Jackson JSON 序列化，通过级别定义避免递归 [英] Jackson JSON serialization, recursion avoidance by level defining

问题描述

我使用 Jackson 库将我的 pojo 对象序列化为 JSON 表示.例如我有 A 类和 B 类:

I use Jackson library for serialization of my pojo objects into JSON representation. For example I have class A and class B:

class A {
  private int id;
  private B b;

  constructors...
  getters and setters
}

class B {
  private int ind;
  private A a;

  constructors...
  getters and setters
}

如果我想从 A 类序列化对象，那么在序列化时有一定的可能会得到递归.我知道我可以通过使用 @JsonIgnore 来阻止它.

If I want to serialize object from class A there is certain possibility to get recursion while it is serialized. I know i can stop it by using @JsonIgnore.

是否可以通过深度级别限制序列化?

比如如果级别是2，序列化会这样:

For example, if the level is 2, the serialization will go this way:

• 序列化a, level = 0 (0 <2 ok) - > 序列化
• 序列化a.b，级别=1(1 <2 ok) -> 序列化
• 序列化 a.b.a, level = 2 (2 < 2 not true) ->停止

提前致谢.

推荐答案

我最近遇到了类似的问题:Jackson - 具有双向关系的实体的序列化(避免循环)

I recently encountered a similar problem: Jackson - serialization of entities with birectional relationships (avoiding cycles)

所以解决方案是升级到Jackson 2.0，并在类中添加以下注释:

So the solution is to upgrade to Jackson 2.0, and add to classes the following annotation:

@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, 
                  property = "@id")
public class SomeEntityClass ...

这很完美.

这篇关于Jackson JSON 序列化，通过级别定义避免递归的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！