com.google.gson.annotations

注释类型 Until

@Documented
 @Retention(value=RUNTIME)
 @Target(value={FIELD,TYPE})
public @interface Until

An annotation that indicates the version number until a member or a type should be present. Basically, if Gson is created with a version number that exceeds the value stored in the Until annotation then the field will be ignored from the JSON output. This annotation is useful to manage versioning of your JSON classes for a web-service.

This annotation has no effect unless you build Gson with a GsonBuilder and invoke GsonBuilder.setVersion(double) method.

Here is an example of how this annotation is meant to be used:

 public class User {
   private String firstName;
   private String lastName;
   @Until(1.1) private String emailAddress;
   @Until(1.1) private String password;
 }
 

If you created Gson with new Gson(), the toJson() and fromJson() methods will use all the fields for serialization and deserialization. However, if you created Gson with Gson gson = new GsonBuilder().setVersion(1.2).create() then the toJson() and fromJson() methods of Gson will exclude the emailAddress and password fields from the example above, because the version number passed to the GsonBuilder, 1.2, exceeds the version number set on the Until annotation, 1.1, for those fields.

从以下版本开始:

1.3

必需元素概要

所需元素

限定符和类型	必需的元素和说明
double	value the value indicating a version number until this member or type should be ignored.

元素详细资料

value

public abstract double value

the value indicating a version number until this member or type should be ignored.