Java @JsonIgnore 和 @JsonBackReference、@JsonManagedReference 之间的区别
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/37392733/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Difference between @JsonIgnore and @JsonBackReference, @JsonManagedReference
提问by Kalyan Pradhan
I know both @JsonIgnoreand @JsonManagedReference, @JsonBackReferenceare used to solve the Infinite recursion (StackOverflowError), what is the difference between these two?
@JsonIgnore和@JsonManagedReference，我都知道，@JsonBackReference都是用来解决的Infinite recursion (StackOverflowError)，这两个有什么区别？
Note :These are Hymanson annotations.
注意：这些是 Hymanson 注释。
采纳答案by varren
Lets suppose we have
让我们假设我们有
private class Player {
public int id;
public Info info;
}
private class Info {
public int id;
public Player parentPlayer;
}
// something like this:
Player player = new Player(1);
player.info = new Info(1, player);
Serialization
序列化
@JsonIgnore
@JsonIgnore
private class Info {
public int id;
@JsonIgnore
public Player parentPlayer;
}
and @JsonManagedReference+ @JsonBackReference
和@JsonManagedReference+@JsonBackReference
private class Player {
public int id;
@JsonManagedReference
public Info info;
}
private class Info {
public int id;
@JsonBackReference
public Player parentPlayer;
}
will produce same output. And outputfor demo case from above is: {"id":1,"info":{"id":1}}
将产生相同的输出。并输出从上面演示的情况是：{"id":1,"info":{"id":1}}
Deserialization
反序列化
Here is main difference, because deserialization with @JsonIgnorewill just set null to the field so in our example parentPlayer will be == null.
这是主要区别，因为反序列化@JsonIgnore只会将字段设置为 null，因此在我们的示例中 parentPlayer 将为 == null。
But with @JsonManagedReference+ @JsonBackReferencewe will get Inforeferance there
但是使用@JsonManagedReference+@JsonBackReference我们将在Info那里获得参考
回答by Ali Dehghani
are used to solve the Infinite recursion (StackOverflowError)
用于解决无限递归（StackOverflowError）
@JsonIgnoreis not designed to solve the Infinite Recursionproblem, it just ignores the annotated property from being serialized or deserialized. But if there was a two-way linkage between fields, since @JsonIgnoreignores the annotated property, you may avoid the infinite recursion.
@JsonIgnore不是为了解决无限递归问题而设计的，它只是忽略了被序列化或反序列化的注释属性。但是如果字段之间存在双向链接，由于@JsonIgnore忽略了注释属性，您可以避免无限递归。
On the other hand, @JsonManagedReferenceand @JsonBackReferenceare designed to handle this two-way linkage between fields, one for Parentrole, the other for Childrole, respectively:
另一方面，@JsonManagedReferenceand@JsonBackReference旨在处理字段之间的这种双向链接，一个用于父角色，另一个用于子角色：
For avoiding the problem, linkage is handled such that the property annotated with
@JsonManagedReferenceannotation is handled normally (serialized normally, no special handling for deserialization) and the property annotated with@JsonBackReferenceannotation is not serialized; and during deserialization, its value is set to instance that has the "managed" (forward) link.
为避免该问题，对链接进行处理，使得注解的属性
@JsonManagedReference正常处理（正常序列化，反序列化不做特殊处理），@JsonBackReference不序列化注解的属性；并且在反序列化期间，它的值被设置为具有“托管”（前向）链接的实例。
To recap, if you don't need those properties in the serialization or deserialization process, you can use @JsonIgnore. Otherwise, using the @JsonManagedReference/@JsonBackReferencepair is the way to go.
回顾一下，如果您在序列化或反序列化过程中不需要这些属性，则可以使用@JsonIgnore. 否则，使用@JsonManagedReference/@JsonBackReference对是可行的方法。
