Hibernate中的注解说明

 1 @Entity
 2 public class Hansband {
 3     private int id;
 4     private String username;
 5     private Wife wife;
 6    
 7     @Id
 8     @GeneratedValue(strategy = GenerationType.IDENTITY)
 9     public int getId() {
10         return id;
11     }
12    
13     @Column
14     public String getUsername() {
15         return username;
16     }
17     /**
18       * @OneToOne：一对一关联
19       * cascade：级联,它可以有有五个值可选,分别是：
20       * CascadeType.PERSIST：级联新建
21       * CascadeType.REMOVE : 级联删除
22       * CascadeType.REFRESH：级联刷新
23       * CascadeType.MERGE  ： 级联更新
24       * CascadeType.ALL    ： 以上全部四项
25       * @JoinColumn:主表外键字段
26       * wifeId：Hansband所映射的表中的一个字段
27       */
28     @OneToOne
29     @JoinColumn(name="wifeId")
30     public Wife getWife() {
31         return wife;
32     }
33     public void setId(int id) {
34         this.id = id;
35     }
36     public void setUsername(String username) {
37         this.username = username;
38     }
39     public void setWife(Wife wife) {
40         this.wife = wife;
41     }
42 }
43 
44 
45 @Entity
46 public class Wife {
47     private int id ;
48     private String username;
49     private Hansband hansband;
50    
51     @Id
52     @GeneratedValue(strategy = GenerationType.AUTO)
53     public int getId() {
54         return id;
55     }
56     public String getUsername() {
57         return username;
58     }
59     public void setId(int id) {
60         this.id = id;
61     }
62     public void setUsername(String username) {
63         this.username = username;
64     }
65    /**
66      * @OneToOne：一对一关联
67      * mappedBy = "wife"：意思是说这里的一对一配置参考了wife
68      * wife又是什么呢?wife是Husband类中的getWife(),注意不是Husband类中的
69      * wife属性,Husband类中的OneToOne配置就是在getWife()方法上面配的.
70      * 如果Husband类中的getWife()方法改成getNewHusband(),其他不变的话,
71      * 这里就要写成：mappedBy = "new Husband"
72      */
73     @OneToOne(mappedBy="wife")
74     public Hansband getHansband() {
75         return hansband;
76     }
77     public void setHansband(Hansband hansband) {
78         this.hansband = hansband;
79     }
80 }

@Entity
@Table(name = "t_employee")
public class Employee {

    private Integer employeeId;
    private String  employeeName;
    private Company company;
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Integer getEmployeeId() {
        return employeeId;
    }
     /**
      * @ManyToOne：多对一关联
      * cascade：级联,它可以有有五个值可选,分别是：
      * CascadeType.PERSIST：级联新建
      * CascadeType.REMOVE : 级联删除
      * CascadeType.REFRESH：级联刷新
      * CascadeType.MERGE  ： 级联更新
      * CascadeType.ALL    ： 以上全部四项
      * fetch = FetchType.LAZY,延迟加载策略,如果不想延迟加载可以用FetchType.EAGER
      * @JoinColumn:主表外键字段
      * cid：Employee所映射的表中的一个字段
      */
    @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH},fetch = FetchType.LAZY)
    @JoinColumn(name = "cid")
    public Company getCompany() {
        return company;
    }
    public String getEmployeeName() {
        return employeeName;
    }
    public void setEmployeeId(Integer employeeId) {
        this.employeeId = employeeId;
    }
    public void setEmployeeName(String employeeName) {
        this.employeeName = employeeName;
    }
    public void setCompany(Company company) {
        this.company = company;
    }
}


@Entity
@Table(name = "t_company")
public class Company {

    private Integer companyId;
    private String  companyName;
    private Set<Employee> employees;
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Integer getCompanyId() {
        return companyId;
    }
    /**
     * @OneToMany：一对多关联
     * mappedBy = "company"：意思是说这里的一对一配置参考了company
     * company又是什么呢?company是Employ类中的getCompany(),注意不是Employ类中的
     * company属性,Employ类中的OneToMany配置就是在getCompany()方法上面配的.
     * 如果Employ类中的getCompany()方法改成getNewCompany(),其他不变的话,
     * 这里就要写成：mappedBy = "newCompany"
     */
    @OneToMany(mappedBy = "company")
    public Set<Employee> getEmployees() {
        return employees;
    }
    public String getCompanyName() {
        return companyName;
    }
    public void setCompanyId(Integer companyId) {
        this.companyId = companyId;
    }
    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }
    public void setEmployees(Set<Employee> employees) {
        this.employees = employees;
    }
}

@Entity
@Table(name="rong_user")
public class User{

    //省略其它内容

    private Set<Role> roles = new LinkedHashSet<Role>();//角色集合
    
    @ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
    //name是数据库中间表名
    @JoinTable(name = "rong_user_role", joinColumns = { @JoinColumn(name ="user_id" )}, inverseJoinColumns = { @JoinColumn(name = "role_id") })
    @OrderBy("id")
    public Set<Role> getRoles() {
        return roles;
    }
    public void setRoles(Set<Role> roles) {
        this.roles = roles;
    }
}


@Entity
@Table(name="rong_role")
public class Role{
    
    //省略其它内容

    private Set<User> user = new LinkedHashSet<User>();//用户集合

    @ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, mappedBy = "roles", fetch = FetchType.LAZY)
    public Set<User> getUser() {
        return user;
    }
    public void setUser(Set<User> user) {
        this.user = user;
    }
}