java-使用反射实现ORM映射

自定义两个注解

package com.moon.ROM;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface SexFileAnnotation {
    String name();
    String type();
    int length();

}

package com.moon.ROM;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface SexTable {
    String value();

}

package com.moon.ROM;
@SexTable("tb_student")
public class SxtStudent {
    @SexFileAnnotation(name ="studentName" ,type = "vachar",length = 10)
    private String studentName;
    @SexFileAnnotation(name="age",type = "int",length = 3)
    private int age;
    @SexFileAnnotation(name = "id",type = "int",length = 5)
    private int id;

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }
}

package com.moon.ROM;

import java.lang.reflect.Field;

public class Test {
    public static void main(String[] args) {
        try {
            Class clazz = Class.forName("com.moon.ROM.SxtStudent");
//            Annotation[] annotations = clazz.getAnnotations();
           /* for (Annotation annotation : annotations) {
                System.out.println(annotation);

            }*/
           SexTable st = (SexTable) clazz.getAnnotation(SexTable.class);
            Field f = clazz.getDeclaredField("studentName");
            SexFileAnnotation sexf = f.getAnnotation(SexFileAnnotation.class);
            System.out.println(sexf.name()+"---"+sexf.type()+"---"+sexf.length());


        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}