java新手,为什么你们都能运行起来,我的运行不起来呢?

[chaleaoch]

当然,大概率是我的问题.

这是log,提示正常启动

但是页面404

请问入口地址是?

[ZHENFENG13]

日志不全，不太好确定问题，这就是个普通的maven工程，你就按照maven项目来启动就好了

[chaleaoch]

@ZHENFENG13

谢谢你的及时反馈.

完整log信息如下.
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building ssm-maven 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> tomcat7-maven-plugin:2.2:run (default-cli) > process-classes @ ssm-maven >>>
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ ssm-maven ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 15 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.2:compile (default-compile) @ ssm-maven ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] <<< tomcat7-maven-plugin:2.2:run (default-cli) < process-classes @ ssm-maven <<<
[INFO]
[INFO] --- tomcat7-maven-plugin:2.2:run (default-cli) @ ssm-maven ---
[INFO] Running war on http://localhost:8888/ssm-maven
[INFO] Using existing Tomcat server configuration at C:\learning\java_proj\ssm-demo\ssm-maven\target\tomcat
[INFO] create webapp with contextPath: /ssm-maven
May 04, 2018 8:41:29 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8888"]
May 04, 2018 8:41:29 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Tomcat
May 04, 2018 8:41:29 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.47
May 04, 2018 8:41:32 AM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
May 04, 2018 8:41:32 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
May 04, 2018 8:41:35 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'springMVC'
May 04, 2018 8:41:36 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8888"]
May 04, 2018 8:41:36 AM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.main_jsp._jspInit(main_jsp.java:31)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:489)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:338)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

May 04, 2018 8:41:36 AM org.apache.catalina.core.StandardHostValve custom
SEVERE: Exception Processing ErrorPage[errorCode=404, location=/main.jsp]
org.apache.jasper.JasperException: java.lang.NullPointerException
at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:585)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:396)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:489)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:338)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at org.apache.jsp.main_jsp._jspInit(main_jsp.java:31)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
... 22 more

IDEA自动安装依赖,双击 tomcat7:run

浏览器 输入http://localhost:8888/ssm-maven/ 回车

java1.8 apache-tomcat-8.5.30 IDEA2018.1

如果需要提供其他信息,请告诉我.

谢谢你的帮助.

[chaleaoch]

你好,我刚刚搭建成功了,

首先mvn compile 然后使用IDEA 手动创建tomcat实例.而不是使用mvn的tomcat插件.

[ZHENFENG13]

ok，记得做个笔记，省得以后不知所措。

[chaleaoch]

@ZHENFENG13
经过最近几天对maven,java web的理解,有一个问题想想你请教,

上面我说能够跑起来,实际上只有通过maven 打包 -- IDEA运行 -- 这样是可以成功的.

但是当我使用maven的tomcat插件,提示404,百思不得其解.

log

C:\Java\jdk1.8.0_162\bin\java -Dmaven.multiModuleProjectDirectory=C:\learning\java_proj\ssm-demo\ssm-maven "-Dmaven.home=C:\Program Files\JetBrains\IntelliJ IDEA 2018.1\plugins\maven\lib\maven3" "-Dclassworlds.conf=C:\Program Files\JetBrains\IntelliJ IDEA 2018.1\plugins\maven\lib\maven3\bin\m2.conf" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2018.1\lib\idea_rt.jar=51100:C:\Program Files\JetBrains\IntelliJ IDEA 2018.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\JetBrains\IntelliJ IDEA 2018.1\plugins\maven\lib\maven3\boot\plexus-classworlds-2.5.2.jar" org.codehaus.classworlds.Launcher -Didea.version=2018.1 -DskipTests=true org.apache.tomcat.maven:tomcat7-maven-plugin:2.2:run -f pom.xml
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building ssm-maven 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> tomcat7-maven-plugin:2.2:run (default-cli) > process-classes @ ssm-maven >>>
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ ssm-maven ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 15 resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.2:compile (default-compile) @ ssm-maven ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] <<< tomcat7-maven-plugin:2.2:run (default-cli) < process-classes @ ssm-maven <<<
[INFO] 
[INFO] --- tomcat7-maven-plugin:2.2:run (default-cli) @ ssm-maven ---
[INFO] Running war on http://localhost:8080/ssm-maven
[INFO] Using existing Tomcat server configuration at C:\learning\java_proj\ssm-demo\ssm-maven\target\tomcat
[INFO] create webapp with contextPath: /ssm-maven
May 09, 2018 3:24:13 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
May 09, 2018 3:24:13 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Tomcat
May 09, 2018 3:24:13 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.47
May 09, 2018 3:24:15 PM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
May 09, 2018 3:24:15 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
May 09, 2018 3:24:17 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'springMVC'
May 09, 2018 3:24:18 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]

[chaleaoch]

[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building ssm-maven 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> tomcat7-maven-plugin:2.2:run (default-cli) > process-classes @ ssm-maven >>>
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ ssm-maven ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 15 resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.2:compile (default-compile) @ ssm-maven ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] <<< tomcat7-maven-plugin:2.2:run (default-cli) < process-classes @ ssm-maven <<<
[INFO] 
[INFO] --- tomcat7-maven-plugin:2.2:run (default-cli) @ ssm-maven ---
[INFO] Running war on http://localhost:8080/ssm-maven
[INFO] Using existing Tomcat server configuration at C:\learning\java_proj\ssm-demo\ssm-maven\target\tomcat
[INFO] create webapp with contextPath: /ssm-maven
May 09, 2018 3:24:13 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
May 09, 2018 3:24:13 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Tomcat
May 09, 2018 3:24:13 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.47
May 09, 2018 3:24:15 PM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
May 09, 2018 3:24:15 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
May 09, 2018 3:24:17 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'springMVC'
May 09, 2018 3:24:18 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
May 09, 2018 3:27:51 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
	at org.apache.jsp.main_jsp._jspInit(main_jsp.java:31)
	at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
	at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:489)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
	at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
	at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:338)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

May 09, 2018 3:27:51 PM org.apache.catalina.core.StandardHostValve custom
SEVERE: Exception Processing ErrorPage[errorCode=404, location=/main.jsp]
org.apache.jasper.JasperException: java.lang.NullPointerException
	at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:585)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:396)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:489)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
	at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
	at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:338)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
	at org.apache.jsp.main_jsp._jspInit(main_jsp.java:31)
	at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
	at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
	... 22 more

[ZHENFENG13]

用mvn tomcat:run-war命令，注意是run-war。

[huowolf]

注意项目的打包方式：packaging>war</packaging>

[chaleaoch]

@ZHENFENG13 @huowolf

谢谢二位的指点.