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框架目的是简化操作,提高代码利用率,jdbc方式还有很多欠缺,因此不是框架所需要的,于是springjpa挺身而出,它不仅有springjdbc的集成性,而且具有简化sql,实现分页等等比较牛逼的功能。
其实现类似于spring jdbc,下面粘出其配置文件
- <?xml version="1.0" encoding="UTF-8" ?>
- <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
- xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
- http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
- http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
- http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
- <!--1 配置数据源-->
- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
- <property name="driverClassName" value="com.mysql.jdbc.Driver" />
- <property name="username" value="root" />
- <property name="password" value="" />
- <property name="url" value="jdbc:mysql:///db_name" />
- </bean>
- <!--2 配置EntityManagerFactory-->
- <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
- <property name="dataSource" ref="dataSource" />
- <property name="jpaVendorAdapter">
- <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
- />
- </property>
- <property name="packagesToScan" value="com.imooc" />
- <property name="jpaProperties">
- <props>
- <prop key="hibernate.ejb.naming_strategy">
- org.hibernate.cfg.ImprovedNamingStrategy
- </prop>
- <prop key="hibernate.dialect">
- org.hibernate.dialect.MySQL5InnoDBDialect
- </prop>
- <prop key="hibernate.show_sql">
- true
- </prop>
- <prop key="hibernate.format_sql">
- true
- </prop>
- <prop key="hibernate.hbm2ddl.auto">
- update
- </prop>
- </props>
- </property>
- </bean>
- <!--3 配置事务管理器-->
- <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
- <property name="entityManagerFactory" ref="entityManagerFactory" />
- </bean>
- <!--4 配置支持注解的事务-->
- <tx:annotation-driven transaction-manager="transactionManager" />
- <!--5 配置spring data-->
- <jpa:repositories base-package="com.repository" entity-manager-factory-ref="entityManagerFactory"
- />
- <context:component-scan base-package="com.beans" />
- </beans>
此时需要特殊注意的是注释1以及注释5: 自动扫描找到repositories;扫描bean类
会自动扫描到@Entity(doamin)和@RepositoryDefinition()注解
描到@Entity: 这个实体类会对应数据库一个表(此表没有回自动创建,spring jpa的独特功能),作为bean使用
- @Entity
- public class Student{
- private Integer id;
- private String name;
- private Integer age;
- @GeneratedValue
- @Id
- public Integer getId() {
- return id;
- }
- public void setId(Integer id) {
- this.id = id;
- }
- @Column(length = 20)
- public String getName() {
- return name;
- }
- public void setName(String name) {
- this.name = name;
- }
- public Integer getAge() {
- return age;
- }
- public void setAge(Integer age) {
- this.age = age;
- }
- }
描到@RepositoryDefinition(如果不用RepositoryDefinition直接继承Repository类也可以实现),使用这个注解可以实现StudentRepositor接口(接口名自己定义,一般取bean的名字),使用时只有继承这个接口就可以。而且这个类还可以实现sql的封装下面列出我写的几个实现
- @RepositoryDefinition(domainClass = Student.class, idClass = Integer.class)
- public interface StudentRepository {
- public Student findByName(String name);
- // where name like ?% and age <?
- public List<Student> findByNameStartingWithAndAgeLessThan(String name, Integer age);
- // where name like %? and age <?
- public List<Student> findByNameEndingWithAndAgeLessThan(String name, Integer age);
- // where name in (?,?....) or age <?
- public List<Student> findByNameInOrAgeLessThan(List<String> names, Integer age);
- // where name in (?,?....) and age <?
- public List<Student> findByNameInAndAgeLessThan(List<String> names, Integer age);
- @Query("select o from Student o where id=(select max(id) from Student t1)")
- public Student getEmployeeByMaxId();
- @Query("select o from Student o where o.name=?1 and o.age=?2")
- public List<Student> queryParams1(String name, Integer age);
- @Query("select o from Student o where o.name=:name and o.age=:age")
- public List<Student> queryParams2(@Param("name")String name, @Param("age")Integer age);
- @Query("select o from Student o where o.name like %?1%")
- public List<Student> queryLike1(String name);
- @Query("select o from Student o where o.name like %:name%")
- public List<Student> queryLike2(@Param("name")String name);
- @Query(nativeQuery = true, value = "select count(1) from Student")
- public long getCount();
- //Modifying实现了事物
- @Modifying
- @Query("update Student o set o.age = :age where o.id = :id")
- public void update(@Param("id")Integer id, @Param("age")Integer age);
- }
repository查询方法定义规则和使用
接下来只要实现EmployeeRepository接口就可以愉快的curd了。
- //根据上下文获取
- ctx = new ClassPathXmlApplicationContext("beans-new.xml");
- studentRepository = ctx.getBean(StudentRepository.class);
- Student Student = studentRepository.findByName("zhangsan");
- System.out.println("id:" + Student.getId()
- + " , name:" + Student.getName()
- + " ,age:" + Student.getAge());
- }
那么如何实现分页呢?很简单,只要StudentRepository类继承PagingAndSorting接口就行了
- public interface StudentRepository extends PagingAndSortingRepository {}
操作注意Pageable类需要引入jpa包中的Pageable类
- //根据上下文获取
- ctx = new ClassPathXmlApplicationContext("beans-new.xml");
- studentRepository = ctx.getBean(StudentRepository.class);
- Pageable pageable = new PageRequest(0, 5);
- Student Student = studentRepository.findAll(pageable);
java学习之spring data jpa
odi idclass ans transacti auto cnblogs packages ndb user
原文:http://www.cnblogs.com/libinblogs/p/7872418.html
来源: http://www.bubuko.com/infodetail-2402794.html