标签：等等 length ddl pat sys where count mysql dag
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 );
标签：等等 length ddl pat sys where count mysql dag
原文地址：http://www.cnblogs.com/libinblogs/p/7872418.html
