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Tomcat在netbeans中部署相同的应用程序两次

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我正在使用NetBeansTomcat似乎在.war应用程序中部署了两次,这是Web应用程序的双重启动 .

我已经尝试了Tomcat 6和7以及相同的结果 .

我有一个Spring MVC,Hibernate和Thymeleaf应用程序 . META-INF下的Context.xml具有以下内容:

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/website"/>

这是日志 .

**First deployment starts**

[ INFO] 07:13:09 ContextLoader - Root WebApplicationContext: initialization started
[ INFO] 07:13:09 XmlWebApplicationContext - Refreshing Root WebApplicationContext:     startup date [Thu May 23 07:13:09 EST 2013]; root of context hierarchy
2013-05-23 07:13:10 JRebel: Monitoring Spring bean definitions in     '/Users/pack/NetBeansProjects/mysite/site/src/main/webapp/WEB-INF/applicationContext-  data.xml'.
[ INFO] 07:13:10 XmlBeanDefinitionReader - Loading XML bean definitions from     ServletContext resource [/WEB-INF/applicationContext-data.xml]
[ INFO] 07:13:10 ClassPathScanningCandidateComponentProvider - JSR-330 'javax.inject.Named' annotation found and supported for component scanning
            ***(tomcat initializes hibernate and other spring beans)***
                                      ...
May 23, 2013 7:13:17 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 15552 ms
                                 ***Tomcat started***
                      ***Tomcat tries to shut down the context***

[ INFO] 07:13:18 XmlWebApplicationContext - Closing WebApplicationContext for namespace     'spring-mvc-servlet': startup date [Thu May 23 07:13:15 EST 2013]; parent: Root WebApplicationContext
[ INFO] 07:13:18 DefaultListableBeanFactory - Destroying singletons in  org.springframework.beans.factory.support.DefaultListableBeanFactory@5bbe2de2: defining beans    [blHeadProcessor,blHeadProcessorExtensionManager,navigationProcessor,blPaginationPageLinkPro cessor,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,blRegisterCustomerValidator,blCategoryController,com.package.ui.thymeleaf.CategoryHandlerMapping#0,templateResolver,templateEngine,org.thymeleaf.spring3.view.ThymeleafViewResolver#0,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; parent:   org.springframework.beans.factory.support.DefaultListableBeanFactory@521e7f21
[ INFO] 07:13:18 XmlWebApplicationContext - Closing Root WebApplicationContext: startup  date [Thu May 23 07:13:09 EST 2013]; root of context hierarchy 
[ INFO] 07:13:18 DefaultListableBeanFactory - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@521e7f21: defining beans    [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,org.springframework.context.support.PropertySourcesPlaceholderConfigurer#0,blCategoryDao,blCustomerDao,blIdGenerationDao,nlpDao,jpaTemplate,webDS,entityManagerFactory,transactionManager,org.springframework.security.filterChains,org.springframework.security.filterChainProxy,org.springframework.security.web.DefaultSecurityFilterChain#0,org.springframework.security.web.DefaultSecurityFilterChain#1,org.springframework.security.web.DefaultSecurityFilterChain#2,org.springframework.security.web.DefaultSecurityFilterChain#3,org.springframework.security.web.DefaultSecurityFilterChain#4,org.springframework.security.web.DefaultSecurityFilterChain#5,org.springframework.security.web.PortMapperImpl#0,org.springframework.security.web.PortResolverImpl#0,org.springframework.security.authentication.ProviderManager#0,org.springframework.security.web.context.HttpSessionSecurityContextRepository#0,org.springframework.security.web.savedrequest.HttpSessionRequestCache#0,org.springframework.security.web.access.channel.ChannelDecisionManagerImpl#0,org.springframework.security.access.vote.AffirmativeBased#0,org.springframework.security.web.access.intercept.FilterSecurityInterceptor#0,org.springframework.security.web.access.DefaultWebInvocationPrivilegeEvaluator#0,org.springframework.security.authentication.AnonymousAuthenticationProvider#0,org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter#0,org.springframework.security.userDetailsServiceFactory,org.springframework.security.web.DefaultSecurityFilterChain#6,org.springframework.security.authentication.dao.DaoAuthenticationProvider#0,org.springframework.security.authentication.DefaultAuthenticationEventPublisher#0,org.springframework.security.authenticationManager,blUserDetailsService,blCatalogService,blCustomerService,entityService,fbPageService,blIdGenerationService,blLoginService,nlpService,priceIncreaseValidator,searchFacetService,blEntityConfiguration,blPasswordEncoder,solrIndexService,solrEmbedded,textEncryptor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy
[ INFO] 07:13:18 LocalContainerEntityManagerFactoryBean - Closing JPA EntityManagerFactory for persistence unit 'blPU'
[ INFO] 07:13:18 SessionFactoryImpl - closing
May 23, 2013 7:13:18 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/website] registered the JDBC driver    [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To   prevent a memory leak, the JDBC Driver has been forcibly unregistered.
May 23, 2013 7:13:19 AM org.apache.catalina.startup.HostConfig deleteRedeployResources
INFO: Undeploying context [/website]
May 23, 2013 7:13:19 AM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor /Users/pack/Servers/apache-tomcat- 7.0.34/conf/Catalina/localhost/website.xml
2013-05-23 07:13:23 JRebel: Monitoring Log4j configuration in   'file:/Users/pack/NetBeansProjects/mysite/site/target/mycompany/WEB-INF/classes/log4j.xml'.

