连接tomcat时出错，HTTP Status 500 -

Question

java.lang.NullPointerException

org.apache.catalina.loader.WebappClassLoaderBase.binaryNameToPath(WebappClassLoaderBase.java:2562)
org.apache.catalina.loader.WebappClassLoaderBase.findLoadedClass0(WebappClassLoaderBase.java:2730)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1208)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1166)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2508)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2497)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:748)

note The full stack trace of the root cause is available in the Apache Tomcat/8.0.36 logs.

Answer 1

明显是代码报错了，空指针，你一定是调用了null的属性或方法，所以就报这种错误了，多学学基础吧，http 500就是代码错误，