404错误

只有form.html的情况下，请问老师为什么会出现404错误呢，打印不出表单？ Debug日志里面没有显示哪里错误了。这是为什么咧？

[2020-04-07 04:57:41,253] Artifact from:Web exploded: Waiting for server connection to start artifact deployment...

Connected to the target VM, address: '127.0.0.1:50394', transport: 'socket'

07-Apr-2020 16:57:42.591 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version name:   Apache Tomcat/8.5.53

07-Apr-2020 16:57:42.596 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built:          Mar 11 2020 10:01:39 UTC

07-Apr-2020 16:57:42.596 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version number: 8.5.53.0

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name:               Mac OS X

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version:            10.14.6

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture:          x86_64

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home:             /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version:           1.8.0_121-b13

07-Apr-2020 16:57:42.597 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor:            Oracle Corporation

07-Apr-2020 16:57:42.598 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE:         /Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/tomcat/Tomcat_8_5_532_from

07-Apr-2020 16:57:42.599 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME:         /Users/yafeigeng/Desktop/apache-tomcat-8.5.53

07-Apr-2020 16:57:42.601 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=/Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/tomcat/Tomcat_8_5_532_from/conf/logging.properties

07-Apr-2020 16:57:42.601 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager

07-Apr-2020 16:57:42.601 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:50394,suspend=y,server=n

07-Apr-2020 16:57:42.602 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -javaagent:/Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/captureAgent/debugger-agent.jar

07-Apr-2020 16:57:42.602 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote=

07-Apr-2020 16:57:42.602 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.port=1099

07-Apr-2020 16:57:42.603 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.ssl=false

07-Apr-2020 16:57:42.603 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.password.file=/Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/tomcat/Tomcat_8_5_532_from/jmxremote.password

07-Apr-2020 16:57:42.603 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.access.file=/Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/tomcat/Tomcat_8_5_532_from/jmxremote.access

07-Apr-2020 16:57:42.603 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.rmi.server.hostname=127.0.0.1

07-Apr-2020 16:57:42.603 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djdk.tls.ephemeralDHKeySize=2048

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dorg.apache.catalina.security.SecurityListener.UMASK=0027

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dignore.endorsed.dirs=

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=/Users/yafeigeng/Library/Caches/IntelliJIdea2019.3/tomcat/Tomcat_8_5_532_from

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=/Users/yafeigeng/Desktop/apache-tomcat-8.5.53

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=/Users/yafeigeng/Desktop/apache-tomcat-8.5.53/temp

07-Apr-2020 16:57:42.604 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/Users/yafeigeng/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.]

07-Apr-2020 16:57:42.851 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8082"]

07-Apr-2020 16:57:42.932 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read

07-Apr-2020 16:57:42.946 INFO [main] org.apache.catalina.startup.Catalina.load Initialization processed in 1020 ms

07-Apr-2020 16:57:42.987 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]

07-Apr-2020 16:57:42.988 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.53

07-Apr-2020 16:57:42.997 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8082"]

07-Apr-2020 16:57:43.011 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 65 ms

Connected to server

[2020-04-07 04:57:43,395] Artifact from:Web exploded: Artifact is being deployed, please wait...

07-Apr-2020 16:57:44.476 INFO [RMI TCP Connection(2)-127.0.0.1] org.apache.jasper.servlet.TldScanner.scanJars 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.

[2020-04-07 04:57:44,519] Artifact from:Web exploded: Artifact is deployed successfully

[2020-04-07 04:57:44,519] Artifact from:Web exploded: Deploy took 1,124 milliseconds

07-Apr-2020 16:57:53.006 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [/Users/yafeigeng/Desktop/apache-tomcat-8.5.53/webapps/manager]

07-Apr-2020 16:57:53.067 INFO [localhost-startStop-1] org.apache.jasper.servlet.TldScanner.scanJars 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.

07-Apr-2020 16:57:53.076 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [/Users/yafeigeng/Desktop/apache-tomcat-8.5.53/webapps/manager] has finished in [70] ms