【发布时间】：2010-11-24 13:18:42
【问题描述】：
我正在使用 Struts 2.2.1 和 Hibernate3 编写 Web 应用程序。当我尝试删除与其他实体具有一对多关系的实体时遇到问题。我想实现这样的场景：1）打开会话-> 2）尝试删除实体 3）提交 4）捕获 ConstraintViolationException，然后回滚并向用户显示另一个表中有相关项目的消息。但我无法捕捉到 ConstraintViolationException！这是我的休眠配置：
<?xml version="1.0" encoding="UTF-8"?>
"-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.DerbyDialect</property>
<property name="hibernate.connection.driver_class">org.apache.derby.jdbc.EmbeddedDriver</property>
<property name="hibernate.connection.url">jdbc:derby:c:\soft\db\simple.db;create=true</property>
<property name="hibernate.connection.username">app</property>
<property name="hibernate.connection.password">app</property>
<property name="current_session_context_class">thread</property>
<property name="cache.provider_class">
org.hibernate.cache.NoCacheProvider
</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<property name="hibernate.connection.pool_size">1</property>
<mapping resource="bytes/ewt/model/Shortcuts.hbm.xml"/>
<mapping resource="bytes/ewt/model/Categories.hbm.xml"/>
</session-factory>
</hibernate-configuration>
类别类的映射：
<?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">
<!-- Generated 27 ???? 2010 22:43:18 by Hibernate Tools 3.2.1.GA -->
<hibernate-mapping>
<class catalog="ewt" name="bytes.ewt.model.Categories" table="categories">
<id name="id" type="java.lang.Long">
<column name="ID"/>
<generator class="identity"/>
</id>
<property name="categoryName" type="string">
<column length="200" name="CategoryName" not-null="true" unique="true"/>
</property>
<set inverse="true" name="shortcutses">
<key>
<column name="category_id" not-null="true"/>
</key>
<one-to-many class="bytes.ewt.model.Shortcuts"/>
</set>
</class>
</hibernate-mapping>
我在网络过滤器中的会话管理：
package bytes.ewt.web.filters;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.SessionFactory;
import org.hibernate.StaleObjectStateException;
import bytes.ewt.HibernateUtil;
public class HibernateSessionRequestFilter implements Filter {
private SessionFactory sf;
private static Log log = LogFactory.getLog(HibernateSessionRequestFilter.class);
public void doFilter(ServletRequest request,
ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
try {
if (!sf.getCurrentSession().isOpen())
sf.openSession();
sf.getCurrentSession().beginTransaction();
// Call the next filter (continue request processing)
chain.doFilter(request, response);
// Commit and cleanup
if (sf.getCurrentSession().getTransaction().isActive())
sf.getCurrentSession().getTransaction().commit();
} catch (StaleObjectStateException staleEx) {
log.error("This interceptor does not implement optimistic concurrency control!");
log.error("Your application will not work until you add compensation actions!");
// Rollback, close everything, possibly compensate for any permanent changes
// during the conversation, and finally restart business conversation. Maybe
// give the user of the application a chance to merge some of his work with
// fresh data... what you do here depends on your applications design.
throw staleEx;
} catch (Throwable ex) {
// Rollback only
ex.printStackTrace();
try {
if (sf.getCurrentSession().getTransaction().isActive()) {
//log.debug("Trying to rollback database transaction after exception");
sf.getCurrentSession().getTransaction().rollback();
}
} catch (Throwable rbEx) {
//log.error("Could not rollback transaction after exception!", rbEx);
rbEx.printStackTrace();
}
// Let others handle it... maybe another interceptor for exceptions?
throw new ServletException(ex);
}
}
public void init(FilterConfig filterConfig) throws ServletException {
log.debug("Initializing filter...");
log.debug("Obtaining SessionFactory from static HibernateUtil singleton");
sf = HibernateUtil.getSessionFactory();
}
public void destroy() {}
}
当我尝试使用 Struts2 操作 () 删除类别时，我添加了 system.out 用于调试目的：
public String delete() throws Exception{
if (id == null || id.length() == 0){
addActionError(getText("categories.update.id.empty"));
return "operation_done";
}
CategoriesManager mgr = ApplicationSupervisor.getInstance().getCategoriesManager();
try{
mgr.remove(Long.parseLong(id));
mgr.commit();
} catch(ConstraintViolationException ex){
System.out.println("##Action-catch");
//addActionError(getText("categories.in.use"));
return "operation_done";
} catch(Exception ex){
System.out.println("##Action-all-catch: "+ex.getMessage() + ex.getClass() );
}
return "operation_done";
}
以及mgr的提交代码：
public void commit() throws Exception {
try{
System.out.println("##Pre-commit");
getSession().getTransaction().commit();
System.out.println("##After-commit");
}
catch(Exception ex){
/*getSession().getTransaction().rollback();
HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
*
*/
System.out.println("##Catch-restart");
restartTransaction();
System.out.println("##Restarted-return");
throw ex;
}
}
public void restartTransaction(){
getSession().getTransaction().rollback();
HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
}
所以，当我调用 commit 时，commit 方法中的 catch(Exception ) 应该拦截异常，进行回滚并启动另一个事务，然后再次抛出异常。然后方法 delete 应该捕获 ConstraintViolationException 并添加有关相关实体的操作错误并重定向到索引操作。但不是这个，我得到异常：
SEVERE: DELETE on table 'CATEGORIES' caused a violation of foreign key constraint 'FK8725ACED1BB98B18' for key (1). The statement has been rolled back.
24-Nov-2010 14:56:19 org.hibernate.event.def.AbstractFlushingEventListener performExecutions
SEVERE: Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: could not delete: [bytes.ewt.model.Categories#1]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2541)
at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2697)
at org.hibernate.action.EntityDeleteAction.execute(EntityDeleteAction.java:74)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:234)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:146)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at bytes.ewt.dao.EntitiesDAO.commit(EntitiesDAO.java:34)
at bytes.ewt.struts.CategoriesAction.delete(CategoriesAction.java:120)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:254)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:142)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:166)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:485)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:102)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at ua.org.bytes.ewt.web.filters.HibernateSessionRequestFilter.doFilter(HibernateSessionRequestFilter.java:35)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
##Catch-restart
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
##Restarted-return
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.sql.SQLIntegrityConstraintViolationException: DELETE on table 'CATEGORIES' caused a violation of foreign key constraint 'FK8725ACED1BB98B18' for key (1). The statement has been rolled back.
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown Source)
at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeUpdate(Unknown Source)
at org.hibernate.jdbc.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:23)
at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2520)
... 89 more
Caused by: java.sql.SQLException: DELETE on table 'CATEGORIES' caused a violation of foreign key constraint 'FK8725ACED1BB98B18' for key (1). The statement has been rolled back.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
... 100 more
enter code here
请帮助我理解这种奇怪的行为（在我看来）。
谢谢！
【问题讨论】：