constraints.java

来自「《Java编程思想》第四版源代码」· Java 代码 · 共 12 行

//: annotations/database/Constraints.java
package annotations.database;
import java.lang.annotation.*;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Constraints {
  boolean primaryKey() default false;
  boolean allowNull() default true;
  boolean unique() default false;
} ///:~