JPA教程 - JPA Spring HSQL开发环境设置示例

JPA教程 – JPA Spring HSQL开发环境设置示例

以下部分显示如何设置开发环境用于使用Spring JPA和HSQL数据库开发JPA应用程序。

单击以下链接下载文件。

Download JPA_Env_Setup.zip

POM文件

下面的代码列出了开发所需的Maven依赖JPA应用程序。

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.w3cschool.jpa</groupId>
  <artifactId>Java2sExamples</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>Java2sExamples_JPA</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>4.2.0.Final</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>3.2.2.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>3.2.2.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>3.2.2.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.hsqldb</groupId>
      <artifactId>hsqldb</artifactId>
      <version>2.3.2</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

弹簧配置

以下代码来自applicationContext.xml。

?<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
  xmlns:security="http://www.springframework.org/schema/security"
  xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">

  <tx:annotation-driven />
  <context:annotation-config />

  <bean id="personDao" class="cn.w3cschool.common.PersonDaoImpl" />

  <bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName">
      <value>org.hsqldb.jdbcDriver</value>
    </property>
    <property name="url">
      <value>jdbc:hsqldb:mem:mydatabase</value>
    </property>
    <property name="username">
      <value>sa</value>
    </property>
    <property name="password">
      <value></value>
    </property>
  </bean>

  <bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="persistenceUnitName" value="jpaData" />
    <property name="jpaVendorAdapter">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
    </property>
    <property name="jpaProperties">
      <props>
        <prop key="hibernate.dialect">org.hibernate.dialect.HSQLDialect</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>

  <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
  </bean>

</beans>

以下代码来自persistence.xml。

?<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
    xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">

  <persistence-unit name="jpaData" />

</persistence>

弹簧配置…

以下代码来自persistence.xml。…

package cn.w3cschool.common;

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

@Entity
public class Person {
  @Id
  @GeneratedValue
  private Long id;
  private String name;
  private String surname;

  public Person() {}

  public Person(String name, String surname) {
    this.name = name;
    this.surname = surname;
  }

  public Long getId() {
    return id;
  }
  public void setId(Long id) {
    this.id = id;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public String getSurname() {
    return surname;
  }
  public void setSurname(String surname) {
    this.surname = surname;
  }
  @Override
  public String toString() {
    return "Person [id=" + id + ", name=" + name + ", surname=" + surname + "]";
  }
}

DAO类

下面的代码来自PersonDaoImpl.java。

package cn.w3cschool.common;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.transaction.annotation.Transactional;

@Transactional
public class PersonDaoImpl {

  @PersistenceContext
  private EntityManager em;

  public Long save(Person person) {
    em.persist(person);
    return person.getId();
  }

  public List<Person>getAll() {
    return em.createQuery("SELECT p FROM Person p", Person.class).getResultList();
  }

}

主类

以下代码来自App.java。

package cn.w3cschool.common;

import java.util.List;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App {

  public static void main(String[] args) {
    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
        "applicationContext.xml");
    PersonDaoImpl dao = (PersonDaoImpl) context.getBean("personDao");

    Person peter = new Person("XML", "HTML");
    Person nasta = new Person("Java", "SQL");

    dao.save(peter);
    dao.save(nasta);

    List<Person> persons = dao.getAll();
    for (Person person : persons) {
      System.out.println(person);
    }
    context.close();
  }
}

Download JPA_Env_Setup.zip

运行应用程序

使用以下命令运行应用程序。

mvn clean compile exec:java -Dexec.mainClass="cn.w3cschool.common.App"

上面的代码生成以下结果。