使用jfinal写了个web。在windows平台下 ，启动tomcat可以正常访问。部署到linux就报以下错误。

Tomcat版本是一样的

严重: 启动过滤器异常
java.lang.NullPointerException
    at java.util.Hashtable.put(Hashtable.java:394)
    at java.util.Properties.setProperty(Properties.java:143)
    at com.ait.config.JFConfig.configConstant(JFConfig.java:65)
    at com.jfinal.core.Config.configJFinal(Config.java:50)
    at com.jfinal.core.JFinal.init(JFinal.java:63)
    at com.jfinal.core.JFinalFilter.init(JFinalFilter.java:49)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:285)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:266)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:5037)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5739)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1016)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:992)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:639)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1296)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2038)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:662)