时间:2021-07-01 10:21:17 帮助过:27人阅读
1.首先,我们把hibernate最基本的数据库连接,使用mysql。 见一个java工程,见一个包名为book, 在book的包下加一个java类Book.java,其代码如下:
package book; public class Book { private Integer id; private String name; private String writer; public Integer get hibernate
最基本的数据库连接,使用mysql。 见一个java工程,见一个包名为“book”
2.然后在在book的包下加一个java类Book.java,其代码如下:
package book; public class Book { private Integer id; private String name; private String writer; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getWriter() { return writer; } public void setWriter(String writer) { this.writer = writer; } }
3.然后在book包下建一个book.hbm.xml,其代码如下:
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="book" default-lazy="false"> <class name="Book"> <id name="id"> <generator class="increment"/> </id> <property name="name" ></property> <property name="writer" ></property> </class> </hibernate-mapping>
4.这个事与数据库里面的字段名形成映射关系,自己在mysql建立book表时与之对应,id是自增长的, 然后在工程的根目录下建一个hibernate.cfg.xml.其代码如下:
<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost/mydb</property> <property name="connection.username">root</property> <property name="connection.password">root</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="show_sql">true</property> <!-- <property name="hbm2ddl.auto">${hibernate.hbm2ddl.auto}</property>--> <!-- <property name="current_session_context_class">thread</property>--> <mapping resource="book/Book.hbm.xml" /> </session-factory> </hibernate-configuration>
5.这是连接mysql数据库的,用户名和密码改为你mysql数据库的
<property name="show_sql">true</property>这是在后台打印sql语句 <mapping resource="book/Book.hbm.xml" />这是找到映射文件。
6.然后些个测试类:代码如下:
package test; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import book.Book; public class MainTest { /** * @param args */ public static void main(String[] args) { try { Configuration cfg=new Configuration()。configure(); SessionFactory sf=cfg.buildSessionFactory(); Session session = sf.openSession(); Transaction ts=session.beginTransaction(); Book b=new Book(); b.setName("hibernate"); b.setWriter("div"); session.save(b); // Book b=(Book) session.get(Book.class,1); // if(b!=null){ // b.setName("xujun"); // System.out.println("书名为:"+b.getName()); // System.out.println("作者为:"+b.getWriter()); // session.delete(b); // } ts.commit(); session.close(); sf.close(); } catch (Exception e) { e.printStackTrace(); } } }
7.mysql表的字段如下:
8.把数据库建好后就可以测试。对了,关键的还没有说,还得把antlr.jar,cglib.jar,asm.jar,asm-attrs.jar,commons-colletions.jar,commons-logging.jar,ehcache.jar, jta.jar,dom4.jar,log4.jar,hibernate3.jar引入到lib目录下
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