Jackson entity to JSON null or NULL to not participate in serialization

Http://www.cnblogs.com/yangy608/p/3936848.html

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1. On-Entity

@JsonInclude (Include.non_null)

Place the tag on the property, if the property is null, does not participate in serialization
If placed on top of a class, it works for all properties of the class
Include.Include.ALWAYS Default
The Include.non_default property is not serialized as the default value
Include.non_empty property is empty ("") or null is not serialized
Include.non_null property is NULL not serialized


2. On the Code
Objectmapper mapper = new Objectmapper ();

Mapper.setserializationinclusion (Include.non_null);

The Mapper object is set by this method, and all serialized objects are serialized according to the rules.
Include.Include.ALWAYS Default
The Include.non_default property is not serialized as the default value
Include.non_empty property is empty ("") or null is not serialized
Include.non_null property is NULL not serialized

User user = new User (1, "", null);
String Outjson = mapper.writevalueasstring (user);
System.out.println (Outjson);

Note: The Map list does not work for VO only

For example

 objectmapper mapper = new   Objectmapper (); Mapper.setserializationinclusion (Include.non_null); Map map  = new   HashMap (); Map.put ( "a" , null   "B", "B" ); String ret_val  = mapper.writevalueasstring (map); System.err.println (Ret_val); Map m  = Mapper.readvalue (ret_val, Map. Class   "a") + "|" + M.get ("B"  "B": "B", "a": null  }  null  |b 

New VO (); Vo.seta (null); Vo.setb (          "B"); == Mapper.readvalue (Ret_val1, VO.class+ "|" + V.GETB ());<br> output {"B": "B" }|b

Jackson entity to JSON null or NULL to not participate in serialization