不重定向Ok Java Servlet_Java_Jsp_Servlets

不重定向Ok Java Servlet

java jsp servlets

不重定向Ok Java Servlet,java,jsp,servlets,Java,Jsp,Servlets,很抱歉，我又很快地用另一个问题来打扰你，但我看不出原因。。。我看了很长一段时间我的代码（我是noob…）。我认为需要查看的文档有displayrecord.jsp、displaydataservlet、editdata.jsp和editRecordservlet。如果有人有时间，请帮助我，当我点击编辑按钮时，它只会显示一个空白页 Index.jsp <%@page contentType="text/html" pageEncoding="UTF-8"%> <!DOCTYPE

很抱歉，我又很快地用另一个问题来打扰你，但我看不出原因。。。我看了很长一段时间我的代码（我是noob…）。我认为需要查看的文档有displayrecord.jsp、displaydataservlet、editdata.jsp和editRecordservlet。如果有人有时间，请帮助我，当我点击编辑按钮时，它只会显示一个空白页

Index.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body>
    <h4>:::::Employees::::</h4>
    <ul>
        <li><a href="insertrecord.jsp">Create New Employee</a></li>
        <li><a href="DisplayData">Display Employees</a></li>
    </ul>
</body>

}

displayrecord.jsp

<%@page import="java.util.List"%>
<%@page import="java.util.Iterator"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <script type="text/javascript">

            function editRecord(id){
                url = "EditRecord";
                window.location.href = "http://localhost:8084/ZaSkillz/"+url+"?id="+id;

            }
        </script>
        <table align = "center" border="2px" width="80%">
            <%Iterator itr;%>
            <%List data = (List) request.getAttribute("EmpData");
            for(itr = data.iterator(); itr.hasNext();){
                %>
                <tr>
                    <% String s = (String) itr.next();%>
                    <td><%= s %></td>
                    <td><%= itr.next() %></td>
                    <td><%= itr.next() %></td>
                    <td><%= itr.next() %></td>
                    <td><input type= "submit" value = "Edit" name="edit" onclick="editRecord(<%=s%>);"></td>
                    <td><input type= "submit" value = "Delete" name="delete" onclick="deleteRecord(<%=s%>);"></td>
                    <%}%>
                </tr>
        </table>
    </body>
</html>

EditRecord Servlet：

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
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 EditRecord extends HttpServlet {

    Connection conn;
    ResultSet res;
    Statement stmt;
    String id,query;
    DatabaseConnection dbconn;

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        try {
             id= request.getParameter("id");
             dbconn = new DatabaseConnection();
             conn = dbconn.setConnection();
             stmt = conn.createStatement();
             query = "SELECT * FROM CONTACT WHERE id= "+ id ;
             res = dbconn.getResult(query, conn);


        }
        catch(Exception e){ out.println(e);}
        finally {
            request.setAttribute("EditData",res);
            RequestDispatcher rd = request.getRequestDispatcher("/editdata.jsp");
            out.close();
        }
    }


    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }


    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }


    @Override
    public String getServletInfo() {
        return "Short description";
    }

}

editdata.jsp：

<%@page import="java.sql.ResultSet"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1> WTF</h1>
        <form action="EditRecord" method="post">
        <table border ="1px" width ="80%">


                <%ResultSet res = (ResultSet) request.getAttribute("EditData");%>
                <%if(res.next()){
                    %>

                    <tr>
                        <td>ID</td>
                        <td><input type="text" name="id" value=<%=res.getString("id")%> /></td>
                    </tr>

                    <tr>
                        <td>Ename</td>
                        <td><input type="text" name="ename" value=<%=res.getString("ename")%> /></td>
                    </tr>

                    <tr>
                        <td>Designation</td>
                        <td><input type="text" name="desg" value=<%=res.getString("desg")%> /></td>
                    </tr>

                    <tr>
                        <td>Salary</td>
                        <td><input type="text" name="sal" value=<%=res.getString("sal")%> /></td>
                    </tr>
                    <tr>
                        <td></td>
                        <td><input type="submit" value="Update" name="update"></td>
                    </tr>



            <%}%>
        </table>
        </form>
    </body>
</html>


JSP页面
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薪水

web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <servlet>
        <servlet-name>InsertData</servlet-name>
        <servlet-class>InsertData</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>DisplayData</servlet-name>
        <servlet-class>DisplayData</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>EditRecord</servlet-name>
        <servlet-class>EditRecord</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>InsertData</servlet-name>
        <url-pattern>/InsertData</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>DisplayData</servlet-name>
        <url-pattern>/DisplayData</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>EditRecord</servlet-name>
        <url-pattern>/EditRecord</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>


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30

您是否在EditRecord processRequest中设置了断点。密码打到那里了吗？你有例外吗？在哪里进行url映射？断点在哪里？代码写在上面，我错过了什么吗？。是的，代码命中。我没有得到任何例外，这将是一件好事，我只是得到一个空白页：我猜你忘了在你的编辑servlet上做rd.forward（请求，响应）…我的上帝。。。是的，你是对的。现在我得到了java.lang.NullPointerException，我们正在取得进展！尝试在servlet中获取数据，不要像在DisplayData servlet中那样将resultset传递给jsp。

<%@page import="java.sql.ResultSet"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1> WTF</h1>
        <form action="EditRecord" method="post">
        <table border ="1px" width ="80%">


                <%ResultSet res = (ResultSet) request.getAttribute("EditData");%>
                <%if(res.next()){
                    %>

                    <tr>
                        <td>ID</td>
                        <td><input type="text" name="id" value=<%=res.getString("id")%> /></td>
                    </tr>

                    <tr>
                        <td>Ename</td>
                        <td><input type="text" name="ename" value=<%=res.getString("ename")%> /></td>
                    </tr>

                    <tr>
                        <td>Designation</td>
                        <td><input type="text" name="desg" value=<%=res.getString("desg")%> /></td>
                    </tr>

                    <tr>
                        <td>Salary</td>
                        <td><input type="text" name="sal" value=<%=res.getString("sal")%> /></td>
                    </tr>
                    <tr>
                        <td></td>
                        <td><input type="submit" value="Update" name="update"></td>
                    </tr>



            <%}%>
        </table>
        </form>
    </body>
</html>

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <servlet>
        <servlet-name>InsertData</servlet-name>
        <servlet-class>InsertData</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>DisplayData</servlet-name>
        <servlet-class>DisplayData</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>EditRecord</servlet-name>
        <servlet-class>EditRecord</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>InsertData</servlet-name>
        <url-pattern>/InsertData</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>DisplayData</servlet-name>
        <url-pattern>/DisplayData</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>EditRecord</servlet-name>
        <url-pattern>/EditRecord</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>