SpringMVC/SpringBoot--获取参数/传参--方法/实例

àì夳堔傛蜴生んèń 2022-09-15 05:47 340阅读 0赞

原文网址：[SpringMVC/SpringBoot--获取参数/传参--方法/实例\_IT利刃出鞘的博客-CSDN博客][SpringMVC_SpringBoot--_--_IT_-CSDN]

# 简介 #

本文用实例介绍SpringBoot获取前端传参的方法，包括：urlencoded/form-data/body/多个body。

在开发时我们会在Controller获得前端传过来的参数，参数有多种格式，由[Content-Type][]指定，不同的类型有所不同，本文介绍对于不同的类型后端如何接收。

# 创建项目 #

创建SpringBoot项目，引入spring-boot-starter-web

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70][]

# 实体类 #

User.java

package com.example.demo.entity;
    
    import java.util.List;
    
    public class User {
        private String name;
        private Integer age;
        private String[] password;
        private List<Integer> scoreArray;
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String[] getPassword() {
            return password;
        }
    
        public void setPassword(String[] password) {
            this.password = password;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public List<Integer> getScoreArray() {
            return scoreArray;
        }
    
        public void setScoreArray(List<Integer> scoreArray) {
            this.scoreArray = scoreArray;
        }
    }

Account.java

package com.example.demo.entity;
    
    import java.io.Serializable;
    
    public class Account implements Serializable {
        private String phoneNum;
        private String[] emails;
    
        public String getPhoneNum() {
            return phoneNum;
        }
    
        public void setPhoneNum(String phoneNum) {
            this.phoneNum = phoneNum;
        }
    
        public String[] getEmails() {
            return emails;
        }
    
        public void setEmails(String[] emails) {
            this.emails = emails;
        }
    }

# x-www-form-urlencoded请求 #

## **Controller** ##

BasicController.java

package com.example.demo.controller;
    
    import com.example.demo.entity.User;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import java.util.Arrays;
    import java.util.List;
    
    // localhost:8080/basic/no_annotation/string1
    @RequestMapping("/basic")
    @Controller
    public class BasicController {
        @RequestMapping("/1")
        @ResponseBody
        public String test1(int intVal, Long longVal, String myStr){
            System.out.println("intVal  : " + intVal);
            System.out.println("longVal : " + longVal);
            System.out.println("myStr   : " + myStr);
            return "Hello world";
        }
    
        @RequestMapping("/2")
        @ResponseBody
        public User test2(@RequestParam Integer intVal,
                                             @RequestParam(value = "my_str", required = false) String[] myStr,
                                             @RequestParam String[] password,
                                             @RequestParam List<Integer> scoreArray,
                                             @RequestParam Integer age,
                                             User user){
            System.out.println("intVal     : " + intVal);
            System.out.println("age        : " + age);
            System.out.println("myStr      : " + Arrays.asList(myStr));
            System.out.println("password   : " + Arrays.asList(password));
            System.out.println("scoreArray : " + scoreArray);
    
            return user;
        }
    
        @RequestMapping("/3")
        @ResponseBody
        public User test3(@RequestBody User user){
            return user;
        }
    }

## 测试 ##

**测试1：基本类型为空导致错误**

[http://localhost:8080/basic/1][http_localhost_8080_basic_1]

后端打印

java.lang.IllegalStateException: Optional int parameter 'intVal' is present but cannot be translated into a null value due to being declared as a primitive type. Consider declaring it as object wrapper for the corresponding primitive type.

前端结果

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 1][]

**测试2**：**正常操作**（其实也不正常，最好不要用基本类型接收。）

[http://localhost:8080/basic/1?intVal=2&myStr=hehe][http_localhost_8080_basic_1_intVal_2_myStr_hehe]

后端

intVal  : 2
    longVal : null
    myStr   : hehe

前端

![20200703202522251.png][]

**测试3**：**正常操作**

[http://localhost:8080/basic/2?intVal=2&my\_str=Tony,Stark&name=Jarvis&age=21&password=ab,cd&scoreArray=99,98&phoneNum=12][http_localhost_8080_basic_2_intVal_2_my_str_Tony_Stark_name_Jarvis_age_21_password_ab_cd_scoreArray_99_98_phoneNum_12]

后端

intVal     : 2
    age        : 21
    myStr      : [Tony, Stark]
    password   : [ab, cd]
    scoreArray : [99, 98]

前端

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 2][]

