0219 springmvc- interceptors and response to enhanced

Interceptor

Interceptor interceptor synchronous and asynchronous sub-interceptor;

HandlerInterceptor

The method and timing of execution

You can see the original DispathcerServlet determine the timing of the implementation of its three methods;

AsynHandlerInterceptor

See comments, mainly used to clean up the data in a concurrent environment plus clean up the ThreadLocal;

ResponseBodyAdvice

Note the @ResponseBody return value or return ResponseEntity do some processing;

Data conversion will be output before the message is converted into json data converter;

package com.springbootpractice.interceptor.config;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.springbootpractice.interceptor.config.interceptor.MyInterceptor;
import lombok.SneakyThrows;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import java.util.HashMap;
import java.util.Map;

/**
 * 说明：配置拦截器和设置统一返回格式
 * @author carter
 * 创建时间： 2020年02月19日 11:03 下午
 **/
@Configuration
@ControllerAdvice
public class WebConfig implements WebMvcConfigurer, ResponseBodyAdvice {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        HandlerInterceptor myIntercepter = new MyInterceptor() ;
        registry.addInterceptor(myIntercepter).addPathPatterns("/**");
    }

    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return true;
    }

    @SneakyThrows
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {

       Map<String,Object> map = new HashMap();
       map.put("result","true");
       map.put("data",body);
       return new ObjectMapper().writeValueAsString(map);
    }
}

summary

After completing this section, you can learn:

1. How to configure interceptors, each print takes http interface;
2. How to set up a unified interface return form;

Code point I get!

The original is not easy, please indicate the source.