If the jackson object to json is NULL or empty, serialization is not performed.

If the jackson object to json is NULL or empty, serialization is not performed.

1. Entity

@ JsonInclude (Include. NON_NULL)

// Place the tag on the property. If the property is NULL, it is not involved in serialization.
// If it is placed on the top of the class, it takes effect for all the attributes of the class.
// Include. Include. ALWAYS default
// Include. NON_DEFAULT attribute is default value not serialized
// Include. NON_EMPTY property is NULL ("") or NULL is not serialized
// Include. NON_NULL attribute is NULL and is not serialized


2. Code
ObjectMapper mapper = new ObjectMapper ();

Mapper. setserializationsion Sion (Include. NON_NULL );

// Set the mapper object using this method. All serialized objects are serialized according to the modified rules.
// Include. Include. ALWAYS default
// Include. NON_DEFAULT attribute is default value not serialized
// Include. NON_EMPTY property is NULL ("") or NULL is not serialized
// Include. NON_NULL attribute is NULL and is not serialized

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

Jackson object to json attributes directly does not participate in serialization

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@ JsonIgnore

Private int id;