如何在Tomcat 9.0.0M10中修复"已扫描但未在其中找到TLD的JAR"

Question

我是Java EE的新手,并尝试使用ServletContextListener,并且侦听器作业是连接到数据库bla bla.当我尝试启动服务器(Tomcat 9)时,它仍然停留在:

"信息:至少有一个JAR被扫描用于尚未包含TLD的TLD.启用此记录器的调试日志记录,以获取已扫描但未找到TLD的完整JAR列表.在扫描期间跳过不需要的JAR可以缩短启动时间和JSP编译时间."

所以我改变了"Logging properties file"中的一些属性,如下所示:

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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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handlers = 1catalina.org.apache.juli.AsyncFileHandler, 2localhost.org.apache.juli.AsyncFileHandler, 3manager.org.apache.juli.AsyncFileHandler, 4host-manager.org.apache.juli.AsyncFileHandler, java.util.logging.ConsoleHandler

.handlers = 1catalina.org.apache.juli.AsyncFileHandler, java.util.logging.ConsoleHandler

############################################################
# Handler specific properties.
# Describes specific configuration info for Handlers.
############################################################

1catalina.org.apache.juli.AsyncFileHandler.level = FINE
1catalina.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
1catalina.org.apache.juli.AsyncFileHandler.prefix = catalina.

2localhost.org.apache.juli.AsyncFileHandler.level = FINE
2localhost.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
2localhost.org.apache.juli.AsyncFileHandler.prefix = localhost.

3manager.org.apache.juli.AsyncFileHandler.level = FINE
3manager.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
3manager.org.apache.juli.AsyncFileHandler.prefix = manager.

4host-manager.org.apache.juli.AsyncFileHandler.level = FINE
4host-manager.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
4host-manager.org.apache.juli.AsyncFileHandler.prefix = host-manager.

java.util.logging.ConsoleHandler.level = FINE
java.util.logging.ConsoleHandler.formatter = org.apache.juli.OneLineFormatter


############################################################
# Facility specific properties.
# Provides extra control for each logger.
############################################################

org.apache.catalina.core.ContainerBase.[Catalina].[localhost].level = FINE
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].handlers = 2localhost.org.apache.juli.AsyncFileHandler

org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].level = FINE
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].handlers = 3manager.org.apache.juli.AsyncFileHandler

org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].level = FINE
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].handlers = 4host-manager.org.apache.juli.AsyncFileHandler

# For example, set the org.apache.catalina.util.LifecycleBase logger to log
# each component that extends LifecycleBase changing state:
#org.apache.catalina.util.LifecycleBase.level = FINE

# To see debug messages in TldLocationsCache, uncomment the following line:
org.apache.jasper.compiler.TldLocationsCache.level = FINE
org.apache.jasper.servlet.TldScanner.level = FINE

# To see debug messages for HTTP/2 handling, uncomment the following line:
#org.apache.coyote.http2.level = FINE

# To see debug messages for WebSocket handling, uncomment the following line:
#org.apache.tomcat.websocket.level = FINE

所有答案均可接受 谢谢大家.

Answer 1

这不是tomcat中的错误或任何问题.Tomcat只是告诉您,有些罐子不包含TLD,您可以将它们添加到扫描仪的跳过列表中以提高启动性能.所以你有两个选择:

1. 您可以放心地忽略该提示.然而,如果它让您烦恼,您可以将该特定记录器设置为更高的日志记录级别,从而防止tomcat记录它.只需添加org.apache.jasper.servlet.TldScanner.level = SEVERE到logging.properties的末尾即可.

2. 启用调试日志记录以使tomcat列出这些jar并将它们添加到跳过列表中.组:

   org.apache.jasper.compiler.TldLocationsCache.level = FINE
   org.apache.jasper.servlet.TldScanner.level = FINE
   

并将打印的jar名称(不带路径)添加到tomcat.util.scan.StandardJarScanFilter.jarsToSkip=...tomcat_dir/conf/catalina.properties中

Answer 2

将记录设置为FINE,FINEST或ALL以查找要排除的所有罐子是不必要的.

这是一个脚本,可以找到所有不包含TLD的jar(更改TOMCAT_HOME变量以匹配您的安装)并在表单上输出一个列表

jar1.jar,\
jar2.jar,\
...

可以粘贴到catalina.properties中(省略最后一个',\'):

#!/bin/sh
TOMCAT_HOME=/opt/tomcat
for i in `find $TOMCAT_HOME -follow -name "*jar"`
do
    jar tvf $i | grep -i tld > /dev/null
    if [ $? -ne 0 ]; then
        echo "$(basename $i),\\"
    fi
done

但是,如果我被正确通知,tomcat 9中有可能通过更改(在catalina.properties中)排除所有jar:

tomcat.util.scan.StandardJarScanFilter.jarsToSkip=\

至

tomcat.util.scan.StandardJarScanFilter.jarsToSkip=*.jar

(在下面的行中注释掉该列表)然后通过更改以下内容来覆盖包含TLD的罐子的决定:

tomcat.util.scan.StandardJarScanFilter.jarsToScan=\
log4j-web*.jar,log4j-taglib*.jar,log4javascript*.jar,slf4j-taglib*.jar

并添加通过修改上面的脚本获得的列表,以列出包含TLD的jar:

#!/bin/sh
TOMCAT_HOME=/opt/tomcat
for i in `find $TOMCAT_HOME -follow -name "*jar"`
do
    jar tvf $i | grep -i tld > /dev/null
    if [ $? -eq 0 ]; then
        echo "$(basename $i),\\"
    fi
done

Answer 3

更改conf\context.xml 文件

<Context>
    <!-- only if you do not use jsp tag -->
    <JarScanner>
        <JarScanFilter defaultPluggabilityScan="false" defaultTldScan="false"/>
    </JarScanner>
</Context>

请参阅：https ://tomcat.apache.org/tomcat-9.0-doc/config/jar-scan-filter.html