自定义HttpMessageConverter

阳光穿透心脏的1/2处 2022-06-13 08:07 250阅读 0赞

HttpMessageConverter是用来处理request和response里的数据的，我们可以自定义，用于类型转换。

自定义对象和字符串之间的转换：

public class MyMessageConverter extends AbstractHttpMessageConverter<DemoObj> {
        public MyMessageConverter(){
            //设置我们新定义的媒体类型为application/x-wisely
            super(new MediaType("application","x-wisely", Charset.forName("UTF-8")));
        }
        //标明本HttpMessageConverter只处理DemoObj这个类
        @Override
        protected boolean supports(Class<?> aClass) {
            return DemoObj.class.isAssignableFrom(aClass);
        }
        //把中间用-隔开的数据转成DemoObj对象
        @Override
        protected DemoObj readInternal(Class<? extends DemoObj> aClass, HttpInputMessage httpInputMessage) throws IOException, HttpMessageNotReadableException {
            String temp= StreamUtils.copyToString(httpInputMessage.getBody(),Charset.forName("UTF-8"));
            String[] tempArr=temp.split("-");
            return new DemoObj(new Long(tempArr[0]),tempArr[1]);
        }
        //把DemoObj对象转化成字符串并输出到response中
        @Override
        protected void writeInternal(DemoObj obj, HttpOutputMessage httpOutputMessage) throws IOException, HttpMessageNotWritableException {
            String out="hello:"+obj.getId()+"-"+obj.getName();
            httpOutputMessage.getBody().write(out.getBytes());
        }
    }

添加自定义converter:

@Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        converters.add(converter());
    }

示例：

@Controller
    public class ConverterController {
        //接收字符串转化为对象，然后把对象又转化为字符串输出。
        @RequestMapping(value="/convert",produces = {
      "application/x-wisely"})
        public @ResponseBody DemoObj convert(@RequestBody DemoObj demoObj){
            return demoObj;
        }
    }

<body>
        <div id="resp"></div><input type="button" οnclick="req();" value="请求"/>
        <script src="assets/js/jquery.js" type="text/javascript"></script>
        <script>
            function req() {
                $.ajax({
                    url:"convert",
                    data:"1-wangyunfei",
                    type:"POST",
                    contentType:"application/x-wisely",
                    success:function (data) {
                        $("#resp").html(data);
                    }
                });
            }
        </script>
    </body>