**结论**

*  如果一个参数，实体类与接口参数都有，则都会赋值。
 *  若实体类中有数组/List 成员，也会对它直接赋值。
 *  若实体类含有实体类，无法赋值。因为参数中没有与实体类相同名字的key，此时就要用form-data或者json了。（或者x-www-urlencoded也有写类参数的方法，目前不知道）

**测试4**：**@RequestParam缺少参数访问（失败）**

[http://localhost:8080/basic/2?intVal=2&my\_str=Tony,Stark&name=Jarvis&age=21&password=ab,cd&phoneNum=12][http_localhost_8080_basic_2_intVal_2_my_str_Tony_Stark_name_Jarvis_age_21_password_ab_cd_scoreArray_99_98_phoneNum_12]

后端

2020-07-04 18:00:37.222  WARN 15844 --- [nio-8080-exec-8] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.bind.MissingServletRequestParameterException: Required List parameter 'scoreArray' is not present]

前端

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 3][]

**测试5**：**用@RequestBody接收（失败）**

[http://localhost:8080/basic/3?intVal=2&my\_str=Tony,Stark&name=Jarvis&age=21&password=ab,cd&scoreArray=99,98&phoneNum=12][http_localhost_8080_basic_3_intVal_2_my_str_Tony_Stark_name_Jarvis_age_21_password_ab_cd_scoreArray_99_98_phoneNum_12]

后端

2020-07-04 14:02:55.954  WARN 15844 --- [nio-8080-exec-3] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing: public com.example.demo.entity.User com.example.demo.controller.BasicController.test3(com.example.demo.entity.User)]

前端

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 4][]

# form-data请求 #

**其他网址**

[使用FormData格式在前后端传递数据 - wenr - 博客园][FormData_ - wenr -]

## **Controller** ##

**FormDataController.java**

package com.example.demo.controller;
    
    import com.example.demo.entity.User;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.*;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.util.Arrays;
    import java.util.List;
    
    // localhost:8080/basic/no_annotation/string1
    @RequestMapping("/formdata")
    @Controller
    public class FormDataController {
        @RequestMapping("/1")
        @ResponseBody
        public String test1(int intVal, Long longVal, String myStr){
            System.out.println("intVal  : " + intVal);
            System.out.println("longVal : " + longVal);
            System.out.println("myStr   : " + myStr);
            return "Hello world";
        }
    
        @RequestMapping("/2")
        @ResponseBody
        public User test2(@RequestParam Integer intVal,
                         @RequestParam(value = "my_str", required = false) String[] myStr,
                         @RequestParam String[] password,
                         @RequestParam List<Integer> scoreArray,
                         @RequestParam Integer age,
                         User user){
            System.out.println("intVal     : " + intVal);
            System.out.println("age        : " + age);
            System.out.println("myStr      : " + Arrays.asList(myStr));
            System.out.println("password   : " + Arrays.asList(password));
            System.out.println("scoreArray : " + scoreArray);
    
            return user;
        }
    
        @RequestMapping("/3")
        @ResponseBody
        public User test3(User user){
            System.out.println("name            : " + user.getName());
            System.out.println("password        : " + Arrays.asList(user.getPassword()));
            System.out.println("scoreArray      : " + user.getScoreArray());
            System.out.println("acount.phoneNum : " + user.getAccount().getPhoneNum());
            System.out.println("account.emails  : " + Arrays.asList(user.getAccount().getEmails()));
            return user;
        }
    
        @RequestMapping("/4")
        @ResponseBody
        public User test4(@RequestBody User user){
            System.out.println("name            : " + user.getName());
            System.out.println("password        : " + Arrays.asList(user.getPassword()));
            System.out.println("scoreArray      : " + user.getScoreArray());
            System.out.println("acount.phoneNum : " + user.getAccount().getPhoneNum());
            System.out.println("account.emails  : " + Arrays.asList(user.getAccount().getEmails()));
            return user;
        }
    
        @PostMapping(value = "/5", headers="content-type=multipart/form-data")
        @ResponseBody
        public String test5(MultipartFile file1, MultipartFile[] files) {
            return "file1名字：" + file1.getOriginalFilename() + "\r\n"
                    + "files[0]名字：" + files[0].getOriginalFilename() + "\r\n"
                    + "files[1]名字：" + files[1].getOriginalFilename();
        }
    }

## 测试 ##

**测试1：基本类型为空导致错误**

postman（[http://localhost:8080/formdata/1][http_localhost_8080_formdata_1]）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 5][]

