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。