相关概念:http://www.cnblogs.com/mandroid/archive/2011/07/18/2109829.html

定义注解

package cn.baokx.annotation;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Target(value={ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyTableAnnotation {String value();
}

package cn.baokx.annotation;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Target(value={ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyFieldAnnotation {String columnName();String type();
}

package cn.baokx.annotation;
@MyTableAnnotation("TBL_STUDENT")
public class Student {@MyFieldAnnotation(columnName="NAME",type="VARCHAR")private String name;@MyFieldAnnotation(columnName="AGE",type="INT")private int age;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}}

package cn.baokx.annotation;import java.lang.reflect.Field;public class Main {public static void main(String[] args) throws NoSuchFieldException, SecurityException, ClassNotFoundException {Student stu = new Student();stu.setName("baokx");stu.setAge(30);handler(stu);}public static void handler(Student stu) throws NoSuchFieldException, SecurityException, ClassNotFoundException{Class clazz = stu.getClass();MyTableAnnotation mta = (MyTableAnnotation) clazz.getAnnotation(MyTableAnnotation.class);System.out.println("tableName:"+mta.value());Field f = clazz.getDeclaredField("name");MyFieldAnnotation mfa = f.getAnnotation(MyFieldAnnotation.class);System.out.println("columnName:"+mfa.columnName());System.out.println("type:"+mfa.type());System.out.println("value:"+stu.getName());f = clazz.getDeclaredField("age");mfa = f.getAnnotation(MyFieldAnnotation.class);System.out.println("columnName:"+mfa.columnName());System.out.println("type:"+mfa.type());System.out.println("value:"+stu.getAge());}
}