當我嘗試將休眠與檢票口一起使用時出錯

Question

我正在使用有關簡單休眠實現的教程 ，並且一切都可以從控制台正常運行，但是當我嘗試通過在網頁上單擊按鈕並通過wicket使用此示例時，出現錯誤

WicketMessage: Can't instantiate page using constructor public com.mycompany.app.StartPage(org.apache.wicket.PageParameters) and argument 

Root cause:

java.lang.NoSuchMethodError: org.slf4j.helpers.MessageFormatter.format(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/String;
     at org.slf4j.impl.Log4jLoggerAdapter.debug(Log4jLoggerAdapter.java:246)
     at org.hibernate.type.BasicTypeRegistry.register(BasicTypeRegistry.java:147)
     at org.hibernate.type.BasicTypeRegistry.<init>(BasicTypeRegistry.java:50)
     at org.hibernate.type.TypeResolver.<init>(TypeResolver.java:59)
     at org.hibernate.cfg.Configuration.<init>(Configuration.java:250)
     at org.hibernate.cfg.Configuration.<init>(Configuration.java:302)
     at com.mycompany.util.HibernateUtil.buildSessionFactory(HibernateUtil.java:13)
     at com.mycompany.util.HibernateUtil.<clinit>(HibernateUtil.java:8)
     at com.mycompany.app.StartPage$3.<init>(StartPage.java:132)
     at com.mycompany.app.StartPage.<init>(StartPage.java:131)
     at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
     at org.apache.wicket.session.DefaultPageFactory.createPage(DefaultPageFactory.java:188)
     at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:65)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:298)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:320)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:234)
     at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92)
     at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1250)
     at org.apache.wicket.RequestCycle.step(RequestCycle.java:1329)
     at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1436)
     at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
     at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)
     at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:319)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
     at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
     at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
     at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
     at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
     at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
     at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
     at java.lang.Thread.run(Thread.java:680)

Complete stack:

org.apache.wicket.WicketRuntimeException: Can't instantiate page using constructor public com.mycompany.app.StartPage(org.apache.wicket.PageParameters) and argument 
     at org.apache.wicket.session.DefaultPageFactory.createPage(DefaultPageFactory.java:212)
     at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:65)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:298)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:320)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:234)
     at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92)
     at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1250)
     at org.apache.wicket.RequestCycle.step(RequestCycle.java:1329)
     at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1436)
     at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
     at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)

java.lang.reflect.InvocationTargetException
     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
     at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
     at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
     at org.apache.wicket.session.DefaultPageFactory.createPage(DefaultPageFactory.java:188)
     at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:65)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:298)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:320)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:234)
     at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92)
     at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1250)
     at org.apache.wicket.RequestCycle.step(RequestCycle.java:1329)
     at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1436)
     at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
     at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)

java.lang.ExceptionInInitializerError
     at com.mycompany.util.HibernateUtil.buildSessionFactory(HibernateUtil.java:17)
     at com.mycompany.util.HibernateUtil.<clinit>(HibernateUtil.java:8)
     at com.mycompany.app.StartPage$3.<init>(StartPage.java:132)
     at com.mycompany.app.StartPage.<init>(StartPage.java:131)
     at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
     at org.apache.wicket.session.DefaultPageFactory.createPage(DefaultPageFactory.java:188)
     at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:65)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:298)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:320)
     at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:234)
     at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92)
     at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1250)
     at org.apache.wicket.RequestCycle.step(RequestCycle.java:1329)
     at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1436)
     at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
     at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)

這是我的StartPage.html

<html>
<head>
    <title>Start Page</title>
</head>
<body>
    <form wicket:id="form">
        <p>
            <input class="button" type="submit" value="load from DB" />
        </p>
    </form>
</body>
</html>

StartPage.java

Form<?> form = new Form<Void>("form") {
    @Override
    protected void onSubmit() {
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session = sessionFactory.openSession();
    }
};
add(form);

hibernate.cfg.xml

<?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>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/test_db</property>
        <property name="hibernate.connection.username">postgres</property>
        <property name="hibernate.connection.password">pass</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
        <property name="show_sql">true</property>
        <property name="current_session_context_class">thread</property>
        <mapping resource="com/mycompany/app/DBUser.hbm.xml"></mapping>
    </session-factory>
</hibernate-configuration>

當我添加此SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();時發生錯誤SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();

Answer 1

有什么例外？ 我注意到的第一件事是您在每個表單提交請求上創建SessionFactory。 會話工廠僅應在應用初始化時創建一次，並且在每個請求中，您僅應獲取休眠會話。

在您的教程中查看HibernateUtil類。 它為SessionFactory創建單例類。