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JPA & SpringData 之 SpringData

时间：2018-05-11 23:53:58      阅读：332      评论：0      收藏：0      [点我收藏+]

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1 Spring Data概述

  • Spring Data：Spring的一个子项目。用于简化数据库的访问，支持NOSQL和关系数据库。其主要目标就是使得数据库的访问变得方便和快捷。
  • Spring Data项目所支持NOSQL存储：
    • MongoDB
    • Neo4j
    • Redis
    • Hbase
  • SpringData项目所支持的关系数据库存储技术：
    • JDBC
    • JPA　　

 

2 JPA Spring Data

  • JPA Spring Data：致力于减少数据访问层的开发量。开发者唯一要做的，就只是声明持久层的接口，其他的交给Spring Data JPA来帮你完成！
  • 框架是怎么来帮我们来完成业务逻辑的啊？比如，当有一个findByUserById()这样一个方法的声明，大致就可以判断出这是一个根据给定条件的ID查询出满足条件的User对象。Spring Data JPA做的便是规范方法的名字，根据符合规范的名字来确定方法需要实现什么样的逻辑。

 

3 Spring Data的HelloWorld

  • ①加入mysql、Spring和JPA的jar包，当然还需要导入spring data的jar包。
  • ②在applicationContext.xml中配置springdata
<?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">

    <context:component-scan base-package="com.xuweiwei"></context:component-scan>

    <context:property-placeholder location="classpath*:db.properties"></context:property-placeholder>

    <!-- 配置c3p0数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="password" value="${jdbc.password}"></property>
        
    </bean>

    <!-- 配置EntityManager -->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <!-- 配置JPA的产品提供商 -->
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"></bean>
        </property>
        <property name="packagesToScan" value="com.xuweiwei.springdata.entity"></property>

        <property name="jpaProperties">
            <props>
                <!--
                    开启驼峰命名：此属性很好，不过注意的是这个是Hibernate4.x支持的，Hibernate5.x需要修改
                    比如：LastName是java类中的属性，对应数据库中的表的列是last_name
                -->
                <prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            </props>
        </property>

    </bean>

    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>
    <!-- 开启注解式的事务 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <!-- 配置Spring Data -->
    <!--
        加入jpa的命名空间
            其中base-package：用来扫描Repository Bean所在的package
    -->
    <jpa:repositories base-package="com.xuweiwei.springdata.repository" entity-manager-factory-ref="entityManagerFactory"/>

</beans>
  • 顺便引入db.properties
jdbc.user=root
jdbc.password=root
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///jpa
  • ③声明持久层的接口，该接口继承Repository。Repository是一个标记型的接口，不包含任何的方法
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person, Integer> {

    Person getByLastName(String lastName);
}
  • ④在接口中声明需要的方法，当然，你可能需要新建实体类
package com.xuweiwei.springdata.entity;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
@Entity
@Table
public class Person  {
    private String lastName;
    private Integer id;
    private String email;

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "Person{" +
                "lastName=‘" + lastName + ‘\‘‘ +
                ", id=" + id +
                ", email=‘" + email + ‘\‘‘ +
                ‘}‘;
    }

}
  • 测试
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import javax.sql.DataSource;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context = null;

    static{
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    @Test
    public void testDataSource(){
        DataSource dataSource = (DataSource) context.getBean("dataSource");
        System.out.println(dataSource);
    }

    @Test
    public void testCreateTable(){

    }

    @Test
    public void testHelloWorldSpringData(){
        PersonRepository personRepository = context.getBean(PersonRepository.class);
        Person person = personRepository.getByLastName("xuweiwei");
        System.out.println(person);
    }
}

 

4 Repository接口

  • ①Repository接口是一个空接口，就是一个标记接口。
  • ②如果我们定义的接口继承了Repository接口，则该接口会被IOC容器识别为一个Repository Bean，纳入到IOC容器中，进而可以在该接口中定义满足一定规范的方法。
  • ③实际上，也可以通过注解@RepositoryDefinition来替代继承Repository接口
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.RepositoryDefinition;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
@RepositoryDefinition(domainClass = Person.class,idClass = Integer.class)
public interface PersonRepository  {

