JPA 教程 实例

实体类：

 

package test.entityjpa;

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

/**
 * JesonTest entity.
 * 
 * @author MyEclipse Persistence Tools
 */
@Entity
@Table(name = "JESON_TEST")
public class JesonTest implements java.io.Serializable {

    // Fields
    private Integer userid;
    private String name;
    private String password;

    // Constructors
    /** default constructor */
    public JesonTest() {
    }

    /** minimal constructor */
    public JesonTest(Integer userid) {
        this.userid = userid;
    }

    /** full constructor */
    public JesonTest(Integer userid, String name, String password) {
        this.userid = userid;
        this.name = name;
        this.password = password;
    }

    // Property accessors
    @Id
    @Column(name = "USERID", unique = true, nullable = false, insertable = true, updatable = true, precision = 20, scale = 0)
    public Integer getUserid() {
        return this.userid;
    }

    public void setUserid(Integer userid) {
        this.userid = userid;
    }

    @Column(name = "NAME", unique = false, nullable = true, insertable = true, updatable = true)
    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Column(name = "PASSWORD", unique = false, nullable = true, insertable = true, updatable = true, length = 10)
    public String getPassword() {
        return this.password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

 配置文件：

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

	<persistence-unit name="jpaDemo" transaction-type="RESOURCE_LOCAL">
		<provider>org.hibernate.ejb.HibernatePersistence</provider>

		<!-- 这里的class指向我们的pojo类 -->
		<class>test.entityjpa.JesonTest</class>
		<exclude-unlisted-classes>true</exclude-unlisted-classes>

		<properties>
			<property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver" />
			<property name="hibernate.connection.url" value="jdbc:oracle:thin:@i18nserver:1521:i18n" />
			<property name="hibernate.connection.username" value="wpeng_8g" />
			<property name="hibernate.connection.password" value="exigen" />
			<property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect" />
			<property name="hibernate.show_sql" value="true" />
			<property name="minPoolSize" value="5" />
			<property name="initialPoolSize" value="10" />
			<property name="maxPoolSize" value="200" />
			<property name="idleConnectionTestPeriod" value="120" />
			<property name="acquireIncrement" value="10" />
			<property name="checkoutTimeout" value="3600" />
			<property name="numHelperThreads" value="4" />
			<property name="maxStatements" value="400" />
			<property name="maxStatementsPerConnection" value="20" />
			<property name="maxIdleTime" value="180" />
			<property name="acquireRetryAttempts" value="30" />
		</properties>
	</persistence-unit>
</persistence>

 测试类：

package test.entityjpa;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

public class TestCase {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        EntityManagerFactory factory = Persistence.createEntityManagerFactory("jpaDemo");
        EntityManager manager =  factory.createEntityManager();
        EntityTransaction tran = manager.getTransaction();
        tran.begin();
        JesonTest ower = new JesonTest();
        ower.setUserid(1);
        ower.setPassword("exigen");
        ower.setName("wpeng_8g");
        manager.persist(ower);
        tran.commit();
        System.out.println(ower.getName());
    }

}