一、前言

众所周知，在Spring Boot框架中，Controller层API接口编码获取请求体参数时，在参数上会使用@RequestBody注解；如果一次请求中，请求体参数携带的内容需要用多个参数接收时，能不能多次使用@RequestBody注解呢？

下面我们先测试一下，参考代码：

package com.learn.springboot.controller;

import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class RequestBodyController {

    @Getter
    @Setter
    @ToString
    static class User {
        private Integer age;
        private String name;
    }

    @Getter
    @Setter
    @ToString
    static class Home {
        private String addr;
        private String phone;
    }

    @Getter
    @Setter
    @ToString
    static class Car {
        private String number;
    }

    @RequestMapping("/req/test")
    public String test(@RequestBody User user, @RequestBody Home home, @RequestBody Car car) {
        return new StringBuilder(user.toString()).append("--").append(home.toString()).append("--").append(car.toString()).toString();
    }
}

PostMan进行请求：

服务端后端日志：

由上面的测试代码可以看出，Spring Boot框架原生是不支持多个参数使用@RequestBody注解的，那么要怎么做才能支持呢？

二、Spring Boot支持多个@RequestBody注解接收参数

1. 增加HttpServletRequest对象输入流获取参数逻辑适配器

import cn.hutool.core.io.IoUtil;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

public class MultiRequestBodyWrapper extends HttpServletRequestWrapper {

    private final byte[] paramBody;

    public MultiRequestBodyWrapper(HttpServletRequest request, ServletResponse response) throws IOException {
        super(request);
        request.setCharacterEncoding(StandardCharsets.UTF_8.name());
        response.setCharacterEncoding(StandardCharsets.UTF_8.name());

        paramBody = IoUtil.readBytes(request.getInputStream(), false);
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream bais = new ByteArrayInputStream(paramBody);
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return bais.read();
            }

            @Override
            public int available() throws IOException {
                return paramBody.length;
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {

            }
        };
    }
}

2. 定义请求过滤器，使定义的适配器生效

import org.springframework.http.MediaType;
import org.springframework.util.StringUtils;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

public class MultiRequestBodyFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        ServletRequest requestWrapper = null;
        // 拦截请求格式是JSON格式的报文
        if (request instanceof HttpServletRequest
                && StringUtils.startsWithIgnoreCase(request.getContentType(), MediaType.APPLICATION_JSON_VALUE)) {
            requestWrapper = new MultiRequestBodyWrapper((HttpServletRequest) request, response);
        }
        if (null == requestWrapper) {
            chain.doFilter(request, response);
        } else {
            chain.doFilter(requestWrapper, response);
        }
    }
}

3. 配置过滤器，使自定义Filter生效

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MultiRequestBodyFilterConfig {

    @Bean
    public FilterRegistrationBean multiRequestBodyFilterRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new MultiRequestBodyFilter());
        registration.addUrlPatterns("/req/*");
        registration.setName("multiRequestBodyFilter");
        return registration;
    }

}

4. 重启应用，功能测试

代码：

import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class RequestBodyController {

    @Getter
    @Setter
    @ToString
    static class User {
        private Integer age;
        private String name;
    }

    @Getter
    @Setter
    @ToString
    static class Home {
        private String addr;
        private String phone;
    }

    @Getter
    @Setter
    @ToString
    static class Car {
        private String number;
    }

    @RequestMapping("/req/test")
    public String test(@RequestBody User user, @RequestBody Home home, @RequestBody Car car) {
        return new StringBuilder(user.toString()).append("--").append(home.toString()).append("--").append(car.toString()).toString();
    }
}

PostMan请求：

通过测试结果可以看到，此时多个@RequestBody修饰参数进行请求体接收的功能就实现啦。