Question

我正在尝试运行一个基本的sprig应用程序，我已经按照每一步，但我的代码似乎无法正常工作。

web.xml是

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>springone</display-name>

  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>

  <servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

</web-app>

调度-servlet.xml中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id = "HandlerMapping" class = "org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>

    <bean name = "/index.jsp" class = "org.Start"></bean>

    <bean id = "viewResolver" class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

</beans>

控制器

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;

public class Start extends AbstractController {

    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest arg0,
            HttpServletResponse arg1) throws Exception {
        ModelAndView andView =  new ModelAndView("index");
        andView.addObject("msg", "Asslam-O-Alekum");
        return andView;
    }

}

的index.jsp

<body>
    <h1>${msg}</h1>
</body>

更新控制台是

SEVERE: Error during ServletContainerInitializer processing
javax.servlet.ServletException: Failed to instantiate WebApplicationInitializer class
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:160)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5517)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:717)
Caused by: java.lang.NoClassDefFoundError: org/springframework/context/ApplicationContext
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:786)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:144)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2957)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1210)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1690)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2402)
    at java.lang.Class.getConstructor0(Class.java:2712)
    at java.lang.Class.newInstance0(Class.java:343)
    at java.lang.Class.newInstance(Class.java:325)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:157)
    ... 9 more
Caused by: java.lang.ClassNotFoundException: org.springframework.context.ApplicationContext
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    ... 22 more

上面的代码没有在${msg}显示任何输出，我该如何调试此错误。有什么建议吗？

Answer 1

这些行

    Caused by: java.lang.ClassNotFoundException: org.springframework.context.ApplicationContext
...
    Caused by: java.lang.NoClassDefFoundError: org/springframework/context/ApplicationContext

告诉你运行时类路径中缺少一个jar。通常，您应用程序所需的所有jar必须位于WEB-INF / lib中，除非它们由Servlet容器（或应用程序服务器）提供，并且可由应用程序层次结构中的某个ClassLoader访问。

在您的情况下，ApplicationContext位于spring-context-<version>.jar。检查是否可以在已部署的webapp的WEB-INF / lib文件夹中找到它。

这段代码出了什么问题，它没有显示任何输出

1 个答案: