hibernate annotation

hibernate annotation主要是利用JPA的接口使元数据注释代替xml映射文件。如：
Java代码  
import java.io.Serializable;  
import java.util.Date;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.GenerationType;  
import javax.persistence.Id;  
import javax.persistence.Table;  
@Entity  
@Table(name="user")  
public class User implements Serializable{  
    private static final long serialVersionUID = 1L;  
    private int id;  
    private int age;  
    private String name;  
    private String password;  
    @Id  
    //采用数据库自增方式  
    @GeneratedValue(strategy=GenerationType.AUTO)  
    //@GeneratedValue  
    public int getId() {  
        return id;  
    }  
    public void setId(int id) {  
        this.id = id;  
    }  
    public int getAge() {  
        return age;  
    }  
    public void setAge(int age) {  
        this.age = age;  
    }  
    public static long getSerialversionuid() {  
        return serialVersionUID;  
    }  
    public String getName() {  
        return name;  
    }  
    public void setName(String name) {  
        this.name = name;  
    }  
    public String getPassword() {  
        return password;  
    }  
    public void setPassword(String password) {  
        this.password = password;  
    }  
}  
 hibernate.cfg.xml 配置
Java代码  
<hibernate-configuration>  
    <session-factory>  
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>  
        <property name="hibernate.connection.url">jdbc:mysql:///test</property>  
        <property name="hibernate.connection.username">root</property>  
        <property name="hibernate.connection.password">root</property>  
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>  
        <property name="hibernate.hbm2ddl.auto">update</property>  
        <property name="hibernate.show_sql">true</property>  
        <property name="hibernate.format_sql">true</property>  
        <mapping class="com.linkhome.annotation.User" />  
    </session-factory>  
</hibernate-configuration>  
 
hibernate.cfg.xml的读取：
Java代码  
Configuration cfg = new AnnotationConfiguration().configure();  
 
多对一关系，一对多：
Java代码  
import java.io.Serializable;  
import java.util.HashSet;  
import java.util.Set;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.Id;  
import javax.persistence.JoinColumn;  
import javax.persistence.OneToMany;  
import javax.persistence.Table;  
@Entity  
@Table(name = "class")  
public class Class implements Serializable {  
    private static final long serialVersionUID = 1L;  
    private int id;  
    private String name;  
    private Set<Student> st=new HashSet<Student>();  
  
    @Id  
    @GeneratedValue  
  
    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;  
    }  
  
    @OneToMany(mappedBy="classes",targetEntity=Student.class)  
    @JoinColumn(name="classID")  
  
  
  
    public Set<Student> getSt() {  
        return st;  
    }  
  
    public void setSt(Set<Student> st) {  
        this.st = st;  
    }  
  
    public static long getSerialversionuid() {  
        return serialVersionUID;  
    }  
      
      
  
}  
 
 
Java代码  
import java.io.Serializable;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.Id;  
import javax.persistence.JoinColumn;  
import javax.persistence.ManyToOne;  
import javax.persistence.Table;  
@Entity  
@Table(name = "student")  
  
public class Student implements Serializable {  
    private static final long serialVersionUID = 1L;  
    private int id;  
    private String name;  
    private String password;  
    private Class classes;  
    @Id  
    @GeneratedValue  
  
  
  
    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 getPassword() {  
        return password;  
    }  
  
    public void setPassword(String password) {  
        this.password = password;  
    }  
  
    public static long getSerialversionuid() {  
        return serialVersionUID;  
    }  
  
      
  
    @ManyToOne  
    @JoinColumn(name="classID")  
    public Class getClasses() {  
        return classes;  
    }  
  
    public void setClasses(Class classes) {  
        this.classes = classes;  
    }  
}