiValueMap<>();
        try {
            for (Field field : fields){
                field.setAccessible(true);
                paramMap.add(field.getName(), StringUtils.defaultIfNull(field.get(params), ""));
            }
        }catch (IllegalAccessException e){
            e.printStackTrace();
            return null;
        }
        return paramMap;
    }
/**
 * @MethodName: post
 * @Description: 请求接口返回数据
 * @Param: [restTemplate, url, paramMap]
 * @Return: java.lang.String
 * @Date: 2020-7-8 16:57
   @Author: Mr.lyb
**/
    public static String post(RestTemplate restTemplate, String url, MultiValueMap paramMap) throws Exception{
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
        HttpEntity<MultiValueMap<String, String>> httpEntity = new HttpEntity<>(paramMap, httpHeaders);
        String resultStr;
        try {
            resultStr = restTemplate.postForObject(url, httpEntity, String.class);
        } catch (RestClientException e) {
            throw e;
        }
        return resultStr;
    }


    public static List<T> Entity(RestTemplate restTemplate, String url, MultiValueMap paramMap, Class<?> clazz) throws Exception{
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
        HttpEntity<MultiValueMap<String, String>> httpEntity = new HttpEntity<>(paramMap, httpHeaders);
        String resultStr;
        try {
            resultStr = restTemplate.postForObject(url, httpEntity, String.class);
        } catch (RestClientException e) {
            throw e;
        }

       return (List)JSON.parseArray(resultStr, clazz);

    }

}
//test
 public static void main(String[] args) throws Exception {
        String url="http://localhost:8085/examxx_war/sysDept/yyb";//访问的接口
       RestTemplate restTemplate = new RestTemplate();//模板
       MultiValueMap multiValueMap = null;//定义MultiValueMap对象
       SecurityPlatformParams sp = new SecurityPlatformParams();//这个是对象，里面存放实体类属性用来引用
       sp.setParentId("101");//放入要传入的值，
        MultiValueMap<String, String> stringStringMultiValueMap = RestTemplateUtils.buildParamMaps(sp);//解析
        String post = RestTemplateUtils.post(restTemplate, url, stringStringMultiValueMap);//调用post

        List<SysDept> entity = (List)RestTemplateUtils.Entity(restTemplate, url, stringStringMultiValueMap, SysDept.class);//强转成list对象

       for (SysDept s :entity){
           System.out.println(s.getDeptName());
       }
        System.out.println(entity);

    }

1，返回 json格式

2，返回List集合对象