解决 fastjson 对象转 json string 循环引用栈溢出的问题

对象是 1 对多，多对 1 的双向映射关系。

public class Student {

    private Long id;

    private String name;

    private Classroom classroom;
}

public class Classroom {

    private Long id;

    private List<Student> students;
}

报错信息如下：

Exception in thread "main" java.lang.StackOverflowError
    at com.alibaba.fastjson.JSON.getMixInAnnotations(JSON.java:1383)
    at com.alibaba.fastjson.serializer.SerializeConfig.get(SerializeConfig.java:890)
    at com.alibaba.fastjson.serializer.SerializeConfig.getObjectWriter(SerializeConfig.java:446)
    at com.alibaba.fastjson.serializer.SerializeConfig.getObjectWriter(SerializeConfig.java:442)
    at com.alibaba.fastjson.serializer.JSONSerializer.getObjectWriter(JSONSerializer.java:448)
    at com.alibaba.fastjson.serializer.JSONSerializer.writeWithFieldName(JSONSerializer.java:358)
    at com.alibaba.fastjson.serializer.ASMSerializer_2_Classroom.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_1_Student.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_2_Classroom.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_1_Student.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_2_Classroom.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_1_Student.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_2_Classroom.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_1_Student.writeDirectNonContext(Unknown Source)
    at com.alibaba.fastjson.serializer.ASMSerializer_2_Classroom.writeDirectNonContext(Unknown Source)

解决方法：

1.在双向映射的一方添加 “@JSONField(serialize = false)”。

public class Classroom {

    private Long id;

    @JSONField(serialize = false)
    private List<Student> students;
}

2.不要开启 SerializerFeature.DisableCircularReferenceDetect。

原文链接：https://miansen.wang/2020/10/26/fastjson-stackoverflow-error/