SSM项目，一直部署失败，连主页面都无法打开。
在网上找了几个方法尝试都无法奏效，例如直接往WEB-INF添加jar包，更改Tomcat的conf目录下的 catalina.properties 文件。最后发现是配置文件出错，在配置 web.xml 里 context-param 的 param-value 时多写了一个 * 号。
由于是直接复制的千峰李卫民老师博客里的配置文件代码，没想过会在这里出错，前前后后找了两天。
控制台日志如下:
四月 26, 2021 7:13:52 下午 org.apache.catalina.core.StandardContext listenerStart 严重: 异常将上下文初始化事件发送到类的侦听器实例.[org.springframework.web.context.ContextLoaderListener] org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in file [D: 01 LearngingJavaJava单体应用代码my-shop-back argetmy-shop-1.0.0-SNAPSHOTWEB-INFclassescomjluzhmyshopserviceimplUserServiceImpl.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.jluzh.my.shop.service.impl.UserServiceImpl]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1163) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1107) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4701) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5167) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705) at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1720) 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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:287) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:479) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:428) 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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:287) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468) at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76) at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) at java.security.AccessController.doPrivileged(Native Method) at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408) at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) 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 sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357) at sun.rmi.transport.Transport$1.run(Transport.java:200) at sun.rmi.transport.Transport$1.run(Transport.java:197) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:196) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687) 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: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.jluzh.my.shop.service.impl.UserServiceImpl]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:154) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1155) ... 60 more Caused by: java.lang.NullPointerException at com.jluzh.my.shop.commons.context.SpringContext.getBean(SpringContext.java:26) at com.jluzh.my.shop.service.impl.UserServiceImpl.<init>(UserServiceImpl.java:12) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142) ... 62 more 26-Apr-2021 19:13:52.803 严重 [RMI TCP Connection(5)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal 一个或多个listeners启动失败，更多详细信息查看对应的容器日志文件 26-Apr-2021 19:13:52.805 严重 [RMI TCP Connection(5)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal 由于之前的错误，Context[/my_shop_war_exploded]启动失败 四月 26, 2021 7:13:52 下午 org.apache.catalina.core.ApplicationContext log 信息: Closing Spring root WebApplicationContext [2021-04-26 07:13:52,822] Artifact my-shop:war exploded: Error during artifact deployment. See server log for details. 26-Apr-2021 19:14:00.851 信息 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory 把web 应用程序部署到目录 [D:Program Filesapache-tomcat-8.5.54webappsmanager] 26-Apr-2021 19:14:00.933 信息 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [D:Program Filesapache-tomcat-8.5.54webappsmanager] has finished in [81] ms
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <display-name>my-shop</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-context*.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>LoginController</servlet-name> <servlet-class>com.lusifer.my.shop.web.controller.LoginController</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginController</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping> </web-app>