                          ***Tomcat tries to restart again***

[ INFO] 07:13:23 ContextLoader - Root WebApplicationContext: initialization started
[ INFO] 07:13:23 XmlWebApplicationContext - Refreshing Root WebApplicationContext:   startup date [Thu May 23 07:13:23 EST 2013]; root of context hierarchy
2013-05-23 07:13:24 JRebel: Monitoring Spring bean definitions in   '/Users/pack/NetBeansProjects/mysite/site/src/main/webapp/WEB-INF/applicationContext-  data.xml'.
[ INFO] 07:13:24 XmlBeanDefinitionReader - Loading XML bean definitions from ServletContext resource [/WEB-INF/applicationContext-data.xml]

它成功启动 .

我不明白的是Tomcat为什么要两次部署应用程序 . 第一次在新的tomcat实例上部署应用程序时不会发生这种情况,因为website.xml文件尚未位于tomcats / conf / catalina / localhost文件夹中 . 但是当我再次从netbeans停止并运行tomcat时,website.xml文件仍然在/ conf / catalina / localhost文件夹中,但在第二次部署即将发生之前就被删除并重新部署 .

我已经尝试将Tomcat的server.xml文件中的 autoDeploy 设置为false但它没有帮助 .

<Host name="localhost"  appBase="webapps"
        unpackWARs="true" autoDeploy="false">

可能是每次tomcat停止时,Tomcat应该删除/ conf / catalina / localhost文件夹下的website.xml文件 .

这就是localhost文件夹下的website.xml文件的样子

<?xml version="1.0" encoding="UTF-8"?>
<Context
    docBase="/Users/pack/NetBeansProjects/mysite/site/target/mycompany"  
    path="/website"
/>

3 回答

  • 3

    我发现删除文件conf / localhost / myappname.xml会阻止应用程序初始化两次 . 基本上Tomcat正在重新启动,并重新启动旧版本的应用程序 . 然后当Netbeans部署它时它再次启动 . 作为一种解决方法,我在ContextListener contextDestroyed()事件中添加了几行代码:

    public void contextDestroyed(ServletContextEvent sce) {
    ...
    String delme = sce.getServletContext().getInitParameter("eraseOnExit");
    if (delme != null && delme.length() > 0) {
        File del = new File(delme);
        if (del.exists()) {
            System.out.println("Deleting file " + delme);
            del.delete();
        }
    }
    

    在web.xml中,在开发环境中添加以下内容:

    <context-param>
        <description>Workaround for Tomcat starting webapp twice</description>
        <param-name>eraseOnExit</param-name>
        <param-value>/Users/xxx/apache-tomcat-7.0.42/conf/Catalina/localhost/myappname.xml</param-value>
    </context-param>
    

    然后,下次部署应用程序时,它将不会在部署之前再次启动,因此不会启动两次 . 在部署或关闭之前删除文件的任何其他想法将不胜感激 .

