我正在尝试使用 MySQL 学习使用 Hibernate，但在一系列错误之前和之后我从未使用过它，我终于被困住了：
Exception in thread "main" org.hibernate.hql.internal.ast.QuerySyntaxException: country is not mapped [from country]
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3291)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3180)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:248)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:183)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:105)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:221)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:199)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1735)
at org.hibernate.tutorial.hbm.Test.main(Test.java:37)
我已经尝试过其他问题的可能解决方案，但没有，它不起作用。这是我到目前为止所做的：
hibernate.cfg.xml（文件夹源代码）
<?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>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/stock</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">create</property>
<!-- configuration pool via c3p0-->
<property name="c3p0.acquire_increment">1</property>
<property name="c3p0.idle_test_period">3600</property> <!-- seconds -->
<property name="c3p0.min_size">3</property>
<property name="c3p0.max_size">5</property>
<property name="c3p0.max_statements">0</property>
<property name="c3p0.timeout">3605</property> <!-- seconds -->
<property name="hibernate.c3p0.preferredTestQuery">select 1;</property>
<!-- Mapping files -->
<!--<mapping resource="country.hbm.xml"/> -->
</session-factory>
</hibernate-configuration>
country.hbm.xml (文件夹 * src\main\resources\org\hibernate\tutorial\hbm* )
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
<class name="org.hibernate.tutorial.hbm.country" table="country">
<id name="id_country">
<property name="country"/>
</class>
</hibernate-mapping>
国家.java
package org.hibernate.tutorial.hbm;
public class country {
private int id_country;
private String country;
public int getId_country() {
return id_country;
}
public void setId_country(int id_country) {
this.id_country = id_country;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
}
测试.java
package org.hibernate.tutorial.hbm;
import java.util.List;
import org.hibernate.SessionFactory;
import org.hibernate.Session;
//import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.tutorial.hbm.country; /* required for test function only */
public class Test {
private static final SessionFactory sessionFactory;
static {
try {
// Initialize factory using contents of hibernate.cfg.xml
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static void main (String[] args) {
country mycls = new country();
/* the id field will auto-increment to a unique value which will distinguish records */
//mycls.setCountry("My Property");
Session session = sessionFactory.openSession();
session.beginTransaction();
List result = session.createQuery( "from country" ).list();
for ( country ctry : (List<country>) result ) {
System.out.println( "Country (" + ctry.getId_country() + ") : " + ctry.getCountry() );
}
session.getTransaction().commit();
session.close(); /* if this test succeeds, you'll find a new record in your MySQL database */
}
}
-编辑 20130301
我已经根据你的建议改变了几件事
休眠.cfg.xml
<!-- Mapping files -->
<mapping resource="org/hibernate/tutorial/hbm/Country.hbm.xml"/>
我重命名并移动了文件 Country.hbm.xml（它是 country.hbm.xml）并更改了它
<class name="Country" table="country">
<!-- <class name="org.hibernate.tutorial.hbm.country" table="country"> -->
该文件已移至src\org\hibernate\tutorial\hbm
country.java 类重命名为 Country.java
最后在 Test.java 中修改了这一行
List result = session.createQuery( "from Country" ).list();
for ( Country ctry : (List<Country>) result ) {
System.out.println( "Country (" + ctry.getId_country() + ") : " + ctry.getCountry() );
}
现在我把它当作一个错误
Initial SessionFactory creation failed.org.hibernate.InvalidMappingException: Could not parse mapping document from resource org/hibernate/tutorial/hbm/Country.hbm.xml
Exception in thread "main" java.lang.ExceptionInInitializerError
at org.hibernate.tutorial.hbm.Test.<clinit>(Test.java:21)
Caused by: org.hibernate.InvalidMappingException: Could not parse mapping document from resource org/hibernate/tutorial/hbm/Country.hbm.xml
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3423)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXmlQueue(Configuration.java:3412)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3400)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1330)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1730)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1781)
at org.hibernate.tutorial.hbm.Test.<clinit>(Test.java:18)
Caused by: org.hibernate.MappingException: class Country not found while looking for property: id_country
at org.hibernate.internal.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:232)
at org.hibernate.mapping.SimpleValue.setTypeUsingReflection(SimpleValue.java:324)
at org.hibernate.cfg.HbmBinder.bindSimpleId(HbmBinder.java:449)
at org.hibernate.cfg.HbmBinder.bindRootPersistentClassCommonValues(HbmBinder.java:382)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:322)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:173)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3420)
... 6 more
Caused by: java.lang.ClassNotFoundException: Country
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.hibernate.internal.util.ReflectHelper.classForName(ReflectHelper.java:192)
at org.hibernate.internal.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:228)
... 12 more
我感谢您的帮助。谢谢你。