org.apache.tomcat.util.scan.StandardJarScanner找不到serializer.jar的问题

我将jsp处理xml必须的两个库文件放在了tomcat的lib文件夹下面：

xalan.jar
xercesImpl.jar

启动tomcat时遇到如下警告消息：

Jul 17, 2020 4:48:18 PM org.apache.tomcat.util.scan.StandardJarScanner processURLs
WARNING: Failed to scan [file:/C:/MyApp/apache-tomcat-9.0.29/lib/serializer.jar] from classloader hierarchy
java.io.FileNotFoundException: C:MyAppapache-tomcat-9.0.29libserializer.jar (The system cannot find the file specified)
	at java.util.zip.ZipFile.open(Native Method)
	at java.util.zip.ZipFile.<init>(ZipFile.java:219)
	at java.util.zip.ZipFile.<init>(ZipFile.java:149)
	at java.util.jar.JarFile.<init>(JarFile.java:166)
	at java.util.jar.JarFile.<init>(JarFile.java:130)
	at org.apache.tomcat.util.compat.JreCompat.jarFileNewInstance(JreCompat.java:177)
	at org.apache.tomcat.util.scan.JarFileUrlJar.<init>(JarFileUrlJar.java:65)
	at org.apache.tomcat.util.scan.JarFactory.newInstance(JarFactory.java:49)
	at org.apache.tomcat.util.scan.StandardJarScanner.process(StandardJarScanner.java:374)
	at org.apache.tomcat.util.scan.StandardJarScanner.processURLs(StandardJarScanner.java:309)
	at org.apache.tomcat.util.scan.StandardJarScanner.doScanClassPath(StandardJarScanner.java:266)
	at org.apache.tomcat.util.scan.StandardJarScanner.scan(StandardJarScanner.java:229)
	at org.apache.catalina.startup.ContextConfig.processJarsForWebFragments(ContextConfig.java:1968)
	at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1128)
	at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:774)
	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:301)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5051)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
	at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
	at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)

我在下载xalan.jar的压缩包里找到了StandardJarScanner processURLs寻找的serializer.jar: http://xml.apache.org/xalan-j/index.html

把它复制到tomcat安装文件夹的lib下面，问题解决了。