  • 7

    感谢the answer by epochanswer by Steven Neiner .

    这是我的代码版本 . 我的分歧:

    • 标记方法为 synchronized .

    • 理论上不需要,但鉴于我们在这里处理奇怪的多重发射问题,最好是安全而不是抱歉 .

    • 替换了对第三方实用程序的调用(Spring?) .

    • 通过查找 catalina.base 路径中的某些措辞来检测是否在开发中运行 .

    • 删除了 static 修饰符 . 使用作为枚举实现的单例 .

    • 截至2016-05,重写代码以便于阅读和理解(至少对我而言) . 仅进行了简单测试,因此请务必在使用前查看源代码(必须完全使用,风险自负) .

    概念

    他们解决此错误的核心是删除以您的Web应用程序名称命名的文件(您的“servlet上下文”)并附加 .xml .

    例如,如果您的Web应用程序名为 AcmeApp ,请找到并删除名为 AcmeApp.xml 的文件 . 此文件存储在“Catalina base”文件夹中 .

    将此删除作为Web应用程序运行的最后一步 . 因此,当Web应用程序再次启动时,该文件将不存在,并将重新创建 . 请记住,这只是在开发模式下 . 在 生产环境 中单独使用Tomcat时不会发生错误 .

    那么我们如何运行此变通方法代码作为我们的Web应用程序执行的最后一个行为?继续阅读 .

    如何使用

    作为版本2.3及更高版本Servlet spec的标准部分,每个Servlet container都可以在您的网络启动时调用您的代码,并在您的Web应用程序关闭时再次调用 . 这不是Tomcat特有的; JettyGlassFishWildFly/JBoss等等,都包含Servlet规范要求的此功能 .

    要使用上面显示的代码,请在项目中添加一个新类 . 将新类命名为"MyServletContextListener.java" . 将该类声明为实现ServletContextListener接口 .

    实现此接口所需的两种方法 . 当您的Web应用程序启动时,您的Servlet容器(Tomcat)会调用一种方法,保证在第一个用户访问您的应用程序之前运行 . 当您的Web应用程序被Servlet容器(Tomcat)关闭时,将调用另一个方法 .

    contextDestroyed 方法中,调用上面显示的方法 . 像这样:

    @Override
    public void contextInitialized ( ServletContextEvent sce )
    {
        // Web app launching. 
        // This method runs *before* any execution of this web app’s servlets and filters.
        // Do nothing. No code needed here.
    }
    
    @Override
    public void contextDestroyed ( ServletContextEvent sce )
    {
        // Web app shutting down. 
        // This method runs *after* the last execution of this web app’s servlets and filters.
        // Workaround for NetBeans problem with launching Tomcat twice.
        this.workaroundTomcatNetbeansRedeployBug( sce );
    }
    

    配置很简单 . 仅仅将这个类与你的servlet类一起包含在一起WAR file/folder . @WebListener注释使Servlet容器“注意”此侦听器类,加载并实例化它,并在适当时执行其每个方法 . 如果需要,您可以使用备用配置模式而不是注释,但注释是最简单的路径 .

    这是一个整个AppListener类作为完整示例 . 我重写了以前发布的此代码版本,以便于阅读和理解 .

    package com.basilbourque;
    
    import java.io.File;
    import java.io.FilenameFilter;
    import javax.servlet.ServletContextEvent;
    import javax.servlet.ServletContextListener;
    import javax.servlet.annotation.WebListener;
    
    /**
     * Hooks into the web app launching and quitting, as a workaround for Tomcat
     * running from NetBeans causing the web app to rapidly deploy, undeploy and
     * redeploy.
     *
     * © 2016 Basil Bourque. This source code may be used freely, and entirely at
     * your own risk, according to terms of the ISC License at:
     * https://opensource.org/licenses/ISC
     *
     * @author Basil Bourque
     */
    @WebListener
    public class AppListener implements ServletContextListener {
    
        @Override
        public void contextInitialized ( final ServletContextEvent servletContextEventArg ) {
            System.out.println ( "Basil launch" );
        }
    
