Spring Data JPA

<?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:aop="http://www.springframework.org/schema/aop"
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-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
">
<context:component-scan base-package="cn.javass">
<context:exclude-filter type="annotation“ expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<aop:aspectj-autoproxy proxy-target-class="true"/>
<!-- 开启注解事务 只对当前配置文件有效 -->
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>
    <jpa:repositories
            base-package="cn.javass"
            repository-impl-postfix="Impl"
            entity-manager-factory-ref="entityManagerFactory"
            transaction-manager-ref="transactionManager">
    </jpa:repositories>   
     <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="packagesToScan" value="cn.javass"/>
        <property name="persistenceProvider">
            <bean class="org.hibernate.ejb.HibernatePersistence"/>
        </property>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="generateDdl" value="false"/>
                <property name="database" value="MYSQL"/>
                <property name="databasePlatform" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
                <property name="showSql" value="true"/>
            </bean>
        </property>
        <property name="jpaDialect">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>
        </property>
        <property name="jpaPropertyMap">
            <map>
                <entry key="hibernate.query.substitutions" value="true 1, false 0"/>
                <entry key="hibernate.default_batch_fetch_size" value="16"/>
                <entry key="hibernate.max_fetch_depth" value="2"/>
                <entry key="hibernate.generate_statistics" value="true"/>
                <entry key="hibernate.bytecode.use_reflection_optimizer" value="true"/>
                <entry key="hibernate.cache.use_second_level_cache" value="false"/>
                <entry key="hibernate.cache.use_query_cache" value="false"/>
            </map>
        </property>
    </bean>
<!--事务管理器配置-->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>
 
<bean name="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName"><value>org.gjt.mm.mysql.Driver</value></property>
<property name="url"><value>jdbc:mysql://localhost:3306/cc?useUnicode=true&amp;characterEncoding=UTF-8</value></property>
<property name="username"> <value>root</value> </property>
<property name="password" value="cc"/>
</bean>
</beans>

第四章：客户化扩展JpaRepository

public class UserRepositoryImpl {  
    @PersistenceContext  
    private EntityManager em;     
    public Page<Object[]> getByCondition(UserQueryModel u){  
String hql = "select o.uuid,o.name from UserModel o where 1=1 and o.uuid=:uuid";  
        Query q = em.createQuery(hql);  
        q.setParameter("uuid", u.getUuid());          
        q.setFirstResult(0);  
        q.setMaxResults(1);       
Page<Object[]> page = new PageImpl<Object[]>(q.getResultList(),new PageRequest(0,1),3);   
        return page;  
}}  

Specification<UserModel> spec = new Specification<UserModel>() {  
public Predicate toPredicate(Root<UserModel> root,  
        CriteriaQuery<?> query, CriteriaBuilder cb) {  
    List<Predicate> list = new ArrayList<Predicate>();  
          
    if(um.getName()!=null && um.getName().trim().length()>0){  
        list.add(cb.like(root.get("name").as(String.class), "%"+um.getName()+"%"));  
    }  
    if(um.getUuid()>0){  
        list.add(cb.equal(root.get("uuid").as(Integer.class), um.getUuid()));  
    }  
    Predicate[] p = new Predicate[list.size()];  
    return cb.and(list.toArray(p));  
}  
};  

Specification<UserModel> spec = new Specification<UserModel>() {  
    public Predicate toPredicate(Root<UserModel> root,  
            CriteriaQuery<?> query, CriteriaBuilder cb) {  
        Predicate p1 = cb.like(root.get("name").as(String.class), "%"+um.getName()+"%");  
        Predicate p2 = cb.equal(root.get("uuid").as(Integer.class), um.getUuid());  
        Predicate p3 = cb.gt(root.get("age").as(Integer.class), um.getAge());  
        //把Predicate应用到CriteriaQuery中去,因为还可以给CriteriaQuery添加其他的功能，比如排序、分组啥的  
        query.where(cb.and(p3,cb.or(p1,p2)));  
        //添加排序的功能  
        query.orderBy(cb.desc(root.get("uuid").as(Integer.class)));  
          
        return query.getRestriction();  
    }  
};