【笑小枫的SpringBoot系列】【四】SpringBoot返回统一结果包装

package com.maple.demo.controller;
import com.maple.demo.util.ResultJson;
import lombok.Data;
import lombok.RequiredArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * @author 笑小枫
 * @date 2022/07/15
 */
@RestController
@RequiredArgsConstructor
@RequestMapping("/example")
public class TestResultController {
    @GetMapping("/testResult")
    public Test testResult() {
        Test test = new Test();
        test.setName("笑小枫");
        test.setAge(18);
        test.setRemark("大家好，我是笑小枫，喜欢我的小伙伴点个赞呗");
        return test;
    }
    @GetMapping("/testResultJson")
    public ResultJson testResultJson() {
        Test test = new Test();
        test.setName("笑小枫");
        test.setAge(18);
        test.setRemark("大家好，我是笑小枫，喜欢我的小伙伴点个赞呗");
        return new ResultJson(test);
    }
    @Data
    static class Test {
        private String name;
        private Integer age;
        private String remark;
    }
}

package com.maple.demo.controller;
import com.maple.demo.util.ResultJson;
import lombok.Data;
import lombok.RequiredArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * @author 笑小枫
 * @date 2022/07/15
 */
@RestController
@RequiredArgsConstructor
@RequestMapping("/example")
public class TestResultController {
    @GetMapping("/testResult")
    public Test testResult() {
        Test test = new Test();
        test.setName("笑小枫");
        test.setAge(18);
        test.setRemark("大家好，我是笑小枫，喜欢我的小伙伴点个赞呗");
        return test;
    }
    /**
     * 普通的返回
     */
    @GetMapping("/testResultJson")
    public ResultJson testResultJson() {
        Test test = new Test();
        test.setName("笑小枫");
        test.setAge(18);
        test.setRemark("大家好，我是笑小枫，喜欢我的小伙伴点个赞呗");
        return new ResultJson(test);
    }
    @Data
    static class Test {
        private String name;
        private Integer age;
        private String remark;
    }
}

package com.maple.demo.config;
import com.alibaba.fastjson.JSON;
import com.maple.demo.util.ResultJson;
import lombok.extern.slf4j.Slf4j;
import org.jetbrains.annotations.NotNull;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
/**
 * 对返回结果统一进行处理，包括返回结果格式统一包装，返回异常统一处理
 *
 * @author 笑小枫
 * @date 2022/07/15
 */
@Slf4j
@RestControllerAdvice
public class RestResponseAdvice implements ResponseBodyAdvice<Object> {
    @Override
    public boolean supports(@NotNull MethodParameter returnType,
                            @NotNull Class<? extends HttpMessageConverter<?>> converterType) {
        return true;
    }
    /**
     * 返回结果包装统一返回格式
     *
     * @return 包装后的返回结果
     */
    @Override
    public Object beforeBodyWrite(Object body,
                                  @NotNull MethodParameter returnType,
                                  @NotNull MediaType selectedContentType,
                                  @NotNull Class<? extends HttpMessageConverter<?>> selectedConverterType,
                                  @NotNull ServerHttpRequest request,
                                  ServerHttpResponse response) {
        // 指定返回的结果为application/json格式
        // 不指定，String类型转json后返回Content-Type是text/plain;charset=UTF-8
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        ResultJson result = new ResultJson(body);
        // 若返回类型是ResultJson，则不进行修改
        if (body == null) {
            if (returnType.getParameterType().isAssignableFrom(String.class)) {
                return JSON.toJSONString(result);
            }
        } else if (body instanceof ResultJson) {
            return body;
        } else if (body instanceof String) {
            return JSON.toJSONString(result);
        }
        return result;
    }
}