后端

**测试2**：**基本类型不为空（成功） //**最好不要用基本类型接收。

postman：访问[http://localhost:8080/formdata/1/][http_localhost_8080_formdata_1 1]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 6][]

后端

intVal  : 2
    longVal : null
    myStr   : hehe

**测试3**：**正常操作：没有@RequestBody的接收单个实体类接收**

postman的body数据

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 7][]

后端

name            : Jarvis
    password        : [ab, cd]
    scoreArray      : [99, 98]
    acount.phoneNum : null
    account.emails  : [123@qq.com, 456@163.com]

**测试4**：**有@RequestBody的接收单个实体类接收（失败）**

postman访问：[http://localhost:8080/formdata/4/][http_localhost_8080_formdata_4]

postman数据：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 8][]

后端打印

2020-07-06 09:18:19.637  WARN 16088 --- [nio-8080-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'multipart/form-data;boundary=--------------------------428878162965035610803450;charset=UTF-8' not supported]

**测试5： 接收单文件与多文件**

postman访问：[http://localhost:8080/formdata/5][http_localhost_8080_formdata_5]

postman数据：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 9][]

# JSON请求（单个对象） #

## **Controller** ##

JsonController.java

package com.example.demo.controller;
    
    import com.example.demo.entity.User;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import java.util.Arrays;
    import java.util.List;
    
    @RequestMapping("/json")
    @Controller
    public class JsonController {
        @RequestMapping("/1")
        @ResponseBody
        public User setUserNoAnnotation(User user, List<String> password, Integer[] scoreArray) {
            printUser(user);
            return user;
        }
    
        @RequestMapping("/2")
        @ResponseBody
        public User setUserAnnotation(@RequestBody User user) {
            printUser(user);
            return user;
        }
    
        @RequestMapping("/3")
        @ResponseBody
        public User setUserAnnotation1(@RequestBody User user, @RequestParam List<String> password, Integer[] scoreArray) {
            System.out.println(password);
            if (scoreArray != null) {
                System.out.println(Arrays.asList(scoreArray));
            } else {
                System.out.println("scoreArray = null");
            }
            System.out.println();
            printUser(user);
    
            return user;
        }
    
        @RequestMapping("/4")
        @ResponseBody
        public User setUserAnnotation2(@RequestBody User user, @RequestBody List<String> password, @RequestBody Integer[] scoreArray) {
            if (password != null) {
                System.out.println(password);
            } else {
                System.out.println("password = null");
            }
    
            if (scoreArray != null) {
                System.out.println(Arrays.asList(scoreArray));
            } else {
                System.out.println("scoreArray = null");
            }
            System.out.println();
            printUser(user);
            return user;
        }
    
        private void printUser(User user){
            System.out.println("name            : " + user.getName());
            System.out.println("password        : " + Arrays.asList(user.getPassword()));
            System.out.println("scoreArray      : " + user.getScoreArray());
            System.out.println("acount.phoneNum : " + user.getAccount().getPhoneNum());
            System.out.println("account.emails  : " + Arrays.asList(user.getAccount().getEmails()));
        }
    }

## 测试 ##

**测试前提**

json的body

{
        "name": "Jarvis",
        "password": [
            "ab",
            "cd"
        ],
        "scoreArray": [
            99,
            98
        ],
        "account": {
            "phoneNum": "123",
            "emails": [
                "123@qq.com",
                "456@163.com"
            ]
        }
    }

**测试1：正常操作**

使用postman，url：[http://localhost:8080/json/2][http_localhost_8080_json_2]

后端

name            : Jarvis
    password        : [ab, cd]
    scoreArray      : [99, 98]
    acount.phoneNum : 123
    account.emails  : [123@qq.com, 456@163.com]

postman

{
        "name": "Jarvis",
        "age": null,
        "password": [
            "ab",
            "cd"
        ],
        "scoreArray": [
            99,
            98
        ],
        "account": {
            "phoneNum": "123",
            "emails": [
                "123@qq.com",
                "456@163.com"
            ]
        }
    }

**测试2：（不使用@RequestBody接收）**

使用postman，url：[http://localhost:8080/json/1][http_localhost_8080_json_1]