    Person getByLastName(String lastName);
}

 

  • 总结Repository接口的使用方法：
    • ①开发者需要继承Repository接口
    • ②开发者不需要继承Repository接口，但是需要在持久层接口上使用@RepositoryDefinition注解，并为其指定domainClass和idClass属性。　　

技术分享图片

  • 基础的Repository提供了最基本的数据访问功能，其几个子接口则扩展了一些功能。它们的继承关系如下：
    • Repository：仅仅是一个标识，表明任何继承它的均为仓库接口类。
    • CRUDRepository：继承Repository，实现了一组CRUD相关的方法。
    • PaginAndSortingRepository：继承CRUDRepository，实现了一组分页排序相关的方法。
    • JpaRepository：继承PagingAndSortingRepository，实现一组JPA相关的方法。
    • 自定义的XxxxRepository需要继承JPARepository，这样的XxxxRepository接口就具备了通用的数据访问控制层的能力。
    • JpaSpecificationExecutor：不属于Repository体系，实现一组JPA Criteria查询相关的方法。　　

 

5 SpringData中定义方法的规范

  • ①不是随便定义的，需要按照一定的规范。
  • ②查询方法需要以read|find|get开头
  • ③涉及条件查询的时候，条件的属性用条件关键字连接
  • ④注意，条件属性需要大写
  • ⑤支持属性的级联查询，如果当前类有符合条件的属性，则优先使用，而不是级联属性，如果需要使用级联属性，则属性之间使用_连接。

 

5.1 准备工作

  • 导入jar包，或用maven或gradle构建项目。

  • 新建db.properties
技术分享图片 
jdbc.user=root
jdbc.password=root
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///jpa
View Code
  • 新建appliationContext.xml
技术分享图片 
<?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">

    <context:component-scan base-package="com.xuweiwei"></context:component-scan>

    <context:property-placeholder location="classpath*:db.properties"></context:property-placeholder>

    <!-- 配置c3p0数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="password" value="${jdbc.password}"></property>
        
    </bean>

    <!-- 配置EntityManager -->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <!-- 配置JPA的产品提供商 -->
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"></bean>
        </property>
        <property name="packagesToScan" value="com.xuweiwei.springdata.entity"></property>

        <property name="jpaProperties">
            <props>
                <!--
                    开启驼峰命名：此属性很好，不过注意的是这个是Hibernate4.x支持的，Hibernate5.x需要修改
                    比如：LastName是java类中的属性，对应数据库中的表的列是last_name
                -->
                <prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            </props>
        </property>

    </bean>

    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>
    <!-- 开启注解式的事务 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <!-- 配置Spring Data -->
    <!--
        加入jpa的命名空间
            其中base-package：用来扫描Repository Bean所在的package
    -->
    <jpa:repositories base-package="com.xuweiwei.springdata.repository" entity-manager-factory-ref="entityManagerFactory"/>

</beans>
View Code
  • 新建Person.java实体类
package com.xuweiwei.springdata.entity;

import javax.persistence.*;
import java.util.Date;

/**
 * @author 许威威
 * @description:
 *  <dl>
 *      <dt>
 *          注意
 *      </dt>
 *      <dd>
 *          此处我之所以不使用@Column来自定义数据库列的名称，是因为我使用的是Hibernate的驼峰规则，在applicationContext.xml中查看到
 *      </dd>
 *  </dl>
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
@Entity
@Table(name="person")
public class Person {

    private Integer id;
    private String lastName;
    private String email;
    private Integer age;
    private Date birthday;
    private Date createTime;

