orderitem.java

来自「jboss4 + Mysql +ejb3.0 EJB3 简单例子」· Java 代码 · 共 72 行

/**
 * Copyright (c)上海烟草(集团)公司与上海康时信息系统有限公司。
 */
package com.myejb.entity;

import java.io.Serializable;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;


/**
 * 
 * @author xywang
 * @since 2009-2-13
 * @version 1.0
 */
@SuppressWarnings("serial")
@Entity
@Table(name="OrderItems")
public class OrderItem implements Serializable{
    private Integer id;
    private String productname;
    private Float price;
    private Orders order;
    public OrderItem(){}
    public OrderItem(String productname,Float price){
        this.productname = productname;
        this.price       = price;
    }
    @Id
    @GeneratedValue
    public Integer getId(){
        return id;
    }
    public void setId(Integer id){
        this.id = id;
    }
    /**
     * 多对一:@ManyToOne注释的fetch属性默认值是FetchType.EAGER。
     * 关联关系维护：optional:false时当OrderItem不存在时，查询Orders时为null,true时当OrderItem不存在时仍可以查询Orders但其中的OrderItem为Null
     *              也就是false时为inner join,optional=true时为left join。
     * 关联键：@JoinColumn(name="order_id")注释指定OrderItem映射表的order_id列作为外键与Orders映射表的主键列关联。             
     */
    @ManyToOne(cascade=CascadeType.ALL,optional=false)
    @JoinColumn(name="order_id")
    public Orders getOrder(){
        return order;
    }
    public void setOrder(Orders order){
        this.order = order;
    }
    public Float getPrice(){
        return price;
    }
    public void setPrice(Float price){
        this.price = price;
    }
    public String getProductname(){
        return productname;
    }
    public void setProductname(String productname){
        this.productname = productname;
    }
    
}