Spring data jpa 入门环境搭建

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springdata -jpa模块入门环境搭建

1、 导入需要的jar包(这里以maven为准)
只需要导入三个maven坐标 mysql、hibernate、springdata -jpa

<!--MySQL Driver-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>

        <!--spring data jpa-->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.8.0.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>4.3.6.Final</version>
        </dependency>

2、xml文件的配置

<?xml version="1.0" encoding="UTF-8"?>

<!--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="12345"/>
    <property name="url" value="jdbc:mysql://localhost/demo"/>
</bean>

<!--2:配置EntityManagerFactory  通过这个类管理实体类与数据库-->
<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>
    <!-- 告诉实体类的位置 -->
    <property name="packagesToScan" value="com.mc"/>

    <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:配置事物管理器-->
<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.mc" entity-manager-factory-ref="entityManagerFactory"/>
<!--对这个包下的类进行注解扫描-->
<context:component-scan base-package="com.mc"/>

3、编写实体类
package com.mc.entrty;

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

@Entity // 告诉springdata 对这个类进行建表
public class User {

private Integer id;
private String name;
private  Integer age;

@[e-mail] // 这个字段是id 与自动增长
public Integer getId() {
    return id;
}

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

@Column(length = 20,nullable = false)
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;
}

@Override
public String toString() {
    return "User{" +
            "id=" + id +
            ", name='" + name + '\'' +
            ", age=" + age +
            '}';
}

}

4、编写一个接口并继承jpa的核心接口
package com.mc.repository;

import com.mc.entrty.User;
import org.springframework.data.repository.Repository;

public interface UserRepository extends Repository<User,Integer> {
public User findByName(String name);
}

5、测试就ok了

package com.mc.test;

import com.mc.entrty.User;
import com.mc.repository.UserRepository;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Demo {

@Test
public void testUserRepository()
{
    ApplicationContext ctx = new ClassPathXmlApplicationContext("bean.xml");
    UserRepository userRepository = ctx.getBean(UserRepository.class);
    User user = userRepository.findByName("zs");
    System.out.println(user);
}

}

这是springdata -jpa的入门程序 、希望能帮助向我一样的初学者快速的人门、也同时希望和大家一起讨论进步，入门搭建好之后就可以拓展其他jpa的使用了