Spring MVC @RequestBody接收具有非原始属性的Object包装器

Question

我按如下方式创建JSON:

    var manager = {
        username: "admin",
        password: "admin"
    };
    var userToSubscribe = {
        username: "newuser",
        password: "newpassword",
        email: "user@1and1.es"
    };

    var openid = "myopenid";

    var subscription = {
            manager: manager,
            userToSubscribe : userToSubscribe,
            openid : openid
    };

    $.ajax({
        url: '/myapp/rest/subscribeUser.json',
        type: 'POST',
        dataType: 'json',
        contentType: 'application/json',
        mimeType: 'application/json',
        data: JSON.stringify({subscription : subscription})   
    });

这是发送的JSON:

{"subscription":{"manager":{"username":"admin","password":"admin"},"userToSubscribe":{"username":"newuser","password":"newpassword","email":"user@1and1.es"},"openid":"myopenid"}}  

我想将这个JSON映射到Wrapper类.这是包装器:

private class Subscription{
    private User manager;
    private User userToSubscribe;
    private String openid;
    public User getManager() {
        return manager;
    }
    public void setManager(User manager) {
        this.manager = manager;
    }
    public User getUserToSubscribe() {
        return userToSubscribe;
    }
    public void setUserToSubscribe(User userToSubscribe) {
        this.userToSubscribe = userToSubscribe;
    }
    public String getOpenid() {
        return openid;
    }
    public void setOpenid(String openid) {
        this.openid = openid;
    }
}

pom.xml中的jackson依赖项(我使用的是spring 3.1.0.RELEASE):

    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.9.10</version>
    </dependency>

rest-servlet.xml中的映射

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
   <property name="messageConverters">
       <list>
           <ref bean="jsonConverter" />
       </list>
   </property>
</bean>

<bean id="jsonConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
   <property name="supportedMediaTypes" value="application/json" />
</bean>

以及控制器方法的标题:

public @ResponseBody SimpleMessage subscribeUser(@RequestBody Subscription subscription)

作为POST的结果,我收到400不正确的请求错误.是可以这样做还是我需要使用@RequestBodyString或者@RequestBody Map<String,Object>自己解码JSON？

谢谢!

Answer 1

看着你的JSON

{
    "subscription": {
        "manager": {
            "username": "admin",
            "password": "admin"
        },
        "userToSubscribe": {
            "username": "newuser",
            "password": "newpassword",
            "email": "user@1and1.es"
        },
        "openid": "myopenid"
    }
}

根元素是subscription,它是一个JSON对象.你的Subscription班级没有subscription字段.所以没有什么可以映射subscription元素,因此它失败了400 Bad Request.

创建一个类 SubscriptionWrapper

public class SubscriptionWrapper {
    private Subscription subscription;

    public Subscription getSubscription() {
        return subscription;
    }

    public void setSubscription(Subscription subscription) {
        this.subscription = subscription;
    }
}

并更改您的处理程序方法以接受此类型的参数

public @ResponseBody SimpleMessage subscribeUser(@RequestBody SubscriptionWrapper subscriptionWrapper)

您可能需要配置ObjectMapperin MappingJacksonHttpMessageConverter(您应该使用的FYI MappingJackso2nHttpMessageConverter),以便它忽略缺少的属性.

Answer 2

我要回答我自己的问题。首先要特别感谢 Sotirios Delimanolis，因为他给了我钥匙，以便我调查正在发生的事情。

如您所知，我从视图中创建了以下 json：

{"manager":{"username":"admin","password":"admin"},"userToSubscribe":{"username":"newuser","password":"newpassword","email":"user@1and1.es"},"openid":"https://myopenid..."}

我稍微改变了它，因为我意识到没有必要创建一个对象订阅和一个 var 订阅。如果您像这样构建 JSON，它将完美运行：

var manager = {
    username: "admin",
    password: "admin"
};
var userToSubscribe = {
    username: "newuser",
    password: "newpassword",
    email: "user@1and1.es"
};

var openid = "https://myopenid...";

$.ajax({
    url: '/dp/rest/isUserSuscribed.json',
    type: 'POST',
    dataType: 'json',
    contentType: 'application/json',
    mimeType: 'application/json',
    data: JSON.stringify({manager : manager, userToSubscribe : userToSubscribe, openid : openid})   
});

控制器接收到这个 json：

@RequestMapping(method=RequestMethod.POST, value="/isUserSuscribed.json")
public @ResponseBody ResponseMessageElement<Boolean> isUserSuscribed(@RequestBody SubscriptionWrapper subscription){

和订阅包装...

private static class SubscriptionWrapper {
    BasicUser manager;
    BasicUser userToSubscribe;
    String openid;

    public BasicUser getManager() {
        return manager;
    }
    public void setManager(BasicUser manager) {
        this.manager = manager;
    }
    public BasicUser getUserToSubscribe() {
        return userToSubscribe;
    }
    public void setUserToSubscribe(BasicUser userToSubscribe) {
        this.userToSubscribe = userToSubscribe;
    }
    public String getOpenid() {
        return openid;
    }
    public void setOpenid(String openid) {
        this.openid = openid;
    }
}

那么……有什么问题吗？我收到了一个 Incorrect Request 400 错误……我按照 Sotirios 的建议调试了 MappingJackson2HttpMessageConverter，但出现了一个异常（没有合适的构造函数）。无论此类不是静态的，Jackson Mapping 都无法构建内部类。将 SubscriptionWrapper 设置为 static 是我问题的解决方案。

您还可以查看这些答案： http://stackoverflow.com/questions/8526333/jackson-error-no-suitable-constructor

http://stackoverflow.com/questions/12139380/how-to-convert-json-into-pojo-in-java-using-jackson

如果您有反序列化问题，请检查以下内容： http://stackoverflow.com/questions/17400850/is-jackson-really-unable-to-deserialize-json-into-a-generic-type

感谢所有的答复。