后端

2020-07-03 23:27:18.504 ERROR 12568 --- [nio-8080-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: No primary or default constructor found for interface java.util.List] with root cause
    
    java.lang.NoSuchMethodException: java.util.List.<init>()
    	at java.lang.Class.getConstructor0(Class.java:3082) ~[na:1.8.0_51]
    	at java.lang.Class.getDeclaredConstructor(Class.java:2178) ~[na:1.8.0_51]
    	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:85) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:139) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:167) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_51]
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_51]
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.36.jar:9.0.36]
    	at java.lang.Thread.run(Thread.java:745) [na:1.8.0_51]

postman

{
        "timestamp": "2020-07-03T15:44:10.224+00:00",
        "status": 500,
        "error": "Internal Server Error",
        "message": "",
        "path": "/json/1"
    }

**测试3：（一个有@RequestBody+多个无）**

postman访问：[http://localhost:8080/json/3?password=ef,gh][http_localhost_8080_json_3_password_ef_gh]

后端

[ef, gh]
    scoreArray = null
    
    name            : Jarvis
    password        : [ab, cd]
    scoreArray      : [99, 98]
    acount.phoneNum : 123
    account.emails  : [123@qq.com, 456@163.com]

postman

**测试4：多个@RequestBody**

postman访问：[http://localhost:8080/json/4?password=ef,gh][http_localhost_8080_json_4_password_ef_gh]

后端

2020-07-03 23:48:06.907  WARN 2644 --- [nio-8080-exec-5] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: I/O error while reading input message; nested exception is java.io.IOException: Stream closed]

postman

{
        "timestamp": "2020-07-03T15:47:45.924+00:00",
        "status": 400,
        "error": "Bad Request",
        "message": "",
        "path": "/json/4"
    }

**错误原因**

其他网址：[I/O error while reading input message; nested exception is java.io.IOException: Stream closed | 易学教程][I_O error while reading input message_ nested exception is java.io.IOException_ Stream closed _]

每个方法只能有一个@RequestBody。使用@RequestBody把请求转化为特定的Object（在最后会关闭相应的流），所以在同一个方法中第二次使用@RequestBody是没用的，因为流已经关闭。

You cannot use it this way as only one @RequestBody per method is allowed. Using @RequestBody Spring converts incoming request body into the specified object (what closes the stream representing body at the end) so attempting to use @RequestBody second time in the same method makes no sense as stream has been already closed.

# JSON请求（多个对象） #

**其他网址**

[SpringMVC接收多个对象参数\_木子叶的奔跑-CSDN博客\_spring接收2个对象的参数][SpringMVC_-CSDN_spring_2]

## **方案1：**Map对象接收 ##

**前端**

$("#ok2").click(function(){
       var json = {"user":{"id":9527,"userName":"zcy","realName":"钢铁侠"},"info":{"id":998,"address":"纽约"}};
       $.ajax({
           url:"http://localhost:8080/more/show",
           type:"post",
           cache:false,
           contentType:"application/json",
           data:JSON.stringify(json),
           success:function(data){
               alert(data);                          
           }
       });
    });

**后端**

@RequestMapping(value = "/show")
    public String test(@RequestBody  Map<String,Object> map){
    
        // 拿到Object之后 再做转换为实体即可 可以用FastJson
        Object user = map.get("user");
        Object info = map.get("info");
    
        return "success";
    }

## 方案2：自定义处理方法 ##

**前端**

$("#ok2").click(function(){
       var json = {"user":{"id":9527,"userName":"zcy","realName":"钢铁侠"},"info":{"id":998,"address":"纽约"}};
       $.ajax({
           url:"http://localhost:8080/more/custom",
           type:"post",
           cache:false,
           // 直接传josn对象 这里与上文不同
           data:json,
           success:function(data){
               alert(data);                          
           }
       });
    });

**后端**

自定义注解 （加在控制器的参数前作为标记）

@Target(ElementType.PARAMETER)
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public @interface JsonObject {
    }

自定义处理类（实现HandlerMethodArgumentResolver接口）

public class JsonObjectArgResolverHandler implements HandlerMethodArgumentResolver {
     
        @Override
        public boolean supportsParameter(MethodParameter methodParameter) {
            return methodParameter.hasParameterAnnotation(JsonObject.class);
        }
     
        @Override
        public Object resolveArgument(MethodParameter methodParameter,
                                      ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest,
                                      WebDataBinderFactory webDataBinderFactory) throws Exception {
     
            // 获取Controller中的参数名
            String name = methodParameter.getParameterName();
            // 获取Controller中参数的类型
            Class clazz = methodParameter.getParameterType();
            Object arg = null;
            // 获取该参数实体的所用属性
            Field[] fields = clazz.getDeclaredFields();
            // 实例化
            Object target = clazz.newInstance();
     
