fastjson SerializerFeature 序列化策略

JSONObject.toJSONString(实体对象, SerializerFeature.WriteMapNullValue))

package com.alibaba.fastjson.serializer;

public enum SerializerFeature {
   QuoteFieldNames,
   UseSingleQuotes,
   WriteMapNullValue,
   WriteEnumUsingToString,
   WriteEnumUsingName,
   UseISO8601DateFormat,
   WriteNullListAsEmpty,
   WriteNullStringAsEmpty,
   WriteNullNumberAsZero,
   WriteNullBooleanAsFalse,
   SkipTransientField,
   SortField,
   /** @deprecated */
   @Deprecated
   WriteTabAsSpecial,
   PrettyFormat,
   WriteClassName,
   DisableCircularReferenceDetect,
   WriteSlashAsSpecial,
   BrowserCompatible,
   WriteDateUseDateFormat,
   NotWriteRootClassName,
   /** @deprecated */
   DisableCheckSpecialChar,
   BeanToArray,
   WriteNonStringKeyAsString,
   NotWriteDefaultValue,
   BrowserSecure,
   IgnoreNonFieldGetter;

   public final int mask = 1 << this.ordinal();
   public static final SerializerFeature[] EMPTY = new SerializerFeature[0];
   public static final int WRITE_MAP_NULL_FEATURES = WriteMapNullValue.getMask() | WriteNullBooleanAsFalse.getMask() | WriteNullListAsEmpty.getMask() | WriteNullNumberAsZero.getMask() | WriteNullStringAsEmpty.getMask();

   private SerializerFeature() {
   }

   public final int getMask() {
       return this.mask;
   }

   public static boolean isEnabled(int features, SerializerFeature feature) {
       return (features & feature.mask) != 0;
   }

   public static boolean isEnabled(int features, int fieaturesB, SerializerFeature feature) {
       int mask = feature.mask;
       return (features & mask) != 0 || (fieaturesB & mask) != 0;
   }

   public static int config(int features, SerializerFeature feature, boolean state) {
       if (state) {
           features |= feature.mask;
       } else {
           features &= ~feature.mask;
       }

       return features;
   }

   public static int of(SerializerFeature[] features) {
       if (features == null) {
           return 0;
       } else {
           int value = 0;
           SerializerFeature[] var2 = features;
           int var3 = features.length;

           for(int var4 = 0; var4 < var3; ++var4) {
               SerializerFeature feature = var2[var4];
               value |= feature.mask;
           }

           return value;
       }
   }
}

int features=SerializerFeature.config(JSON.DEFAULT_GENERATE_FEATURE, SerializerFeature.WriteEnumUsingName, false)
JSON.toJSONString(obj,features,SerializerFeature.EMPTY);

[
    {
        "$ref": "$.itemSkuList[0].itemSpecificationList[0]"
    },
    {
        "$ref": "$.itemSkuList[1].itemSpecificationList[0]"
    }
]

A a = new A();  
B b = new B(a);  
a.setB(b);  
String text = JSON.toJSONString(a); //{"b":{"a":{"$ref":".."}}}  
A a1 = JSON.parseObject(text, A.class);  
Assert.assertTrue(a1 == a1.getB().getA()); 

"$ref":".."  上一级
"$ref":"@"   当前对象，也就是自引用
"$ref":"$"   根对象
"$ref":"$.children.0"   基于路径的引用，相当于 root.getChildren().get(0)

JSON.DEFFAULT_DATE_FORMAT = “yyyy-MM-dd”;
JSON.toJSONString(obj, SerializerFeature.WriteDateUseDateFormat);