Hibernate_HelloWord

Hibernate操作步骤

1.新建项目

2.加jar包

3.写XML配置文件hibernate.cfg.xml

4.写log4j.properties日志文件

5.在MySql数据库中建student表

6.建Student实体类(先建表后建类)

7.写XML映射文件Student.hbm.xml，或者Annotation映射语句

8.在hibernate.cfg.xml中添加相应mapping

9.写测试类main，或者Junit测试类(项目右键-->“New”-->“Junit Test Case”)

HelloWorld小程序----XML映射文件

1.新建项目

2.加jar包。此处列出的jar包是Hibernate所需的全部jar包，在此项目中并不是全部需要

将如下jar包封装进一个User Library，名为hibernate

antlr-2.7.6.jar
c3p0-0.9.1.jar
commons-collections-3.1.jar
dom4j-1.6.1.jar
hibernate3.jar
hibernate-annotations.jar
hibernate-commons-annotations.jar
hibernate-jpa-2.0-api-1.0.0.Final.jar
javassist-3.12.0.GA.jar
jta-1.1.jar
junit-4.10.jar
log4j-1.2.14.jar
mysql-connector-java-5.1.7-bin.jar
slf4j-api-1.6.1.jar
slf4j-log4j12-1.6.1.jar

3.hibernate.cfg.xml配置文件。其中<mapping/>在步骤8中设置

<?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.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost/test</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>

        <!-- JDBC connection pool 连接池 -->
        <!-- <property name="connection.pool_size">1</property> -->

        <!-- SQL dialect 方言-->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- 当前session上下文 . thread:当前线程;jta:(java transaction api) -->
        <property name="current_session_context_class">thread</property> 

        <!-- Disable the second-level cache 去掉二级缓存 -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout 显示sql语句-->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup 常用选项：create和update -->
        <property name="hbm2ddl.auto">update</property>

        <mapping resource="com/hibernate/model/Student.hbm.xml"/>
        <!-- <mapping class="com.hibernate.model.Student"/> -->
        
    </session-factory>
</hibernate-configuration>

4.log4j.properties日志文件

### direct log messages to stdout ###
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

### direct messages to file hibernate.log ###
#log4j.appender.file=org.apache.log4j.FileAppender
#log4j.appender.file.File=hibernate.log
#log4j.appender.file.layout=org.apache.log4j.PatternLayout
#log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change 'info' to 'debug' ###

log4j.rootLogger=warn, stdout

#log4j.logger.org.hibernate=info
#log4j.logger.org.hibernate=debug

### log HQL query parser activity
#log4j.logger.org.hibernate.hql.ast.AST=debug

### log just the SQL
#log4j.logger.org.hibernate.SQL=debug

### log JDBC bind parameters ###
#log4j.logger.org.hibernate.type=info
#log4j.logger.org.hibernate.type=debug

### log schema export/update ###
#log4j.logger.org.hibernate.tool.hbm2ddl=debug

### log HQL parse trees
#log4j.logger.org.hibernate.hql=debug

### log cache activity ###
#log4j.logger.org.hibernate.cache=debug

### log transaction activity
#log4j.logger.org.hibernate.transaction=debug

### log JDBC resource acquisition
#log4j.logger.org.hibernate.jdbc=debug

### enable the following line if you want to track down connection ###
### leakages when using DriverManagerConnectionProvider ###
#log4j.logger.org.hibernate.connection.DriverManagerConnectionProvider=trace

5.在数据库中建表

建表可以在数据库中手动建，也可以通过运行程序自动建立。

此处自动建表

6.建Student实体类

public class Student {
	private int id;
	private String name;
	private int age;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}

7.Student.hbm.xml映射文件

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
	<class name="com.hibernate.model.Student" dynamic-update="true">
		<id name="id">
			<generator class="native"></generator>   <!-- generator设置其id自增 -->
		</id>                                        <!-- id指的是相应表的主键 -->
		<property name="name"></property>
		<property name="age"></property>
	</class>

</hibernate-mapping>

8.在hibernate.cfg.xml中添加相应mapping

9.写测试类main

public class StudentTest {
	public static void main(String[] args) {
		Student s = new Student();
		s.setName("s3");
		s.setAge(10);
		
		SessionFactory sf = new Configuration().configure().buildSessionFactory();
		
		Session session = sf.getCurrentSession();
		session.beginTransaction();
		session.save(s);
		session.getTransaction().commit();
		
		sf.close();
	}

}

程序到此结束，运行后，会自动在数据库创建student表，并将对象s存入student表中。

HelloWorld小程序----Annotation映射语句

步骤1-5同上

6,7.建实体类，添加Annotation注解

@Entity   //表示这是一个实体类，和数据库中的某个表是对应的
public class Teacher {
	private int id;
	private String name;
	private int age;
	
	@Id                //主键
	@GeneratedValue    //ID生成策略，默认为AUTO
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}	
}

8.在hibernate.cfg.xml中添加相应mapping，如下

<mapping class="com.hibernate.model.Student"/>

9.写测试类

测试类有很多种方式

a)见上文测试类main

b)创建一个HibernateUtil辅助类 ，然后再建测试类main

public class HibernateUtil {
	private static SessionFactory sf = buildSessionFactory();

	private static SessionFactory buildSessionFactory() {
		return new Configuration().configure().buildSessionFactory();
	}
	public static SessionFactory getSessionFactory() {
		return sf;
	}
}

public class StudentTest {
	public static void main(String[] args) {
		Student s = new Student();
		s.setName("lisi");
		s.setAge(18);
		
		SessionFactory sf = HibernateUtil.getSessionFactory();
		
		Session session = sf.getCurrentSession();
		session.beginTransaction();
		session.save(s);
		session.getTransaction().commit();
		
		sf.close();		
	}
}

c)建Junit测试类

项目右键-->“New”-->“Junit Test Case”，输入类名，然后完善test方法

public class StudentTest_Junit {
	private static SessionFactory sf = null;
	
	@BeforeClass
	public static void beforeClass(){
		sf = new Configuration().configure().buildSessionFactory();
	}
	
	@AfterClass
	public static void afterClass(){
		sf.close();
	}

	@Test
	public void test() {
		Student s = new Student();
		s.setName("wangwu");
		s.setAge(23);
		
		Session session = sf.getCurrentSession();
		session.beginTransaction();
		session.save(s);
		session.getTransaction().commit();
	}
}

程序到此结束，运行后，会自动在数据库创建student表，并将对象s存入student表中。