这篇文章将为大家详细讲解有关在Spring框架中如何集成JPA实例，小编觉得挺实用的，因此分享给大家做个参考，希望大家阅读完这篇文章后可以有所收获。
Hibernate 3.2支持JPA注解，Spring集成JPA是可选的。
实体类MyUser，使用JPA注解实现到数据库表myUser的映射，如下所示：
package org.shirdrn.entity; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Transient; @Entity
public class MyUser {private Long id; private String userName; private String password; private String gender; private Integer age; private Integer birthYear; private String addr; private String email; @Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Long getId() {
return id;
}public void setId(Long id) {
this.id = id;
}@Column(name="userName")
public String getUserName() {
return userName;
}public void setUserName(String userName) {
this.userName = userName;
}@Column(name="password")
public String getPassword() {
return password;
}public void setPassword(String password) {
this.password = password;
}@Column(name="gender")
public String getGender() {
return gender;
}public void setGender(String gender) {
this.gender = gender;
}@Column(name="age")
public Integer getAge() {
return age;
}public void setAge(Integer age) {
this.age = age;
}@Column(name="addr")
public String getAddr() {
return addr;
}public void setAddr(String addr) {
this.addr = addr;
}@Column(name="email")
public String getEmail() {
return email;
}public void setEmail(String email) {
this.email = email;
}@Transient
public Integer getBirthYear() {
return new Integer(2008-age);
}public void setBirthYear(Integer age) {
this.birthYear = new Integer(2008-age);
}
} |
其中，birthYear不是数据库中的字段，使用JPA的@Transient注解，在映射的时候，会忽略掉该成员。
持久层DAO接口如下：
package org.shirdrn.dao; import java.util.List; import org.shirdrn.entity.MyUser; import org.springframework.transaction.annotation.Transactional; @Transactional
public interface MyUserDAO {
public void createMyUser(MyUser myUser);
public void deleteMyUser(MyUser myUser);
public void updateMyUser(MyUser myUser);
public List |
这里，使用了JPA注解，声明事务。
DAO实现类，如下所示：
package org.shirdrn.dao.impl; import java.util.List; import org.shirdrn.dao.MyUserDAO; import org.shirdrn.entity.MyUser; import org.springframework.orm.jpa.support.JpaDaoSupport; public class MyUserDAOImpl extends JpaDaoSupport implements MyUserDAO {public void createMyUser(MyUser myUser) {
getJpaTemplate().persist(myUser);
}public void deleteMyUser(MyUser myUser) {
MyUser dbMyUser = getJpaTemplate().find(MyUser.class, myUser.getId());
getJpaTemplate().remove(dbMyUser);
}public void updateMyUser(MyUser myUser) {
MyUser dbMyUser = getJpaTemplate().find(MyUser.class, myUser.getId());
if(myUser.getUserName() != null){
dbMyUser.setUserName(myUser.getUserName());
}
if(myUser.getAddr() != null){
dbMyUser.setAddr(myUser.getAddr());
}
getJpaTemplate().merge(dbMyUser);
}@SuppressWarnings("unchecked")
public List@SuppressWarnings("unchecked")
public List |
因为继承了JpaDaoSupport，索引需要获取一个JpaTemplate来实现访问数据库，在Spring的配置文件中要注入一个org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean。
Spring的配置文件applicationContext.xml的内容如下所示：
