Hibernate Annotation (…

引自：http://www.cnblogs.com/hongten/archive/2011/07/20/2111773.html

进入：http://www.hibernate.org

说明文档：

英文：http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html_single/

中文：http://docs.jboss.org/hibernate/annotations/3.4/reference/zh_cn/html_single/

下载：hibernate annotation 3.4.0 GA

得到：hibernate-annotations.jar

　　　hibernate-commons-annotation.jar

　　　ejb3-persistence.jar

数据库：mysql

category表：id，name，description       id

product表：id,name ,price, description ,category_id                  id  category_id

新建java project项目：

Add Hibernate Capabilities

hibernate.cfg.xml


 1
 2
 3           "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 4           "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
 5 
 6
 7
 8 
 9  
10  
11    org.hibernate.dialect.MySQLDialect
12  
13  
14    jdbc:mysql://localhost:3307/users
15  
16   root
17   root
18  
19    com.mysql.jdbc.Driver
20  
21  
22    mysqlusers
23  
24   true
25   true
26   thread
27  
28  
29 
30  
31 
32

利用Hibernate的逆向工程生成：

Category.java      and           Product.java   

Category.java


 1 package com.b510.examples;
 2 
 3 import java.util.HashSet;
 4 import java.util.Set;
 5 
 6 // 标准注解
 7 
 8 import javax.persistence.CascadeType;
 9 import javax.persistence.Column;
10 import javax.persistence.Entity;
11 import javax.persistence.FetchType;
12 import javax.persistence.GeneratedValue;
13 import javax.persistence.Id;
14 import javax.persistence.OneToMany;
15 import javax.persistence.Table;
16 
17 //增加的注解
18 
19 import org.hibernate.annotations.GenericGenerator;
20 
21 //当前的类是一个持久化类，是Category这个类。他映射了一个表category。所对应的 数据库是users
22 //这句：@Table(name = "category", catalog = "users")  可以省略
23 @Entity
24 @Table(name = "category", catalog = "users")
25 
26 public class Category implements java.io.Serializable {
27 
28  private static final long serialVersionUID = 3240281547213597385L;
29  private Integer id;
30  private String name;
31  private String description;
32  private Set products = new HashSet(0);
33 
34  
35  public Category() {
36  }
37 
38  public Category(String name, String description, Set products) {
39   this.name = name;
40   this.description = description;
41   this.products = products;
42  }
43 
44  // 主键 ：@Id    主键生成方式：strategy = "increment"
45  //映射表中id这个字段，不能为空，并且是唯一的
46  @GenericGenerator(name = "generator", strategy = "increment")
47  @Id
48  @GeneratedValue(generator = "generator")
49  @Column(name = "id", unique = true, nullable = false)
50  public Integer getId() {
51   return this.id;
52  }
53 
54  public void setId(Integer id) {
55   this.id = id;
56  }
57 
58  //映射表中name这个字段 ，长度是500
59  @Column(name = "name", length = 500)
60  public String getName() {
61   return this.name;
62  }
63 
64  public void setName(String name) {
65   this.name = name;
66  }
67  
68  //映射表中description这个字段 ，长度是500
69  @Column(name = "description", length = 500)
70  public String getDescription() {
71   return this.description;
72  }
73 
74  public void setDescription(String description) {
75   this.description = description;
76  }
77 
78  //级联操作：cascade = CascadeType.ALL
79  //延迟加载：fetch = FetchType.LAZY
80  //映射：mappedBy = "category"
81  //一对多方式
82  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "category")
83  public Set getProducts() {
84   return this.products;
85  }
86 
87  public void setProducts(Set products) {
88   this.products = products;
89  }
90 
91 }

Product.java


 1 package com.b510.examples;
 2 
 3 import javax.persistence.Column;
 4 import javax.persistence.Entity;
 5 import javax.persistence.FetchType;
 6 import javax.persistence.GeneratedValue;
 7 import javax.persistence.Id;
 8 import javax.persistence.JoinColumn;
 9 import javax.persistence.ManyToOne;
10 import javax.persistence.Table;
11 import org.hibernate.annotations.GenericGenerator;
12 
13 
14 @Entity
15 @Table(name = "product", catalog = "users")
16 public class Product implements java.io.Serializable {
17 
18  private static final long serialVersionUID = -1546206493725028472L;
19  private Integer id;
20  private Category category;
21  private String name;
22  private String price;
23  private String descripton;
24 
25  
26  public Product() {
27  }
28 
29  public Product(Category category, String name, String price,
30    String descripton) {
31   this.category = category;
32   this.name = name;
33   this.price = price;
34   this.descripton = descripton;
35  }
36  
37  @GenericGenerator(name = "generator", strategy = "increment")
38  @Id
39  @GeneratedValue(generator = "generator")
40  @Column(name = "id", unique = true, nullable = false)
41  public Integer getId() {
42   return this.id;
43  }
44 
45  public void setId(Integer id) {
46   this.id = id;
47  }
48 
49  //延迟加载：多对一方式
50  //关联信息：外键name = "category_id"
51  @ManyToOne(fetch = FetchType.LAZY)
52  @JoinColumn(name = "category_id")
53  public Category getCategory() {
54   return this.category;
55  }
56 
57  public void setCategory(Category category) {
58   this.category = category;
59  }
60 
61  @Column(name = "name", length = 500)
62  public String getName() {
63   return this.name;
64  }
65 
66  public void setName(String name) {
67   this.name = name;
68  }
69 
70  @Column(name = "price", length = 10)
71  public String getPrice() {
72   return this.price;
73  }
74 
75  public void setPrice(String price) {
76   this.price = price;
77  }
78 
79  @Column(name = "descripton", length = 500)
80  public String getDescripton() {
81   return this.descripton;
82  }
83 
84  public void setDescripton(String descripton) {
85   this.descripton = descripton;
86  }
87 
88 }