        @Override
        public void contextDestroyed ( final ServletContextEvent servletContextEventArg ) {
            System.out.println ( "Basil exit" );
            this.workaroundTomcatNetbeansRedeployBug ( servletContextEventArg );
        }
    
       synchronized private void workaroundTomcatNetbeansRedeployBug ( final ServletContextEvent servletContextEventArg ) {
            // When running Tomcat 8 from NetBeans 8, as we do in development, a bug causes the web app to rapidly deploy, undeploy, and redeploy.
            // This bug causes multiple bad side-effects.
            //
            // Workaround: When running in development mode with NetBeans & Tomcat, delete the XML file with name of web app, found in {catalina-base}/conf/Catalina/localhost/YourWebAppNameHere.xml.
            // Example of file name to delete: If your app is named “AcmeApp”, then in a Vaadin multi-module Maven archetype app, the target file might be named “AcmeApp-ui.xml”.
            // In a simpler project, the target file might be named “AcmeApp.xml”.
            // So we need to determine the name of the web app in a soft-coded fashino.
            // We extract from a context path. For example, '/AcmeApp-ui'. We need to remove that slash (SOLIDUS) at the front.
            // Then we append a “.xml” to create our target file name.
            // We look for that file in the folder nested in the Cataline base folder (see line above for path).
            // If file is found, add it to the list of files to be deleted. That list will have only one element.
            // Lastly, delete the file.
            if ( AppUtility.INSTANCE.isInDevelopmentMode () ) {  // Find a strategy to determine if you are in development mode.
                final String catalinaBase = System.getProperty ( "catalina.base" );// Path to the folder the working folder of this web app.
    
                final String contextPath = servletContextEventArg.getServletContext ().getContextPath ();
                final String contextName = contextPath.substring ( 1 ); // Strip the SOLIDUS (slash) from first character position. Example: '/AcmeApp-ui' becomes 'AcmeApp-ui'.
                final String fileNameToDelete = contextName + ".xml";
    
                final File catalinaBaseContext = new File ( catalinaBase , "conf/Catalina/localhost" ); // While in development, running Tomcat from NetBeans, the web app’s name is 'localhost'.
                if ( catalinaBaseContext.exists () && catalinaBaseContext.canRead () ) {  // Confirm that we found the expected configuration folder nested in Catalina’s 'base' folder.
                    // Make an array of File objects that match our criterion of having one of our expected file names.
                    // Populate this array by defining a filter of filenames via a functional interface, to be applied against each file found in folder.
                    final File[] filesToDelete = catalinaBaseContext.listFiles ( new FilenameFilter () {
                        @Override
                        public boolean accept ( File dir , String name ) {
                            boolean accepting = ( name.equals ( fileNameToDelete ) );
                            return accepting;
                        }
                    } );
    
                    if ( filesToDelete.length == 0 ) {  // If list of files is empty…
                        // FIXME Handle error. Should always find one file to delete.
                        System.out.println ( "ERROR - Found no file to delete as workaround for NetBeans+Tomcat double-launch bug. Expected file name: " + fileNameToDelete + " | Message # 42ec5857-9c1b-431a-b5c1-2588669a0ee2." );
                        return;
                    }
    
                    if ( filesToDelete.length > 1 ) {  // If list of files has more than one file…
                        // FIXME Handle error. Should never find more than one file to delete.
                        System.out.println ( "ERROR - Found more than one file to delete as workaround for NetBeans+Tomcat double-launch bug." + " | Message # 0afbd6ca-3722-4739-81dc-b2916e9dbba4." );
                        return;
                    }
    
                    for ( File file : filesToDelete ) {
                        file.delete ();  // Delete first file found in our filtered array.
                        // FIXME You may want to log this deletion.
                        System.out.println ( "TRACE - Deleting file as workaround for NetBeans+Tomcat double-launch bug: " + file + " | Message # 5a78416c-6653-40dc-a98c-6d9b64766d96." );
                        break; // Should be exactly one element in this list. But out of abundant caution, we bail-out of the FOR loop.
                    }
                }
            }
    
        }
    
    }
    

    这里是帮助程序类,用于确定是否在开发模式下运行 . 阅读评论以获得更多讨论 . 结果是在开发时似乎没有简单的干净方法来检测,无法检测何时从NetBeans运行Tomcat而不是自己运行Tomcat . I have asked但尚未收到任何更好的解决方案 .

