重拾Hibernate(1)之环境配置

1、新建Web Project工程

2、导入所需jar包

   


3、Student.java

package com.itmyhome;

import javax.persistence.Entity;
import javax.persistence.Table;

@Entity
@Table(name="T_STUDENT")
public class Student extends BizEntity{
private String name;
private String score;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getScore() {
return score;
}
public void setScore(String score) {
this.score = score;
}

}

Teacher.java

package com.itmyhome;

import javax.persistence.Entity;
import javax.persistence.Table;

@Entity
@Table(name="T_TEACHER")
public class Teacher extends BizEntity{
private String name;
private String title;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}

}

BizEntity.java

package com.itmyhome;

import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import org.hibernate.annotations.GenericGenerator;

public class BizEntity {
private String id;

@Id @GeneratedValue(strategy=GenerationType.AUTO,generator="bizGenerator")
@GenericGenerator(strategy = "uuid", name = "bizGenerator")
public String getId() {
return id;
}

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

}

BizEntity.java是所有实体类的父类，id自动生成策略为uuid

4、hibernate.hbm.xml

<?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>
<property name="dialect">org.hibernate.dialect.OracleDialect</property>
<property name="connection.url">jdbc:oracle:thin:@172.16.1.4:1521:orcl</property>
<property name="connection.username">username</property>
<property name="connection.password">123</property>
<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="current_session_context_class">thred</property>

<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">true</property>

</hibernate-mapping>

5、Test.java测试

package com.itmyhome;

import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

public class Test {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//new SchemaExport(new AnnotationConfiguration().configure()).create(true, true);

Teacher t = new Teacher();
                  t.setName("张三");
  
                  Configuration cfg = new AnnotationConfiguration();
                  SessionFactory factory =cfg.configure().buildSessionFactory();
                  Session session = factory.openSession();
                  session.beginTransaction();
                  session.save(t);
                  session.getTransaction().commit();
}
}

SchemaExport自动生成数据表

 

运行程序：

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

此错误是缺少slf4j-nop.x.jar包   添加一个该包(slf4j-nop-1.5.8.jar)

 

Exception in thread "main" java.lang.IllegalAccessError: tried to access field org.slf4j.impl.StaticLoggerBinder.SINGLETON from class org.slf4j.LoggerFactory

 

此错误是slf4j版本错误。slf4j-api是1.5.2而slf4j-nop是1.5.8

删除slf4j-api.1.5.2添加一个1.5.8的

 

Exception in thread "main" java.lang.NoClassDefFoundError: org/hibernate/annotations/common/reflection/ReflectionManager

此错误是少一个jar包，引入hibernate-commons-annotations.jar

 

Caused by: org.xml.sax.SAXParseException: The content of element type "property" must match "(meta*,(column|formula)*,type?)".
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:236)

此错误是hibernate-cfg.xml配置文件错误(刚开始我是从文档中copy的，而那个是mapping实体类的映射文件)

<?xml version="1.0"?>
<!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="dialect">org.hibernate.dialect.OracleDialect</property>
<property name="connection.url">jdbc:oracle:thin:@172.16.1.4:1521:orcl</property>
<property name="connection.username">username</property>
<property name="connection.password">123</property>
<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="current_session_context_class">thred</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">true</property>
</session-factory>
</hibernate-configuration>

 

Exception in thread "main" org.hibernate.HibernateException: JDBC Driver class not found: oracle.jdbc.driver.OracleDriver

没有引入oracle驱动

 

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.itmyhome.Teacher

没有在hibernate.cfg.xml中加入映射

<mapping class="com.itmyhome.Teacher"/>
<mapping class="com.itmyhome.Student"/>

然后运行：

Exception in thread "main" org.hibernate.AnnotationException: No identifier specified for entity: com.itmyhome.Teacher

在BizEntity类上面加上@MappedSuperclass注解  用在实体的继承过程中的父类上。

 

如果直接再次运行的话 会报错 表或视图不存在

而应用SchemaExport先生成表 

hibernate生成的表语句为：

drop table T_STUDENT cascade constraints

drop table T_TEACHER cascade constraints

create table T_STUDENT (
id varchar2(255) not null,
name varchar2(255),
score varchar2(255),
primary key (id)
)

create table T_TEACHER (
id varchar2(255) not null,
name varchar2(255),
title varchar2(255),
primary key (id)
)

此时再插入一条teacher数据：

Hibernate:
insert
into
T_TEACHER
(name, title, id)
values
(?, ?, ?)

最终所需jar包



结束