    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
    @Temporal(TemporalType.DATE)
    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    @Temporal(TemporalType.TIMESTAMP)
    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
}
  • 新建测试类，使用Hibernate底层的ddl功能，来生成表
package com.xuweiwei.springdata.test;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
    }
    @Test
    public void testCreateTable(){

    }

}
  • 增加一些数据
insert  into `person`(`id`,`age`,`birthday`,`create_time`,`email`,`last_name`) values 
(1,8,‘2018-05-02‘,‘2018-05-11 19:30:23‘,‘aa@qq.com‘,‘sd‘),
(2,34,‘2018-04-01‘,‘2018-05-11 19:30:26‘,‘dd@qq.com‘,‘dafd‘),
(3,32,‘2018-04-03‘,‘2018-05-03 19:30:28‘,‘ds@qq.com‘,‘fdaf‘),
(4,56,‘2018-04-05‘,‘2018-05-03 19:30:30‘,‘dadf@qq.com‘,‘fda‘),
(5,34,‘2018-04-07‘,‘2018-05-11 19:30:33‘,‘vdf@qq.com‘,‘fda‘),
(6,23,‘2018-01-10‘,‘2018-05-11 19:30:34‘,‘dadfd@qq.com‘,‘fda‘),
(7,73,‘2017-04-10‘,‘2018-05-11 19:30:37‘,‘da@qq.com‘,‘fda‘),
(8,8,‘2018-02-06‘,‘2018-05-11 19:30:39‘,‘da@qq.com‘,‘fa‘),
(9,9,‘2018-04-20‘,‘2018-05-11 19:30:41‘,‘da@qq.com‘,‘fa‘),
(10,33,‘2017-02-15‘,‘2018-05-11 19:30:43‘,‘fgs@qq.com‘,‘f‘),
(11,22,‘2017-07-25‘,‘2018-05-11 19:30:44‘,‘da@qq.com‘,‘fda‘),
(12,12,‘2016-06-22‘,‘2018-05-11 19:30:46‘,‘we@qq.com‘,‘da‘),
(13,27,‘2010-06-16‘,‘2018-05-11 19:30:49‘,‘ewe@qq.com‘,‘fda‘),
(14,56,‘2000-06-06‘,‘2018-05-11 19:30:51‘,‘ewe@qq.com‘,‘fda‘),
(15,79,‘2009-06-09‘,‘2018-05-11 19:30:52‘,‘ewe@qq.com‘,‘dfa‘);

 

5.2 支持的关键字

  • 直接在接口中定义查询方法，如果是符合规范的，可以不用写实现，目前支持的关键字的写法如下所示：

技术分享图片

技术分享图片

 

  • 示例：And，就相当于where x.last_name = ? and x.age = ?   
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {
    /**
     * And关键字
     * @param lastName
     * @param age
     * @return
     */
    List<Person> getByLastNameAndAge(String lastName,Integer age);
}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){

    }
    @Test
    public void testAnd(){
        List<Person> persons = personRepository.getByLastNameAndAge("sd", 8);
        for (Person person : persons) {
            System.out.println(person);
        }
    }
}
  • 示例：Or，就相当于where x.last_name =? or x.age = ?
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {
    /**
     * 关键字 Or
     * @param lastName
     * @param email
     * @return
     */
    List<Person> getByLastNameOrEmail(String lastName,String email);
}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){

    }
    @Test
    public void testOr(){
        List<Person> persons = personRepository.getByLastNameOrEmail("fa", "da@qq.com");
        for (Person person : persons) {
            System.out.println(person);
        }
    }



}
  • 示例：Between，相当于where x.birthday between ? and ?
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

import java.util.Date;
import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {
    /**
     * 关键字：between
     * @param startTime
     * @param endTime
     * @return
     */
    List<Person> getByBirthdayBetween(Date startTime,Date endTime);
}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){

    }
    @Test
    public void testBetween() throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date startTime = sdf.parse("2011-11-11");
        List<Person> persons = personRepository.getByBirthdayBetween(startTime, new Date());
        for (Person person : persons) {
            System.out.println(person);
        }
    }



