实体商品示例代码

package cn.maxhou.entity;

import java.io.Serializable;

import java.math.BigDecimal;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.ManyToOne;

@Entity//该注解表名该类为一个实体

public class Goods implements Serializable {

private static final long serialVersionUID = 5060150518287868308L;

@Id//id注解

@GeneratedValue(strategy=GenerationType.IDENTITY)//ID自增注解

private int id;

private String name;

private String specifications;

private BigDecimal price;

private int quantity;

@ManyToOne//表名商品和分类的关系是多对一

@JoinColumn(name = "classification_id")//设置加入类名

private Classification classification;

public Goods() {

}

public Goods(String name, String specifications, BigDecimal price, int quantity) {

super();

this.name = name;

this.specifications = specifications;

this.price = price;

this.quantity = quantity;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getSpecifications() {

return specifications;

}

public void setSpecifications(String specifications) {

this.specifications = specifications;

}

public BigDecimal getPrice() {

return price;

}

public void setPrice(BigDecimal price) {

this.price = price;

}

public int getQuantity() {

return quantity;

}

public void setQuantity(int quantity) {

this.quantity = quantity;

}

public Classification getClassification() {

return classification;

}

public void setClassification(Classification classification) {

this.classification = classification;

}

}

实体分类代码

package cn.maxhou.entity;

import java.io.Serializable;

import java.util.Set;

import javax.persistence.CascadeType;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.OneToMany;

@Entity//该注解表明该类是一个实体

public class Classification implements Serializable {

private static final long serialVersionUID = -7378975775604019219L;

@Id//I该注解表名改变量为数据库表ID

@GeneratedValue(strategy = GenerationType.IDENTITY)//id自增

private int id;

private String name;

private int pid;

@OneToMany(mappedBy = "classification" ,cascade = CascadeType.ALL )//表明分类和商品的关系是一对多,级联操作所有权限

private Set goodes;

public Classification() {

}

public Classification(String name, int pid) {

super();

this.name = name;

this.pid = pid;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getPid() {

return pid;

}

public void setPid(int pid) {

this.pid = pid;

}

}

数据库操作类数据

package cn.maxhou.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import cn.maxhou.entity.Goods;

public interface GoodsRepository extends JpaRepository {

}

实现JpaRepository接口后就能拥有增删改查的功能

驱动类

package cn.maxhou.demo;

import java.math.BigDecimal;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.CommandLineRunner;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.boot.autoconfigure.domain.EntityScan;

import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import cn.maxhou.dao.ClassificationRepository;

import cn.maxhou.dao.GoodsRepository;

import cn.maxhou.entity.Classification;

import cn.maxhou.entity.Goods;

@SpringBootApplication

@EnableJpaRepositories(basePackages = "cn.maxhou.dao")//导入数据库操作类包注解

@EntityScan(basePackages = "cn.maxhou.entity")//导入实体包注解

public class Application implements CommandLineRunner {

@Autowired

private ClassificationRepository classificationRepository;

@Autowired

private GoodsRepository goodsRepository;

public static void main(String[] args) {

SpringApplication.run(Application.class, args);

}

@Override

public void run(String... args) throws Exception {

//清除表中已有数据

classificationRepository.deleteAllInBatch();//实现接口后调用删除所有方法

goodsRepository.deleteAllInBatch();//实现接口后调用删除所有方法

//新建分类

Classification classify = new Classification("总分类",0);

classificationRepository.save(classify);

Classification subClassify = new Classification("服装",1);

classificationRepository.save(subClassify);

//新建商品

Goods goods = new Goods("围巾","红色，1米5",new BigDecimal(200),300);

goods.setClassification(subClassify);

//Goods goods2 = new Goods("鞋子","43码黑色",new BigDecimal(388),100);

//goods.setClassification(classificationRepository.getOne(2));

goodsRepository.save(goods);

//goodsRepository.save(goods2);

}

}