Java 错误状态404:源服务器未找到当前表示_Java_Tomcat_Servlets

Java 错误状态404:源服务器未找到当前表示

java tomcat servlets

Java 错误状态404:源服务器未找到当前表示,java,tomcat,servlets,Java,Tomcat,Servlets,我有一个netbeans项目，其结构如下。当我访问localhost:8080/Project/Song时，出现以下错误： HTTP状态404 描述：源服务器未找到目标资源的当前表示形式您知道问题在哪里以及如何纠正吗项目结构： Project Web Pages META-INF WEB-INF web.xml lib jstl-1

我有一个netbeans项目，其结构如下。当我访问localhost:8080/Project/Song时，出现以下错误：

HTTP状态404

描述：源服务器未找到目标资源的当前表示形式

您知道问题在哪里以及如何纠正吗

项目结构：

 Project
        Web Pages
            META-INF
            WEB-INF
               web.xml
               lib
                  jstl-1.2.jar 
           songs.jsp

        Source Packages
            data
                Song.java

package data;    
import org.apache.jena.base.Sys;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;


@WebServlet(name = "/Song")
public class Song extends HttpServlet {
    /*protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    }*/

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        QueryManager qm = new QueryManager();
        ArrayList<ArrayList<String>> result = qm.getSongs();
        qm.closeConnections();

        request.setAttribute("result", result.get(0));
        request.setAttribute("id", result.get(1));
        RequestDispatcher view=request.getRequestDispatcher("songs.jsp");
        view.forward(request,response);
    }

    public void init(){
        System.out.println("Songs page");
    }
}

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
  <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <html>
      <head>
        <link href="style.css" rel="stylesheet">
        <title>Songs List</title>
      </head>
      <body>

        <div id="songs">

          <c:forEach items="${result}" var="item" varStatus="status">
            <a href="/SongPage?name=${result[status.index].replace(" ","+")}&id=${id[status.index]}"> ${result[status.index]} </a> <br />
          </c:forEach>
        </div>

      </body>
    </html>

<?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_3_1.xsd"
         version="3.1">

  <servlet>
    <servlet-name>Song</servlet-name>
    <servlet-class>Song</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Song</servlet-name>
    <url-pattern>/Song</url-pattern>
  </servlet-mapping>

Song.java:

 Project
        Web Pages
            META-INF
            WEB-INF
               web.xml
               lib
                  jstl-1.2.jar 
           songs.jsp

        Source Packages
            data
                Song.java

package data;    
import org.apache.jena.base.Sys;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;


@WebServlet(name = "/Song")
public class Song extends HttpServlet {
    /*protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    }*/

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        QueryManager qm = new QueryManager();
        ArrayList<ArrayList<String>> result = qm.getSongs();
        qm.closeConnections();

        request.setAttribute("result", result.get(0));
        request.setAttribute("id", result.get(1));
        RequestDispatcher view=request.getRequestDispatcher("songs.jsp");
        view.forward(request,response);
    }

    public void init(){
        System.out.println("Songs page");
    }
}

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
  <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <html>
      <head>
        <link href="style.css" rel="stylesheet">
        <title>Songs List</title>
      </head>
      <body>

        <div id="songs">

          <c:forEach items="${result}" var="item" varStatus="status">
            <a href="/SongPage?name=${result[status.index].replace(" ","+")}&id=${id[status.index]}"> ${result[status.index]} </a> <br />
          </c:forEach>
        </div>

      </body>
    </html>

<?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_3_1.xsd"
         version="3.1">

  <servlet>
    <servlet-name>Song</servlet-name>
    <servlet-class>Song</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Song</servlet-name>
    <url-pattern>/Song</url-pattern>
  </servlet-mapping>

包数据；
导入org.apache.jena.base.Sys；
导入javax.servlet.RequestDispatcher；
导入javax.servlet.ServletException；
导入javax.servlet.annotation.WebServlet；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入java.io.IOException；
导入java.util.ArrayList；
@WebServlet（name=“/Song”）
公共类Song扩展了HttpServlet{
/*受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException{
}*/
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
QueryManager qm=新的QueryManager（）；
ArrayList

web xml:

 Project
        Web Pages
            META-INF
            WEB-INF
               web.xml
               lib
                  jstl-1.2.jar 
           songs.jsp

        Source Packages
            data
                Song.java

package data;    
import org.apache.jena.base.Sys;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;


@WebServlet(name = "/Song")
public class Song extends HttpServlet {
    /*protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    }*/

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        QueryManager qm = new QueryManager();
        ArrayList<ArrayList<String>> result = qm.getSongs();
        qm.closeConnections();

        request.setAttribute("result", result.get(0));
        request.setAttribute("id", result.get(1));
        RequestDispatcher view=request.getRequestDispatcher("songs.jsp");
        view.forward(request,response);
    }

    public void init(){
        System.out.println("Songs page");
    }
}

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
  <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <html>
      <head>
        <link href="style.css" rel="stylesheet">
        <title>Songs List</title>
      </head>
      <body>

        <div id="songs">

          <c:forEach items="${result}" var="item" varStatus="status">
            <a href="/SongPage?name=${result[status.index].replace(" ","+")}&id=${id[status.index]}"> ${result[status.index]} </a> <br />
          </c:forEach>
        </div>

      </body>
    </html>

<?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_3_1.xsd"
         version="3.1">

  <servlet>
    <servlet-name>Song</servlet-name>
    <servlet-class>Song</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Song</servlet-name>
    <url-pattern>/Song</url-pattern>
  </servlet-mapping>


歌曲
歌曲
歌曲
/歌

您正在使用两种servlet映射方法。请使用其中一种。注释方法或web.xml从web.xml文件中删除servlet映射。表示删除下面的部分

<servlet>
    <servlet-name>Song</servlet-name>
    <servlet-class>Song</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Song</servlet-name>
    <url-pattern>/Song</url-pattern>
  </servlet-mapping>

用这个

  @WebServlet(name = "Song", urlPatterns = {"/Song"})

尝试将request.getRequestDispatcher（“songs.jsp”）；更改为request.getRequestDispatcher（“/songs.jsp”）；谢谢，但也不起作用！您需要映射WebServlet和xml吗？尝试删除WebServlet..tomcat的哪个版本？歌曲类名应该是packagename.ClassName版本是8.5。servlet名称中的projectdata/Song显示错误无法启动应用程序上下文路径。谢谢，但问题仍然存在。似乎是404错误。谢谢，它与@WebServlet（name=“Song”，urlPatterns={”/Song“}一起工作。