JSON.toJSONString(obj, SerializerFeature.PrettyFormat)导致循环引用path异常

[txgj]

    IssueCR root = new IssueCR();
    IssueCA a = new IssueCA();
    IssueCB b= new IssueCB();
    IssueCC c = new IssueCC();
    IssueCD d = new IssueCD();

    root.setA(a);
    a.setB(Lists.newArrayList(b).toArray());
    b.setC(c);
    c.setD(d);
    d.setE(Lists.newArrayList(c));


    System.out.println(JSON.toJSONString(root, SerializerFeature.PrettyFormat, SerializerFeature.WriteMapNullValue));
    System.out.println(JSON.toJSONString(root));

第一个输出： { "a":{ "b":[ { "c":{ "d":{ "e":[ {"$ref":"$.a.b.null.c"} ] } } } ] } }

第二个输出： {"a":{"b":[{"c":{"d":{"e":[{"$ref":"$.a.b[0].c"}]}}}]}}

因为使用SerializerFeature.PrettyFormat时，在处理数组的序列化时，走了不同的逻辑，导致出现{"$ref":"$.a.b.null.c"}

[Certseeds]

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.google.common.collect.Lists;
import lombok.Data;
import org.junit.Test;

import java.util.ArrayList;

public class Issue3672 {
    @Test
    public void test1() {
        Issue3672Root root = new Issue3672Root();
        Issue3672A a = new Issue3672A();
        Issue3672B b = new Issue3672B();
        Issue3672C c = new Issue3672C();
        Issue3672D d = new Issue3672D();
        root.setA(a);
        a.setB(Lists.newArrayList(b).toArray());
        b.setC(c);
        c.setD(d);
        d.setE(Lists.newArrayList(c));
        System.out.println(JSON.toJSONString(root, SerializerFeature.PrettyFormat, SerializerFeature.WriteMapNullValue));
        System.out.println(JSON.toJSONString(root));
    }

    @Data
    private class Issue3672Root {
        private Issue3672A a;
    }

    @Data
    private class Issue3672A {
        private Object[] b;
    }

    @Data
    private class Issue3672B {
        private Issue3672C c;
    }

    @Data
    private class Issue3672C {
        private Issue3672D d;
    }

    @Data
    private class Issue3672D {
        private ArrayList<Issue3672C> e;
    }

}

运行输出如下

{
	"a":{
		"b":[
			{
				"c":{
					"d":{
						"e":[
							{"$ref":"$.a.b.null.c"}
						]
					}
				}
			}
		]
	}
}
{"a":{"b":[{"c":{"d":{"e":[{"$ref":"$.a.b[0].c"}]}}}]}}

复现如上

[Certseeds]

PS:

a.setB(Lists.newArrayList(b).toArray());
...
private Object[] b;

to

a.setB(Lists.newArrayList(b).toArray(new Issue3672B[0]));
...
private Issue3672B[] b;

输出就不会有null了