在J2SE項(xiàng)目中:

<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">
<persistence-unit name="demo" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.ncs.entity.UserInfo</class>
<properties>
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver"/>
<property name="hibernate.connection.url" value="jdbc:oracle:thin:@127.0.0.1:1522:xe"/>
<property name="hibernate.connection.username" value="system"/>
<property name="hibernate.connection.password" value="151923"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.format_sql" value="true"/>
</properties>
</persistence-unit>
</persistence>

注意:配置參數(shù)hibernate.hbm2ddl.auto 各個(gè)取值的含義

validate? update? create? create-drop

? 這幾個(gè)參數(shù)的作用主要用于：自動(dòng)創(chuàng)建? 更新? 驗(yàn)證數(shù)據(jù)庫表結(jié)構(gòu)

? 如果不是此方面的需求取none

??validate：加載hibernate時(shí)，驗(yàn)證創(chuàng)建數(shù)據(jù)庫表結(jié)構(gòu)

??create：每次加載hibernate，重新創(chuàng)建數(shù)據(jù)庫表結(jié)構(gòu)，這就是導(dǎo)致數(shù)據(jù)庫表結(jié)構(gòu)丟失的原因

? create-drop：加載hibernate時(shí)創(chuàng)建，退出是刪除表結(jié)構(gòu)

??update：加載hibernate自動(dòng)更新數(shù)據(jù)庫結(jié)構(gòu)

常見問題排錯(cuò):

1.

Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named HelloTitan
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:56)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:34)
at Main.main(Main.java:10)

原因：沒有Persistence provider

解決辦法：錯(cuò)誤提示很明顯:No Persistence provider.

? (1)檢查lib:jar丟失,則將需要的lib添加到classpath中，Jboss使用的是hibernate實(shí)現(xiàn)，這些lib在下面的目錄中能找到

jboss-X\common\lib\

? (2)可能provider不對(duì).檢查xml文件里面的provider

2.

Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: HelloTitan] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:677)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:126)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:52)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:34)
at Main.main(Main.java:10)
Caused by: org.hibernate.HibernateException: Could not find datasource
at org.hibernate.connection.DatasourceConnectionProvider.configure(DatasourceConnectionProvider.java:79)
at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:137)
at org.hibernate.ejb.InjectionSettingsFactory.createConnectionProvider(InjectionSettingsFactory.java:29)
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:89)
at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2101)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1325)
at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:867)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:669)
... 4 more
Caused by: javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:645)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:325)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at org.hibernate.connection.DatasourceConnectionProvider.configure(DatasourceConnectionProvider.java:75)
... 11 more

原因：JNDI沒有初始化成功

解決辦法：?在classpath添加 jnid.properties 文件 （以JBoss為例，配置如下）

java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces
java.naming.provider.url=127.0.0.1:1099

3.

程序成功運(yùn)行，但是數(shù)據(jù)沒有寫入數(shù)據(jù)庫

原因：沒有提交數(shù)據(jù)

解決辦法：em.getTransaction().commit();

附錄

Hibernate SQL方言 (hibernate.dialect)

RDBMS方言

DB2	org.hibernate.dialect.DB2Dialect
DB2 AS/400	org.hibernate.dialect.DB2400Dialect
DB2 OS390	org.hibernate.dialect.DB2390Dialect
PostgreSQL	org.hibernate.dialect.PostgreSQLDialect
MySQL	org.hibernate.dialect.MySQLDialect
MySQL with InnoDB	org.hibernate.dialect.MySQLInnoDBDialect
MySQL with MyISAM	org.hibernate.dialect.MySQLMyISAMDialect
Oracle (any version)	org.hibernate.dialect.OracleDialect
Oracle 9i/10g	org.hibernate.dialect.Oracle9Dialect
Sybase	org.hibernate.dialect.SybaseDialect
Sybase Anywhere	org.hibernate.dialect.SybaseAnywhereDialect
Microsoft SQL Server	org.hibernate.dialect.SQLServerDialect
SAP DB	org.hibernate.dialect.SAPDBDialect
Informix	org.hibernate.dialect.InformixDialect
HypersonicSQL	org.hibernate.dialect.HSQLDialect
Ingres	org.hibernate.dialect.IngresDialect
Progress	org.hibernate.dialect.ProgressDialect
Mckoi SQL	org.hibernate.dialect.MckoiDialect
Interbase	org.hibernate.dialect.InterbaseDialect
Pointbase	org.hibernate.dialect.PointbaseDialect
FrontBase	org.hibernate.dialect.FrontbaseDialect
Firebird	org.hibernate.dialect.FirebirdDialect

?

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