Question

我是JSP和Servlets的新手。

我有两个JSP页面Index.jsp和Edit.jsp以及一个Controller.java。

的index.jsp

 <html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Index</title>
</head>
<body>
    <Form action="/ch2/servletController/Controller">
    <h1>Hello World!</h1>
    <a href="Edit.jsp"> Click here </a>
    <input type="submit" value="Edit" name="gotoEdit" />

    </Form>
</body>
</html>

edit.jsp文件

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Edit</title>
</head>
<body>
    <form action="Controller">
    <h3>This is a simple HTML page that has a form in it.</h3>
    <h3>If there is a value for the hobby in the query string, then it is used to initialize the hobby element. 

    </h3>
    <p>
    Hobby:    
    <input type="text" name="hobby" value="${param.hobby}" />
    <input type="submit" value="Confirm" name="processButton" />
    </p>
    </form>
</body>
</html>

控制器

package ch2.servletController;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

 public class Controller extends HttpServlet
 {
 protected void doGet (HttpServletRequest request,
  HttpServletResponse response)
 throws ServletException, IOException
 {
     String address;
  if (request.getParameter("processButton") !=null)
  {
 address = "Process.jsp";
 }
 else if (request.getParameter("confirmButton") !=null)
 {
    address = "Confirm.jsp";
 }
 else
 {
  address = "Edit.jsp";
    }
    RequestDispatcher dispatcher = 
    request.getRequestDispatcher(address);
   dispatcher.forward(request, response);
   }}

Web Xml

<servlet>
        <servlet-name>Controller</servlet-name>
        <servlet-class>ch2.servletController.Controller</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Controller</servlet-name>
        <url-pattern>/ch2/servletController/Controller</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

所以问题是当我运行index.jsp页面并单击“编辑”按钮时，它会出错。

！[我收到的错误] [4]

请建议!!

Answer 1

以下是一些建议：

1）由于您在href中引用Edit.jsp，请确保两个jsp都位于同一文件夹下。最好的方法是使href =＆＃34;＆lt;％= request.getContextPath（）％＆gt; /Edit.jsp"

2）同样适用于表格行动，即

action =＆＃34;＆lt;％= request.getContextPath（）％＆gt; / ch2 / servletController / Controller＆＃34;

希望这有助于你的事业。

Answer 2

在Edit.jsp中，表单操作是Controller，它应该与web.xml文件中的servlet的url-pattern相对应。在您的情况下，如果您将Edit.jsp表单操作更改为表单action =＆＃34; / ch2 / servletController / Controller＆＃34;，则jsp代码段将找到Servlet。

路径中的Servlet映射错误

2 个答案: