gson

FastJson

循环引用的问题

Circular reference problem

If the same object is added to a List multiple times, it will be converted to this by default in JSON.toJSONString:

[
    {
        "k1": "v1",
        "k2": []
    },
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"},
    {"$ref": "$.paras[0]"}
]

I have added it to the List many times because of the misoperation, so it is good to solve the misoperation.

As for the case where it is really the real intention (maybe only the front end?), you can refer to http://blog.csdn.net/Singleton1900/article/details/50435247 to solve it.

boolean serialization field naming

public class Test {
    private boolean isTest;

    public boolean isTest() {
        return isTest;
    }

    public void setTest(boolean isTest) {
        this.isTest = isTest;
    }
}

When objects of this class use the JSON.toJSONString method, the isTest field name is changed to test.

There are several ways to solve it:

1. Change the field name to test (compliant with Java Bean)

2. Annotate the field name, indicating that its serialized name is isTest

3. Using Gson

The related discussion issues in the FastJson project are as follows:

https://github.com/alibaba/fastjson/issues/278