RestTemplate的异步使用

参考：https://blog.csdn.net/yezhuanxu/article/details/53643248

支持异步调用AsyncRestTemplate

@RequestMapping("/async")
    public String asyncReq(){
        String url = "http://localhost:8080/jsonAsync";
        ListenableFuture<ResponseEntity<JSONObject>> future = asyncRestTemplate.getForEntity(url, JSONObject.class);
        future.addCallback(new SuccessCallback<ResponseEntity<JSONObject>>() {
            public void onSuccess(ResponseEntity<JSONObject> result) {
                System.out.println(result.getBody().toJSONString());
            }
        }, new FailureCallback() {
            public void onFailure(Throwable ex) {
                System.out.println("onFailure:"+ex);
            }
        });
        return "this is async sample";
    }

post请求如何自定义header

@RequestMapping("/headerApi")//模拟远程的restful API
    public JSONObject withHeader(@RequestBody JSONObject parm, HttpServletRequest req){
        System.out.println("headerApi====="+parm.toJSONString());
        Enumeration<String> headers = req.getHeaderNames();
        JSONObject result = new JSONObject();
        while(headers.hasMoreElements()){
            String name = headers.nextElement();
            System.out.println("["+name+"]="+req.getHeader(name));
            result.put(name, req.getHeader(name));
        }
        result.put("descp", "this is from header");
        return result;
    }

    @RequestMapping("/header")
    public Object postWithHeader(){
　　　　//该方法通过restTemplate请求远程restfulAPI
        HttpHeaders headers = new HttpHeaders();
        headers.set("auth_token", "asdfgh");
        headers.set("Other-Header", "othervalue");
        headers.setContentType(MediaType.APPLICATION_JSON);
        
        JSONObject parm = new JSONObject();
        parm.put("parm", "1234");
        HttpEntity<JSONObject> entity = new HttpEntity<JSONObject>(parm, headers);
        HttpEntity<String> response = restTemplate.exchange(
                "http://localhost:8080/headerApi", HttpMethod.POST, entity, String.class);//这里放JSONObject, String 都可以。因为JSONObject返回的时候其实也就是string
        return response.getBody();
    }