springMVC Controller接收多对象的json数据

转载

小飞侠格鲁帅 2021-08-10 12:12:55 博主文章分类：5小功能

文章标签 json ico ide 自定义 .net 文章分类 Java 后端开发

第一种方法，用包装类封装对象

实体类对象

public class User {
private int id;
private String userName;
private String realName;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getRealName() {
return realName;
}
public void setRealName(String realName) {
this.realName = realName;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", userName='" + userName + '\'' +
", realName='" + realName + '\'' +
'}';
}
}
public class Info {
private int id;
private String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "Info{" +
"id=" + id +
", address='" + address + '\'' +
'}';
}
}
public class RequestParam {
private User user;
private Info info;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public Info getInfo() {
return info;
}
public void setInfo(Info info) {
this.info = info;
}
}

定义了三个实体 RequestParam里面又封装了User类和Info类

JAVA代码

@RequestMapping(value = "/show",method = RequestMethod.POST)
public String show(@RequestBody RequestParam param){
User user = param.getUser();
Info info = param.getInfo();
return user.toString();
}

前台代码

$("#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);
}
});
});

可以成功接收到对象，但是显得没有那么优雅，每次请求数据不同都要另外写一个包装类，显得很麻烦。

第二种方法，用Map对象接收更加简单粗暴

JAVA代码

@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";
}

也不够方便每个对象还要再做一次转换

第三种方法，使用自定义的HandlerMethodArgumentResolver

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";
}

前台代码

$("#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);
}
});
});

第三种方式相对比较好但我有几点还是没明白

public Object resolveArgument(MethodParameter methodParameter,
                              ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest,
                              WebDataBinderFactory webDataBinderFactory)

这个方法中的 ModelAndViewContainer和webDataBinderFactory 这两个对象的作用，怎样写能够优雅，欢迎大家不吝赐教。

                    <li class="tool-item tool-active is-like "><a href='javascript:void(0)'>

第一种方法，用包装类封装对象

实体类对象

public class User {
private int id;
private String userName;
private String realName;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getRealName() {
return realName;
}
public void setRealName(String realName) {
this.realName = realName;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", userName='" + userName + '\'' +
", realName='" + realName + '\'' +
'}';
}
}
public class Info {
private int id;
private String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "Info{" +
"id=" + id +
", address='" + address + '\'' +
'}';
}
}
public class RequestParam {
private User user;
private Info info;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public Info getInfo() {
return info;
}
public void setInfo(Info info) {
this.info = info;
}
}

定义了三个实体 RequestParam里面又封装了User类和Info类

JAVA代码

@RequestMapping(value = "/show",method = RequestMethod.POST)
public String show(@RequestBody RequestParam param){
User user = param.getUser();
Info info = param.getInfo();
return user.toString();
}

前台代码

$("#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);
}
});
});

可以成功接收到对象，但是显得没有那么优雅，每次请求数据不同都要另外写一个包装类，显得很麻烦。

第二种方法，用Map对象接收更加简单粗暴

JAVA代码

@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";
}

也不够方便每个对象还要再做一次转换

第三种方法，使用自定义的HandlerMethodArgumentResolver

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";
}

前台代码

$("#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);
}
});
});

第三种方式相对比较好但我有几点还是没明白

public Object resolveArgument(MethodParameter methodParameter,
                              ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest,
                              WebDataBinderFactory webDataBinderFactory)

这个方法中的 ModelAndViewContainer和webDataBinderFactory 这两个对象的作用，怎样写能够优雅，欢迎大家不吝赐教。

                    <li class="tool-item tool-active is-like "><a href='javascript:void(0)'>

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springMVC Controller接收 多对象的json数据

springMVC Controller接收 多对象的json数据

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springMVC Controller接收多对象的json数据

springMVC Controller接收多对象的json数据