0.背景

本来，可以按照《GeoServer速成：安装启动，发布地图，加载QGIS》快速搭建一个GeoServer平台，然后按照文末的方式设置跨域，但是设置完成之后，就会出现这样的错误：

24 十一月 10:55:04 INFO [geoserver.security] - AuthenticationCache Eviction Task created to run every 600 seconds
2021-11-24 10:55:04.556:WARN:oejs.BaseHolder:main:
java.lang.ClassNotFoundException: org.apache.catalina.filters.CorsFilter
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:544)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at org.eclipse.jetty.util.Loader.loadClass(Loader.java:64)
        at org.eclipse.jetty.servlet.BaseHolder.doStart(BaseHolder.java:89)
        at org.eclipse.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.servlet.ServletHandler.lambda$initialize$0(ServletHandler.java:730)
        at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
        at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742)
        at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
        at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:755)
        at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:379)
        at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1457)
        at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1422)
        at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:911)
        at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:288)
        at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:524)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.bindings.StandardStarter.processBinding(StandardStarter.java:46)
        at org.eclipse.jetty.deploy.AppLifeCycle.runBindings(AppLifeCycle.java:188)
        at org.eclipse.jetty.deploy.DeploymentManager.requestAppGoal(DeploymentManager.java:517)
        at org.eclipse.jetty.deploy.DeploymentManager.addApp(DeploymentManager.java:157)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider.fileAdded(ScanningAppProvider.java:173)
        at org.eclipse.jetty.deploy.providers.WebAppProvider.fileAdded(WebAppProvider.java:427)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider$1.fileAdded(ScanningAppProvider.java:66)
        at org.eclipse.jetty.util.Scanner.reportAddition(Scanner.java:785)
        at org.eclipse.jetty.util.Scanner.reportDifferences(Scanner.java:754)
        at org.eclipse.jetty.util.Scanner.scan(Scanner.java:641)
        at org.eclipse.jetty.util.Scanner.doStart(Scanner.java:540)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider.doStart(ScanningAppProvider.java:146)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.DeploymentManager.startAppProvider(DeploymentManager.java:605)
        at org.eclipse.jetty.deploy.DeploymentManager.doStart(DeploymentManager.java:252)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:169)
        at org.eclipse.jetty.server.Server.start(Server.java:423)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:117)
        at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:97)
        at org.eclipse.jetty.server.Server.doStart(Server.java:387)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.xml.XmlConfiguration.lambda$main$3(XmlConfiguration.java:1907)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1857)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.eclipse.jetty.start.Main.invokeMain(Main.java:218)
        at org.eclipse.jetty.start.Main.start(Main.java:491)
        at org.eclipse.jetty.start.Main.main(Main.java:77)
2021-11-24 10:55:04.574:WARN:oejw.WebAppContext:main: Failed startup of context o.e.j.w.WebAppContext@694e1548{GeoServer,/geoserver,file:///D:/Software/GeoServer/webapps/geoserver/,UNAVAILABLE}{D:\Software\GeoServer\webapps\geoserver}
javax.servlet.UnavailableException: Class loading error for holder CorsFilter==org.apache.catalina.filters.CorsFilter@69d145f6{inst=false,async=false,src=DESCRIPTOR:file:///D:/Software/GeoServer/webapps/geoserver/WEB-INF/web.xml}
        at org.eclipse.jetty.servlet.BaseHolder.doStart(BaseHolder.java:96)
        at org.eclipse.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.servlet.ServletHandler.lambda$initialize$0(ServletHandler.java:730)
        at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
        at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742)
        at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
        at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:755)
        at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:379)
        at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1457)
        at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1422)
        at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:911)
        at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:288)
        at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:524)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.bindings.StandardStarter.processBinding(StandardStarter.java:46)
        at org.eclipse.jetty.deploy.AppLifeCycle.runBindings(AppLifeCycle.java:188)
        at org.eclipse.jetty.deploy.DeploymentManager.requestAppGoal(DeploymentManager.java:517)
        at org.eclipse.jetty.deploy.DeploymentManager.addApp(DeploymentManager.java:157)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider.fileAdded(ScanningAppProvider.java:173)
        at org.eclipse.jetty.deploy.providers.WebAppProvider.fileAdded(WebAppProvider.java:427)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider$1.fileAdded(ScanningAppProvider.java:66)
        at org.eclipse.jetty.util.Scanner.reportAddition(Scanner.java:785)
        at org.eclipse.jetty.util.Scanner.reportDifferences(Scanner.java:754)
        at org.eclipse.jetty.util.Scanner.scan(Scanner.java:641)
        at org.eclipse.jetty.util.Scanner.doStart(Scanner.java:540)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.providers.ScanningAppProvider.doStart(ScanningAppProvider.java:146)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.deploy.DeploymentManager.startAppProvider(DeploymentManager.java:605)
        at org.eclipse.jetty.deploy.DeploymentManager.doStart(DeploymentManager.java:252)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:169)
        at org.eclipse.jetty.server.Server.start(Server.java:423)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:117)
        at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:97)
        at org.eclipse.jetty.server.Server.doStart(Server.java:387)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
        at org.eclipse.jetty.xml.XmlConfiguration.lambda$main$3(XmlConfiguration.java:1907)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1857)
        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:498)
        at org.eclipse.jetty.start.Main.invokeMain(Main.java:218)
        at org.eclipse.jetty.start.Main.start(Main.java:491)
        at org.eclipse.jetty.start.Main.main(Main.java:77)

1.检索相关问答

发现在CORS - Tomcat - Geoserver上有一个回答，是使用单独的war包形式部署：

I need to do the same to avoid the usage of a proxy in OpenLayers. Since I'm running Ubuntu 12.04, I've installed Tomcat 7.0.55, instead of the default 7.0.26 (installed from packages). To add CORS headers, I simply added to $CATALINA_HOME/conf/web.xml the following lines:

<filter>
  <filter-name>CorsFilter</filter-name>
  <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
  <init-param>
    <param-name>cors.allowed.origins</param-name>
    <param-value>*</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CorsFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

and then restart tomcat.

2.尝试使用单独的Tomcat解决跨域

2.1.下载war

在官网下载页面，选择Web Archive。

2.2.安装Tomcat

既然回答里安装的是Tomcat 7.0.55，那我们也下载这个版本。打开官方下载地址

Tomcat基础配置，这里就不赘述了，相信经历过SpringMVC的开发人员都会。

2.3.配置web.xml

由于我电脑上只有一个Tomcat，且只是供GeoServer使用，所以CATALINA_HOME我先不设置，直接修改"Tomcat7.0.55\conf\web.xml"。

就按照答案的内容，原封不动在有<filter>的位置的同一层级添加。

<filter>
  <filter-name>CorsFilter</filter-name>
  <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
  <init-param>
    <param-name>cors.allowed.origins</param-name>
    <param-value>*</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CorsFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

我们把下载好war包放入Tomcat7.0.55\webapps

成败在此一举！Tomcat7.0.55\bin\Tomcat7.exe启动，成了，不跨域了。

拓展阅读

• 如何部署WAR到tomcat？