jackson 序列化成扁平化

@JsonUnwrapped注解,注解对应的字段对象上边.

序列化之后,json的层级就只有一层. 

做个必须  类似于复制文件夹,扁平化之后,就只复制文件,在目标地方不在创建子文件夹.

原json

{"name":"guofeipeng","password":"123","p":{"age":25,"sex":true,"birthday":"2014-12-22 07-15-29","word":"程序员","pname":"nomouse","salary":"2500.00"}}

扁平化json

{"name":"guofeipeng","password":"123","age":25,"sex":true,"birthday":"2014-12-22 07-16-38","word":"程序         员","pname":"nomouse","salary":"2500.00"}

其中的

prefix

suffix

还可以指定生成的key的前缀和后缀.

用处多为转实体类为出参.
官方注释:

 
   public class Parent {
     public int age;
     public Name name;
   }
   public class Name {
     public String first, last;
   }
 
  
  which would normally be serialized as follows (assuming @JsonUnwrapped
  had no effect):
 
   {
     "age" : 18,
     "name" : {
       "first" : "Joey",
       "last" : "Sixpack"
     }
   }
 
  can be changed to this:
 
   {
     "age" : 18,
     "first" : "Joey",
     "last" : "Sixpack"
   }
 
  by changing Parent class to:
 
   public class Parent {
     public int age;
     @JsonUnwrapped
     public Name name;
   }
 
  Annotation can only be added to properties, and not classes, as it is contextual.
 

  Also note that annotation only applies if
 

  
Value is serialized as JSON Object (can not unwrap JSON arrays using this
    mechanism)
    
  
Serialization is done using BeanSerializer, not a custom serializer
    
  
No type information is added; if type information needs to be added, structure can
    not be altered regardless of inclusion strategy; so annotation is basically ignored.