String url = "http://demo/api/book/";HttpHeaders headers = new HttpHeaders();MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");headers.setContentType(type);String requestJson = "{...}";HttpEntity<String> entity = new HttpEntity<String>(requestJson,headers);String result = restTemplate.postForObject(url, entity, String.class);

上面是针对json格式，然后返回json格式的。

 HttpHeaders requestHeaders = new HttpHeaders();
//        requestHeaders.set("head", "password");requestHeaders.setContentType(MediaType.APPLICATION_JSON);requestHeaders.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));Map<String, Object> m=new HashMap<String, Object>();m.put("shopName", shopName);
//        m.put("red", 3);//通过HttpEntity 设置参数 headHttpEntity<?> request=new HttpEntity(m, requestHeaders);Shop[] shops = restTemplate.postForObject(url + "list", request, Shop[].class);

上面的得修改为

   MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();

不然会报错的。

最后修改为这种格式

 HttpHeaders httpHeaders = new HttpHeaders();
//        httpHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);httpHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();map.add("shopName",shopName);
//        HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(map, httpHeaders);HttpEntity<?> requestEntity=new HttpEntity(map, httpHeaders);Shop[] shops = restTemplate.postForObject(url + "/list", requestEntity, Shop[].class);