}
  • 示例：LessThan，相当于where x.age < ?
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:LessThan
     * @param age
     * @return
     */
    List<Person> getByAgeLessThan(Integer age);



}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.text.ParseException;
import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){

    }
    @Test
    public void testBetween() throws ParseException {
        List<Person> personList = personRepository.getByAgeLessThan(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }



}
  • 示例：LessThanEqual，相当于where x.age <= ?
package com.xuweiwei.springdata.repository;
import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;
import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:LessThanEqual
     * @param age
     * @return
     */
    List<Person> getByAgeLessThanEqual(Integer age);
}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.text.ParseException;
import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByAgeLessThanEqual(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：GreaterThan
package com.xuweiwei.springdata.repository;
import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;
import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:GreaterThan
     * @param age
     * @return
     */
    List<Person> getByAgeGreaterThan(Integer age);
}
package com.xuweiwei.springdata.test;

import com.xuweiwei.springdata.entity.Person;
import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.text.ParseException;
import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByAgeGreaterThan(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：GreaterThanEqual，相当于where x.age >= ?
package com.xuweiwei.springdata.repository;
import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;
import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:GreaterThanEqual
     * @param age
     * @return
     */
    List<Person> getByAgeGreaterThanEqual(Integer age);
}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByAgeGreaterThanEqual(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：Before，相当于where x.age < ?
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:Before
     * @param age
     * @return
     */
    List<Person> getByAgeBefore(Integer age);
}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByAgeBefore(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：After，相当于where x.age > ?
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:Before
     * @param age
     * @return
     */
    List<Person> getByAgeAfter(Integer age);
}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByAgeAfter(100);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • IsNull，相当于where x.last_name is null
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:IsNull
     * @param
     * @return
     */
    List<Person> getByLastNameIsNull();
}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByLastNameIsNull();
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：LsNotNull，相当于where x.age is not null
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:IsNotNull
     * @param
     * @return
     */
    List<Person> getByLastNameIsNotNull();
}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByLastNameIsNotNull();
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 示例：
    • Like，相当于where x.last_name like ?，精确匹配
    • NotLike，相当于where x.last_name not like ? ，精确匹配
    • StartingWith，相当于where x.last_name like ?，模糊匹配，会在将参数设置进去的时候，在左边加上%
    • EndingWith，相当于where x.last_name like ?，模糊匹配，会在将参数设置进去的时候，在后边加上%
    • Containing，相当于where x.last_name like ? ，模糊匹配，会在将参数设置进去的时候，在左右两边加上%
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:Like
     * @param
     * @return
     */
    List<Person> getByLastNameLike(String lastName);
    /**
     * 关键字:NotLike
     * @param
     * @return
     */
    List<Person> getByLastNameNotLike(String lastName);

    /**
     * 关键字:StartingWith
     * @param
     * @return
     */
    List<Person> getByLastNameStartingWith(String lastName);
    /**
     * 关键字:EndingWith
     * @param
     * @return
     */
    List<Person> getByLastNameEndingWith(String lastName);
    /**
     * 关键字:Containing
     * @param
     * @return
     */
    List<Person> getByLastNameContaining(String lastName);


}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByLastNameLike("fd");
        for (Person person : personList) {
            System.out.println(person);
        }

        personList = personRepository.getByLastNameNotLike("fd");
        for (Person person : personList) {
            System.out.println(person);
        }
        personList = personRepository.getByLastNameStartingWith("fd");
        for (Person person : personList) {
            System.out.println(person);
        }
        personList = personRepository.getByLastNameEndingWith("a");
        for (Person person : personList) {
            System.out.println(person);
        }
        personList = personRepository.getByLastNameContaining("d");
        for (Person person : personList) {
            System.out.println(person);
        }


    }
}
  • 示例：Not，相当于where x.last_name <> ? 或where x.last_name != ?
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:Not
     * @param
     * @return
     */
    List<Person> getByLastNameNot(String lastName);


