@AttributeOverride with Inheritance

msi_333 · **Posted:** Mon Apr 26, 2010 11:48 am

Following example show properties overloading.To do this you need to use @AttributeOverride annotation .Take in mind , that am using "TABLE_PER_CLASS" inheritance type here . @AttributeOverride can be used with other ways , you can find it also in JPA examples section.

Below you can find the entities:

Code:

package com.codemiles.jpa;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.Table;
 
@Entity
@Table(name="SHAPE")
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
public class Shape implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    @Id
    protected int id;
    protected int scale;
    protected float rotate;
    protected String colour;
    protected String points;
    protected int numOfPoints;
    
    public Shape(){
    id=(int)System.currentTimeMillis();
    }
    @Column(name="SHAPE_ID")
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }
    @Column(name="SCALE")
    public int getScale() {
        return scale;
    }

    public void setScale(int scale) {
        this.scale = scale;
    }
    @Column(name="ROTATE")
    public float getRotate() {
        return rotate;
    }

    public void setRotate(float rotate) {
        this.rotate = rotate;
    }
 
    @Column(name="POINTS")
    public String getPoints() {
        return points;
    }

    public void setPoints(String points) {
        this.points = points;
    }

    public void setColour(String colour) {
    this.colour = colour;
    }
    @Column(name="COLOUR")
    public String getColour() {
    return colour;
    }
    public void setNumOfPoints(int numOfPoints) {
    this.numOfPoints = numOfPoints;
    }
    @Column(name="NUM_POINTS")
    public int getNumOfPoints() {
    return numOfPoints;
    }
    
}

 

Circle shape :

Code:

package com.codemiles.jpa;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.AttributeOverride;
import javax.persistence.Entity;
import javax.persistence.Table;

@Entity
@Table(name="CIRCLE")
@AttributeOverride(name="rotate", column=@Column(name="ROTATE_Circle"))
public class Circle extends Shape implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    protected float radius; 
  

    
    public Circle(){
    super();
    numOfPoints =1 ;
    
    }


    public void setRadius(float radius) {
    this.radius = radius;
    }

    @Column(name="RADIUS")
    public float getRadius() {
    return radius;
    }
}

 

@AttributeOverride with Inheritance

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