尝试运行servlet时出现Servlet异常

Question

尝试运行servlet时出现Servlet异常

Par*_*mar 1 java servlets servletexception classnotfoundexception

我是servlet的新手.我正在低于sevlets例外.

我的web.xml代码.

    <display-name>LoginServlets</display-name>
    <servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>LoginServlet</servlet-class>
    </servlet>


    <servlet-mapping>
        <servlet-name>LoginServlet</servlet-name>
        <url-pattern>/login</url-pattern>
    </servlet-mapping>
    <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>

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调用此servlet的Html表单.

<body>
    <form action="login" method="get">
        <table>
            <tr>
                <td>UserName</td>
                <td><input type="text" name="username" /></td>
            </tr>
            <tr>
                <td>Password</td>
                <td><input type="password" name="password" /></td>
            </tr>
            <tr>
                <td><input type="submit" value="SignIn" /></td>
            </tr>
        </table>
    </form>
</body>

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我得到的例外.

javax.servlet.ServletException: Error instantiating servlet class LoginServlet
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)

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根本原因.

java.lang.ClassNotFoundException: LoginServlet
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)

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最后一天类似的代码工作正常.但我也在使用git SVN我用相同的代码设置了一个创建新项目.但它不起作用.我也下载了一些样品但没有工作.

这是我的LoginServlet类.它位于JavaResources-> src-mypackage中

package com.loginservlets;
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginServlet() {
        super();
        // TODO Auto-generated constructor stub
        System.out.println("LoginServlet");
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        System.out.println("Get");
        response.setContentType("text/html");
        PrintWriter pw = response.getWriter();
        pw.println("HelloWorld");
        out.close();

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        System.out.println("Post");
    }

}

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Answer 1

JB *_*zet 5

你班级的名字是com.loginservlets.LoginServlet.没有LoginServlet.

请注意,在web.xml中声明servlet是多余的,并使用注释声明它.没有理由在web.xml中声明它,因为您可以使用注释执行相同的操作:

@WebServlet("/login")

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