Spring之RequestBodyAdvice和ResponseBodyAdvice使用场景和原理

在实际项目中，我们常常需要在Controller请求前后进行一些操作，比如：参数解密/返回结果加密，打印请求参数和返回结果的日志等。

1. 通常返回结果包含code、message、data，结构如下
2. 缺点：每个Controller都要修改

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class ResponseResult {
    private int code;
    private String message;
    private T data;
    public ResponseResult(T data) {
        this.data = data;
        this.code = 0;
        this.message = "success";
    }
}

基于ControllerAdvice和HttpMessageConverter实现

注解1：标记不加密处理ExcludeHttpBodyDecrypt

import java.lang.annotation.*;


@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExcludeHttpBodyDecrypt {

}

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;


@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HttpBodyDecrypt {
}

@RestController
@RequestMapping("/UniversityManagement")
public class BsBuUniversityInfoController {
    @HttpBodyDecrypt
    @PostMapping(value = "/BsBuUniversityInfo/testNoLogin", name = "测试接口")
    public Object test(@RequestBody BsBuUniversityInfoModel model) {
        BsBuUniversityInfo buUniversityInfo = new BsBuUniversityInfo();
        buUniversityInfo.setUniversityCode("00000");
        return buUniversityInfo;
    }
}

import cn.gewut.business.common.Annotation.ExcludeHttpBodyDecrypt;
import cn.gewut.business.common.Annotation.HttpBodyDecrypt;
import cn.gewut.business.common.Util.AESUtils;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;

@ControllerAdvice
public class RequestAdvisor implements RequestBodyAdvice {

    @Override
    public boolean supports(MethodParameter methodParameter, Type targetType, Class> converterType) {
        System.out.println("supports");
        //排除解密注解--包含@ExcludeHttpBodyDecrypt 返回false不执行
        boolean methodHasExcludeHttpBodyDecrypt = methodParameter.hasMethodAnnotation(ExcludeHttpBodyDecrypt.class);
        if (methodHasExcludeHttpBodyDecrypt) {
            return false;
        }
        //解密注解--包含@HttpBodyDecrypt 返回true 需要执行
        boolean methodHasHttpBodyDecrypt = methodParameter.hasMethodAnnotation(HttpBodyDecrypt.class);
        if (methodHasHttpBodyDecrypt) {
            return true;
        }
        //排除解密注解--声明类是否包含@ExcludeHttpBodyDecrypt 返回false不执行
        boolean classHasExcludeHttpBodyDecrypt = methodParameter.getDeclaringClass().getAnnotation(ExcludeHttpBodyDecrypt.class) != null;
        if (classHasExcludeHttpBodyDecrypt) {
            return false;
        }
        boolean classHasHttpBodyDecrypt = methodParameter.getDeclaringClass().getAnnotation(HttpBodyDecrypt.class) != null;
        if (classHasHttpBodyDecrypt) {
            return true;
        }
        return false;
    }

    @Override
    public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class> converterType) throws IOException {
        System.out.println("beforeBodyRead");

        if (inputMessage.getBody().available() <= 0) {
            return inputMessage;
        }
        byte[] requestDataByte = new byte[inputMessage.getBody().available()];
        inputMessage.getBody().read(requestDataByte);
        byte[] requestDataByteNew = null;
        try {
            // 解密
            requestDataByteNew  = AESUtils.decryptHandler(requestDataByte);
        } catch (Exception e) {
            e.printStackTrace();
        }
        // 使用解密后的数据，构造新的读取流
        InputStream rawInputStream = new ByteArrayInputStream(requestDataByteNew);
        return new HttpInputMessage() {
            @Override
            public HttpHeaders getHeaders() {
                return inputMessage.getHeaders();
            }

            @Override
            public InputStream getBody() throws IOException {
                return rawInputStream;
            }
        };
    }

    @Override
    public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class> converterType) {
        System.out.println("afterBodyRead");
        return body;
    }

    @Override
    public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class> converterType) {
        System.out.println("handleEmptyBody");
        return null;
    }

}

import cn.gewut.business.common.Util.ResponseResult;
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.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

@ControllerAdvice
public class ResponseAdvisor implements ResponseBodyAdvice