测试代码：

HibernateTest.java


 1
 4 package com.b510.examples;
 5 
 6 import java.util.Set;
 7 
 8 import org.hibernate.Session;
 9 import org.hibernate.SessionFactory;
10 import org.hibernate.cfg.AnnotationConfiguration;
11 import org.hibernate.cfg.Configuration;
12 
13
20 public class HibernateTest {
21 
22  public static void main(String[] args) {
23   HibernateTest test=new HibernateTest();
24   test.add();
25   test.find();
26  }
27  public void add(){
28  Configuration config=new AnnotationConfiguration();
29  config.configure();
30  SessionFactory sessionFactory=config.buildSessionFactory();
31  Session session=sessionFactory.getCurrentSession();
32  session.beginTransaction();
33  Category c=(Category)session.get(Category.class, 5);
34  
35  Product p=new Product();
36  p.setName("计算机科学与技术");
37  p.setPrice("123");
38  p.setDescripton("计算机科学与技术,好啊，真是红啊");
39  
40  p.setCategory(c);
41  c.getProducts().add(p);
42  
43  session.save(p);
44  session.getTransaction().commit();
45  }
46  
47  
48  public void find(){
49   Configuration config=new AnnotationConfiguration();
50   config.configure();
51   SessionFactory sessionFactory=config.buildSessionFactory();
52   Session session=sessionFactory.getCurrentSession();
53   session.beginTransaction();
54   Category c=(Category)session.get(Category.class, 5);
55    System.out.println("id: "+c.getId()+"  name:"+c.getName());
56    Set p=c.getProducts();
57    for(Product product:p){
58     System.out.println("id:"+product.getId()+"  name:"+product.getName()+"  description:"+product.getDescripton());
59    }
60    session.getTransaction().commit();
61  }
62 }

运行效果：


 1 log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
 2 log4j:WARN Please initialize the log4j system properly.
 3 Hibernate: 
 4     select
 5         category0_.id as id1_0_,
 6         category0_.description as descript2_1_0_,
 7         category0_.name as name1_0_ 
 8     from
 9         users.category category0_ 
10     where
11         category0_.id=?
12 Hibernate: 
13     select
14         products0_.category_id as category5_1_,
15         products0_.id as id1_,
16         products0_.id as id0_0_,
17         products0_.category_id as category5_0_0_,
18         products0_.descripton as descripton0_0_,
19         products0_.name as name0_0_,
20         products0_.price as price0_0_ 
21     from
22         users.product products0_ 
23     where
24         products0_.category_id=?
25 Hibernate: 
26     select
27         max(id) 
28     from
29         product
30 Hibernate: 
31     insert 
32     into
33         users.product
34         (category_id, descripton, name, price, id) 
35     values
36         (?, ?, ?, ?, ?)
37 Hibernate: 
38     select
39         category0_.id as id5_0_,
40         category0_.description as descript2_5_0_,
41         category0_.name as name5_0_ 
42     from
43         users.category category0_ 
44     where
45         category0_.id=?
46 id: 5  name:xml33
47 Hibernate: 
48     select
49         products0_.category_id as category5_1_,
50         products0_.id as id1_,
51         products0_.id as id4_0_,
52         products0_.category_id as category5_4_0_,
53         products0_.descripton as descripton4_0_,
54         products0_.name as name4_0_,
55         products0_.price as price4_0_ 
56     from
57         users.product products0_ 
58     where
59         products0_.category_id=?
60 id:9  name:计算机科学与技术  description:计算机科学与技术,好啊，真是红啊

 

分类: Hibernate
标签: java, hibernate, annotation, 注解
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posted @ 2014-03-24 13:07  JamesFan  阅读(174)  评论(0)  编辑  收藏  举报