重拾Hibernate(一)之环境配置

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