Spring @ReponseBody @RequestBody 与抽象类 [英] Spring @ReponseBody @RequestBody with abstract class
问题描述
假设我有三个班级.
public abstract class Animal {}
public class Cat extends Animal {}
public class Dog extends Animal {}
我可以做这样的事情吗?
Can I do something like this?
输入:一个 JSON,它是 Dog 或 Cat
Input: a JSON which it is Dog or Cat
输出:狗/猫取决于输入对象类型
Output: a dog/cat depends on input object type
我不明白为什么下面的代码不起作用.或者我应该使用两种不同的方法来处理新的狗和猫?
I don't understand why the following code doesn't work. Or should I use two separate methods to handle new dog and cat?
@RequestMapping(value = "/animal", method = RequestMethod.POST, produces = "application/json; charset=utf-8")
private @ResponseBody <T extends Animal>T insertAnimal(@RequestBody T animal) {
return animal;
}
错误信息:
HTTP 状态 500 - 请求处理失败;嵌套异常是java.lang.IllegalArgumentException: 类型变量 'T' 不能是已解决
HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalArgumentException: Type variable 'T' can not be resolved
推荐答案
我自己刚刚找到了答案,这里是参考链接.
I just found the answer myself and here is the reference link.
我所做的是在抽象类之上添加了一些代码
What I have done is added some code above the abstract class
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonTypeInfo.*;
@JsonTypeInfo(use = Id.NAME, include = As.PROPERTY, property = "type")
@JsonSubTypes({
@JsonSubTypes.Type(value = Cat.class, name = "cat"),
@JsonSubTypes.Type(value = Dog.class, name = "dog")
})
public abstract class Animal{}
然后在html中的json输入中,
Then in the json input in HTML,
var inputjson = {
"type":"cat",
//blablabla
};
提交json后,最后在控制器中,
After submitting the json and finally in the controller,
@RequestMapping(value = "/animal", method = RequestMethod.POST, produces = "application/json; charset=utf-8", consumes=MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody insertanimal(@RequestBody Animal tmp) {
return tmp;
}
在这种情况下,变量 tmp 会自动转换为 Dog
或 Cat
对象,具体取决于 json 输入.
In this case variable tmp is automatically converted to a Dog
or Cat
object, depending on json input.
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