RestTemplate异常no suitable HttpMessageConverter found for request type [java.lang.Integer]

package com.chelizi.xiruo.xframework.util;

import net.sf.json.JSONObject;
import org.springframework.http.*;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.oauth2.provider.authentication.OAuth2AuthenticationDetails;
import org.springframework.web.client.DefaultResponseErrorHandler;
import org.springframework.web.client.RestTemplate;

import java.util.Arrays;
import java.util.Map;
import java.util.Set;

/**
* RestTemplate请求工具类
* Created by huangbaidong
* 2017/10/22.
*/
public class RestTemplateRequestUtil {

/**
* GET请求
* @param url
* @param params
* @param clazz
* @param <T>
* @return
*/
public static <T> T getRequest(String url, Map<String, Object> params, Class<T> clazz) {
return request(url, params, clazz, HttpMethod.GET);
}

/**
* POST请求
* @param url
* @param params
* @param clazz
* @param <T>
* @return
*/
public static <T> T postRequest(String url, Map<String, Object> params, Class<T> clazz) {
return request(url, params, clazz, HttpMethod.POST);
}

/**
* restTemplate请求,
* 默认设置了连接超时，请求超时时间
* @param url 请求地址
* @param params 请求参数
* @param clazz  返回结果类型
* @param <T>
* @return
*/
public static <T> T request(String url, Map<String, Object> params, Class<T> clazz, HttpMethod method) {
return request(url, params, clazz, method,30000, 20000);
}

/**
* restTemplate请求
* @param url 请求地址
* @param params 请求参数
* @param clazz  返回结果类型
* @param readTimeout     请求响应超时时间
* @param connectTimeout  连接超时时间
* @param <T>
* @return
*/
public static <T> T request(String url, Map<String, Object> params, Class<T> clazz,
HttpMethod method,int readTimeout, int connectTimeout) {

RestTemplate restTemplate = new RestTemplate();

//设置连接参数
SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
requestFactory.setReadTimeout(readTimeout);
requestFactory.setConnectTimeout(connectTimeout);
restTemplate.setRequestFactory(requestFactory);
restTemplate.setErrorHandler(new DefaultResponseErrorHandler());

//拿到access_toeken
OAuth2AuthenticationDetails details = (OAuth2AuthenticationDetails) SecurityContextHolder.getContext().getAuthentication().getDetails();

//请求头
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
headers.add("Authorization", "bearer "+details.getTokenValue());

//发起请求
ResponseEntity<T> responseEntity = null;
if(HttpMethod.POST.equals(method)) {
JSONObject jsonParams = JSONObject.fromObject(params);
HttpEntity<JSONObject> requestEntity = new HttpEntity<JSONObject>(jsonParams, headers);
responseEntity = restTemplate.exchange(url, method, requestEntity, clazz);
} else {
HttpEntity requestEntity = new HttpEntity(null, headers);
responseEntity = restTemplate.exchange(appendParams(url, params.keySet()), method, requestEntity, clazz, params);
}
return responseEntity.getBody();
}

/**
* 将参数追加到URL后边
* @param url
* @param keys
* @return
* @author: huangbaidong
* @Description: TODO
* @return: String
*/
private static String appendParams(String url, Set<?> keys) {
StringBuilder sb = new StringBuilder(url);
if(url.contains("?")) {
sb.append("&");
} else {
sb.append("?");
}
for (Object key : keys) {
sb.append(key).append("=").append("{").append(key).append("}").append("&");
}
return sb.deleteCharAt(sb.length() - 1).toString();
}

}