    CAVEAT: 您必须更改此 isInDevelopmentMode 方法以匹配您的特定开发环境 .

    package com.basilbourque;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * Detects if this web app is running in the Apache Tomcat web container from
     * within NetBeans during development time.
     *
     * © 2016 Basil Bourque. This source code may be used freely, and entirely at
     * your own risk, according to terms of the ISC License at:
     * https://opensource.org/licenses/ISC
     *
     * @author Basil Bourque.
     */
    public enum AppUtility {
    
        INSTANCE;
    
        transient private Boolean isDevMode;
    
        synchronized public Boolean isInDevelopmentMode () {
    
            // There is no simple direct way to detect if running in development.
            // As a workaround, I use some facts specific to my running Tomcat from NetBeans while developing.
            //
            // The “Catalina base” is the folder used by Tomcat’s Catalina module to do the work of your servlets.
            // The names of the folders in the path to that folder can be a clue about running in development.
            //
            // By default, the Catalina base folder is nested within Tomcat’s own folder.
            //
            // If you run NetBeans with a bundled Tomcat installation that path may contain the word “NetBeans”.
            // At least this is the case on Mac OS X where that bundled Tomcat is stored within the NetBeans app (an app is actually a folder in Mac OS X).
            //
            // You mant to create your own folder to hold Tomcat’s “base” folder.
            // I do this on my development machine. I create a folder named something like "apache-tomcat-base-dev" in my home folder.
            // Nested inside that  folder are additional folders for each version of Tomcat I may be using, such as 'base-8.0.33'.
            // Since I do not use such a name on my production environment, I can example the path for that phrasing to indicate development mode.
            //
            if ( null == this.isDevMode ) {  // Lazy-loading.
                // Retrieve the folder path to the current Catalina base folder.
                String catalinaBaseFolderPath = System.getProperty ( "catalina.base" );
    
                this.isDevMode = Boolean.FALSE;
    
                // Examine that path for certain wording I expect to occur only in development and never in production.
                List<String> list = new ArrayList<> ();
                list.add ( "Application Support" );// Specific to Mac OS X only.
                list.add ( "NetBeans" );
                list.add ( "apache-tomcat-base-dev" ); // My own name for an external folder to keep Catalina base separate, outside of NetBeans and Tomcat.
                for ( String s : list ) {
                    if ( catalinaBaseFolderPath.contains ( s ) ) {
                        this.isDevMode = Boolean.TRUE;
                        break;  // Bail-out of the FOR loop after first hit.
                    }
                }
            }
    
            return this.isDevMode;
        }
    
    }
    
  • 2

    首先,谢谢史蒂文!这是一个更便携的修复版本:

    /**
     * tomcat workaround bug, in development mode, if tomcat is stopped and application is not un-deployed,
     * the old application will start up again on startup, and then the new code will be deployed, leading
     * to a the app starting two times and introducing subtle bugs, when this app is stopped and in dev mode
     * remove the deployment descriptor from catalina base
     */
    private static void preventTomcatNetbeansRedeployBug(final ServletContextEvent sce) {
        final String contextPath = sce.getServletContext().getContextPath();
        final String catalinaBase = System.getProperty("catalina.base");
    
        if (StringUtil.checkValidity(contextPath, catalinaBase)
                && FrameworkContext.getInstance().isDevEnvironment()) {
            final File catalinaBaseContext = new File(catalinaBase, "conf/Catalina/localhost");
            if (catalinaBaseContext.exists() && catalinaBaseContext.canRead()) {
                final File[] contexts = catalinaBaseContext.listFiles(new FilenameFilter() {
                    @Override
                    public boolean accept(File dir, String name) {
                        return name.equals(contextPath.substring(1) + ".xml");
                    }
                });
    
                if (contexts != null && contexts.length > 0) {
                    LOG.info("Deleting core context[" + contexts[0].getAbsolutePath() + "] since we are in dev");
                    contexts[0].delete();
                }
            }
        }
    }
    

    PS:用你自己的版本替换未知的引用:)

    ServletContextListener实现的contextDestroyed方法中调用此自定义方法 .

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