}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.getByLastNameNot("fa");
        for (Person person : personList) {
            System.out.println(person);
        }


    }
}
  • 示例：in，相当于where x.age in (12,3,4)
package com.xuweiwei.springdata.repository;
        import com.xuweiwei.springdata.entity.Person;
        import org.springframework.data.repository.Repository;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    /**
     * 关键字:In
     * @param
     * @return
     */
    List<Person> readByAgeIn(List<Integer> age);


}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
        import org.junit.Test;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.support.ClassPathXmlApplicationContext;
        import java.text.ParseException;
        import java.util.Arrays;
        import java.util.List;
/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void testPrimary() throws ParseException {
        List<Person> personList = personRepository.readByAgeIn(Arrays.asList(34,9,12));
        for (Person person : personList) {
            System.out.println(person);
        }


    }
}
  • 示例：NotIn，相当于where x.age not in(2,3,4)
    • 代码：略
  • 示例：TRUE，相当于where x.active = true ，遗憾的是，MySQL不支持boolean类型的字段。
  • 示例：FALSE，相当于where x.active =false，遗憾的是，MySQL不支持Boolean类型的字段。

 

  • SpringData会有坑的，记载如下，就是上面的第5点，支持属性的级联查询，如果当前类有符合条件的属性，则优先使用，而不是级联属性，如果需要使用级联属性，则属性之间使用_连接。
  • 以下面的场景为例，一个地区有许多人们，所以地区是主表，而人们是从表，人们表有一个外键。
    • Address,java　　
package com.xuweiwei.springdata.entity;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
@Table
@Entity
public class Address {
    private Integer id;
    private String province;
    private String city;

    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getProvince() {
        return province;
    }

    public void setProvince(String province) {
        this.province = province;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }
}
package com.xuweiwei.springdata.entity;

import javax.persistence.*;
import java.util.Date;

/**
 * @author 许威威
 * @description:
 *  <dl>
 *      <dt>
 *          注意
 *      </dt>
 *      <dd>
 *          此处我之所以不使用@Column来自定义数据库列的名称，是因为我使用的是Hibernate的驼峰规则，在applicationContext.xml中查看到
 *      </dd>
 *  </dl>
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
@Entity
@Table(name="person")
public class Person {

    private Integer id;
    private String lastName;
    private String email;
    private Integer age;
    private Date birthday;
    private Date createTime;

    private Address address;

    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
    @Temporal(TemporalType.DATE)
    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    @Temporal(TemporalType.TIMESTAMP)
    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
    @JoinColumn(name="address_id")
    @ManyToOne
    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }
}
package com.xuweiwei.springdata.repository;

import com.xuweiwei.springdata.entity.Person;
import org.springframework.data.repository.Repository;

import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public interface PersonRepository extends Repository<Person,Integer> {

    List<Person> getByAddressId(Integer id);

}
package com.xuweiwei.springdata.test;

        import com.xuweiwei.springdata.entity.Person;
        import com.xuweiwei.springdata.repository.PersonRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

        import java.util.List;

/**
 * @author 许威威
 * @description:
 * @motto 代码虐我千百遍，我视代码如初恋
 * @created date :2018-05-11
 * @modified by:
 */
public class SpringDataTest {
    private static ApplicationContext context  = null;
    private static PersonRepository personRepository = null;
    static {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
        personRepository = context.getBean(PersonRepository.class);
    }
    @Test
    public void testCreateTable(){
    }
    @Test
    public void test(){
        List<Person> personList = personRepository.getByAddressId(1);
        for (Person person : personList) {
            System.out.println(person);
        }
    }
}
  • 这样，貌似是没有问题的，但是如果我在Person.java中也增加addressId属性，那么情况就会如下所示。

 

JPA & SpringData 之 SpringData

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原文地址：https://www.cnblogs.com/xuweiweiwoaini/p/9024813.html
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