            // 创建WebDataBinder对象 反射 遍历fields给属性赋值
            WebDataBinder binder = webDataBinderFactory.createBinder(nativeWebRequest,null,name);
            for (Field field:fields){
                field.setAccessible(true);
                String fieldName = field.getName();
                Class<?> fieldType = field.getType();
                // 在request中 多对象json数据的key被解析为 user[id] user[realName] info[address] 的这种形式
                String value = nativeWebRequest.getParameter(name + "[" + fieldName + "]");
                arg = binder.convertIfNecessary(value,fieldType,methodParameter);
                field.set(target,arg);
            }
     
            return target;
        }
    }

注册自己写的处理类

@Component
    public class MyWebAppConfig implements WebMvcConfigurer {
        @Override
        public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
            // 配置自定义接收参数
            WebMvcConfigurer.super.addArgumentResolvers(resolvers);
            resolvers.add(new JsonObjectArgResolverHandler());
        }
    }

Controller

@RequestMapping(value = "/custom")
    public String custom(@JsonObject User user, @JsonObject Info info){
        System.out.println(user.toString());
        System.out.println(info.toString());
    
        return "success";
    }

[SpringMVC_SpringBoot--_--_IT_-CSDN]: https://knife.blog.csdn.net/article/details/120678261
[Content-Type]: https://knife.blog.csdn.net/article/details/120678449
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[http_localhost_8080_basic_1]: http://localhost:8080/basic/no_annotation/1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 1]: /images/20220828/c41d6db0a3ce40cbb55042f51c85e3e4.png
[http_localhost_8080_basic_1_intVal_2_myStr_hehe]: http://localhost:8080/basic/no_annotation/1?intVal=2&str=hehe
[20200703202522251.png]: /images/20220828/001e3b2e76cf41729fa01c2549ec10a9.png
[http_localhost_8080_basic_2_intVal_2_my_str_Tony_Stark_name_Jarvis_age_21_password_ab_cd_scoreArray_99_98_phoneNum_12]: http://localhost:8080/basic/2?intVal=2&my_str=Tony,Stark&name=Jarvis&age=21&password=ab,cd&scoreArray=99,100,98
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 2]: /images/20220828/c2d5c068dfc040e8938148cb11c5106a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 3]: /images/20220828/8c3cf467ed0a40ec908892fd2a085598.png
[http_localhost_8080_basic_3_intVal_2_my_str_Tony_Stark_name_Jarvis_age_21_password_ab_cd_scoreArray_99_98_phoneNum_12]: http://localhost:8080/basic/3?intVal=2&my_str=Tony,Stark&name=Jarvis&age=21&password=ab,cd&scoreArray=99,98&phoneNum=12
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 4]: /images/20220828/376db92c72e4411bb29b825c25692589.png
[FormData_ - wenr -]: https://www.cnblogs.com/wenruo/p/8625499.html
[http_localhost_8080_formdata_1]: http://localhost:8080/formdata/1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 5]: /images/20220828/83967ceb7cdd4d4abfe1557cde30eea8.png
[http_localhost_8080_formdata_1 1]: http://localhost:8080/formdata/3/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 6]: /images/20220828/6204c139cad9458cb8d0525e06c20df1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 7]: /images/20220828/f9cf6dd2d69c47208d6aa7a1791e2731.png
[http_localhost_8080_formdata_4]: http://localhost:8080/formdata/4/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 8]: /images/20220828/4addaf6b6734448582be9d632150f203.png
[http_localhost_8080_formdata_5]: http://localhost:8080/formdata/5
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaXlpbmcwY2FuZ2xhbmc_size_16_color_FFFFFF_t_70 9]: /images/20220828/eb0940ec0dcd4690974698b7f9623da1.png
[http_localhost_8080_json_2]: http://localhost:8080/json/2
[http_localhost_8080_json_1]: http://localhost:8080/json/1
[http_localhost_8080_json_3_password_ef_gh]: http://localhost:8080/json/3?password=ef,gh
[http_localhost_8080_json_4_password_ef_gh]: http://localhost:8080/json/4?password=ef,gh
[I_O error while reading input message_ nested exception is java.io.IOException_ Stream closed _]: https://www.e-learn.cn/topic/3352427
[SpringMVC_-CSDN_spring_2]: https://blog.csdn.net/dear_little_bear/article/details/104565425