(六)- 构建Hibernate项目

前面我们使用Maven构建了Struts2项目,这里我们来试一下Hibernate项目:

ps: 昨天晚上没有整明白,例子也一直有问题,就没有完成博客,早上起来才明白错在哪大笑

这里的例子,大体框架应该是正确的,但是,对于Maven的很多约定都没有掌握,估计包的命名都不是非常好,等以后,理解深刻了再改吧微笑

1. 构建一个基本的Web项目

这里请参考前面的博客,一样的

2. 添加依赖,修改pom.xml

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.deppon.demo</groupId>
  <artifactId>test03</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>test03 Maven Webapp</name>
  <url>http://maven.apache.org</url>
  
   <!-- 属性配置 -->
  <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.10</version>
      <scope>test</scope>
    </dependency>
    
    <!-- 添加Hibernate依赖 -->
    <dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-core</artifactId>
		<version>3.6.5.Final</version>
	</dependency>
	
	<!-- 添加Log4J依赖 -->
	<dependency>
		<groupId>log4j</groupId>
		<artifactId>log4j</artifactId>
		<version>1.2.16</version>
	</dependency>
	
	<dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.6.1</version>
	</dependency>
	
	<dependency>
	    <groupId>org.slf4j</groupId>
	    <artifactId>slf4j-nop</artifactId>
	    <version>1.6.4</version>
	</dependency>
	
	<!-- 添加javassist -->
	<dependency>
		<groupId>javassist</groupId>
		<artifactId>javassist</artifactId>
		<version>3.11.0.GA</version>
	</dependency>
	
  </dependencies>
  
  <build>
    <finalName>test03</finalName>
  </build>
  
</project>

在保存的时候,Maven会自动从库中各种包下载到本地,如果有异常的话,可以尝试手动下载

3. 添加hibernate.cfg.xml和log4j.properties资源文件

注意,资源文件的话,根据约定,需要放在src/main/resources文件夹下

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
		<property name="connection.url">jdbc:sqlserver://localhost:1433;DatabaseName=Demo</property>
		<property name="connection.username">ygy</property>
		<property name="connection.password">shishi</property>
		<property name="javax.persistence.validation.mode">none</property> 

        <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
        
        <property name="current_session_context_class">thread</property>

        <property name="show_sql">true</property>
        <property name="format_sql">true</property>

        <property name="hbm2ddl.auto">update</property>

		<mapping class="com.deppon.test03.entity.PersonEntity"/>
    </session-factory>
</hibernate-configuration>

log4j.properties

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

log4j.rootLogger=debug, stdout

log4j.logger.org.hibernate.tool.hbm2ddl=debug

4. 新建一个实体类,测试一下

PersonEntity.java

package com.deppon.test03.entity;

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

@Entity
@Table(name = "t_person")
public class PersonEntity implements java.io.Serializable {
	private static final long serialVersionUID = -4376187124011546736L;

	private Integer id;
	private String name;

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

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

	@Column(length = 50 , nullable = false , unique = true)
	public String getName() {
		return name;
	}

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

	@Override
	public String toString() {
		return "PersonEntity [id=" + id + ", name=" + name + "]";
	}
	
}

HibernateUtil.java

package com.deppon.test03.util;

import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
	/**ThreadLocal Session Map */
	public static final ThreadLocal<Session> SESSIONMAP = new ThreadLocal<Session>();
	private static final SessionFactory sessionFactory;
	private static final Logger LOGGER = Logger.getLogger(HibernateUtil.class);

	static {
		try {
			LOGGER.debug("HibernateUti.static - loading cofig");
			sessionFactory = new Configuration().configure("hibernate.cfg.xml")
					.buildSessionFactory();
			LOGGER.debug("HibernateUtil.static - end");
		} catch (Throwable ex) {
			ex.printStackTrace();
			LOGGER.error("HibernateUti error : ExceptionInInitializerError");
			throw new ExceptionInInitializerError(ex);
		}
	}
	
	private HibernateUtil() {
		
	}

	public static Session getSession() throws HibernateException {
		Session session = SESSIONMAP.get();
		
		if(session == null) {
			session = sessionFactory.openSession();
			SESSIONMAP.set(session);
		}
		
		return session;
	}
	
	public static void closeSession() throws HibernateException {
		Session session = SESSIONMAP.get();
		SESSIONMAP.set(null);
		
		if(session != null) {
			session.close();
		}
	}

}

测试类 ModelTest.java

package com.deppon.test03.model;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Assert;
import org.junit.Test;

import com.deppon.test03.entity.PersonEntity;
import com.deppon.test03.util.HibernateUtil;

public class ModelTest {
	
	@Test
	public void testGetSession() {
		Session session = HibernateUtil.getSession();
		
		Assert.assertNotNull(session);
		
		HibernateUtil.closeSession();
	}
	
	@Test
	public void testExport() {
		new SchemaExport(new Configuration().configure()).create(true , true);
	}
	
	@Test
	public void testSave() {
		PersonEntity person = new PersonEntity();
		person.setId(100);
		person.setName("路飞");
		
		Session session = HibernateUtil.getSession();
		Transaction tx = session.beginTransaction();
		
		session.save(person);
		
		tx.commit();
		HibernateUtil.closeSession();
	}
	
	@Test
	public void testQuery() {
		Session session = HibernateUtil.getSession();
		session.beginTransaction();
		
		@SuppressWarnings("unchecked")
		List<PersonEntity> personList = session.createQuery("select p from PersonEntity p").list();
		
		for(PersonEntity eachPerson : personList) {
			System.out.println(eachPerson);
		}
		
		session.getTransaction().commit();
		HibernateUtil.closeSession();
	}
	
}

项目结构如下图所示:

对了,注意一下,在上面的pom.xml中,没有看到数据库驱动包,我用的是SQL Server,直接将jar包放到了项目的lib文件夹下,而从网上查的说,使用scope引入本地的包,试了一下,好像不行,等我再试一试。

5. 测试

如果你现在运行JUnit测试的话,是不会成功的,昨天晚上就是这个原因,提示说找不到hibernate.cfg.xml,

后来发现,在target文件夹下,并没有生成class文件,配置文件也没有,这样当然运行不成功

这里需要执行两个命令

使用CMD窗口,进入当前项目的根目录:

第一条命令:输入mvn compile

注意:这里一定要成功啊,即   BUILD SUCCESS

第二条命令:输入mvn test-compile

同样的,这里一定要 BUILD SUCCESS

这样的话,再一次运行测试程序,就可以成功了!大笑


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