解决Tomcat7“At least one JAR was scanned for TLDs ye

【Tomcat版本】7.0.42

【问题描述】Tomcat启动后，访问动态页面后提示“At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time”

 

【问题原因猜测】Tomcat7/Servlet3.0 新增特性“可插性支持”实现的原理应该是自动扫描jar，当jar中并不包含相关组件时会打印该信息

 

【问题处理】从提示信息来看，不处理也可以，但对于有洁癖的、追求完美的程序员而言这个是不允许的。具体处理步骤：

 

1.调整Tomcat对应类的log级别

修改${tomcat}/conf/log4j.properties

Java代码  

1. ##解除类org.apache.jasper.compiler.TldLocationsCache的log  
2. org.apache.jasper.compiler.TldLocationsCache.level = FINE  

 

 2.观察Tomcat日志打印信息

步骤1执行完后，重启Tomcat，观察Tomcat日志，会在日志中发现类似如下打印信息：

Java代码  

1. 九月 09, 2013 10:55:37 上午 org.apache.jasper.compiler.TldLocationsCache tldScanJar  
2. 详细: No TLD files were found in [file:/E:/devspace/xxt_login/WEB-INF/lib/json-lib-2.3-jdk15.jar]. Consider adding the JAR to the tomcat.util.scan.DefaultJarScanner.jarsToSkip or org.apache.catalina.startup.TldConfig.jarsToSkip property in CATALINA_BASE/conf/catalina.properties file.  
3. 九月 09, 2013 10:55:37 上午 org.apache.jasper.compiler.TldLocationsCache tldScanJar  
4. 详细: No TLD files were found in [file:/E:/devspace/xxt_login/WEB-INF/lib/poi-3.8.jar]. Consider adding the JAR to the tomcat.util.scan.DefaultJarScanner.jarsToSkip or org.apache.catalina.startup.TldConfig.jarsToSkip property in CATALINA_BASE/conf/catalina.properties file.  

 

 

3.调整${tomcat}/conf/catalina.properties，将提示的jar添加到不扫描清单中

Java代码  

1. tomcat.util.scan.DefaultJarScanner.jarsToSkip=\  
2. bootstrap.jar,commons-daemon.jar,tomcat-juli.jar,\  
3. annotations-api.jar,el-api.jar,jsp-api.jar,servlet-api.jar,\  
4. catalina.jar,catalina-ant.jar,catalina-ha.jar,catalina-tribes.jar,\  
5. jasper.jar,jasper-el.jar,ecj-*.jar,\  
6. tomcat-api.jar,tomcat-util.jar,tomcat-coyote.jar,tomcat-dbcp.jar,\  
7. tomcat-jni.jar,tomcat-spdy.jar,\  
8. tomcat-i18n-en.jar,tomcat-i18n-es.jar,tomcat-i18n-fr.jar,tomcat-i18n-ja.jar,\  
9. tomcat-juli-adapters.jar,catalina-jmx-remote.jar,catalina-ws.jar,\  
10. tomcat-jdbc.jar,\  
11. tools.jar,\  
12. commons-beanutils*.jar,commons-codec*.jar,commons-collections*.jar,\  
13. commons-dbcp*.jar,commons-digester*.jar,commons-fileupload*.jar,\  
14. commons-httpclient*.jar,commons-io*.jar,commons-lang*.jar,commons-logging*.jar,\  
15. commons-math*.jar,commons-pool*.jar,\  
16. jstl.jar,\  
17. geronimo-spec-jaxrpc*.jar,wsdl4j*.jar,\  
18. ant.jar,ant-junit*.jar,aspectj*.jar,jmx.jar,h2*.jar,hibernate*.jar,httpclient*.jar,\  
19. jmx-tools.jar,jta*.jar,log4j*.jar,mail*.jar,slf4j*.jar,\  
20. xercesImpl.jar,xmlParserAPIs.jar,xml-apis.jar,\  
21. junit.jar,junit-*.jar,ant-launcher.jar,\  
22. json-lib-*.jar,poi-*.jar  

 

 

【注意】

1.如果使用eclipse server插件、Sysdeo tomcat插件启动Tomcat，此配合可能无效

2.步骤1调整完后，最好清除下以下两个文件夹${tomcat}/conf/Catalina ${tomcat}/work/Catalina

3.尽量使用*号实现模式匹配，以避免因jar版本升级带来的重复修改代价

 

【参考资料】

Servlet3.0新特性

http://blog.csdn.net/aking21alinjuju/article/details/5583820