Question

我正在尝试编写一个简单的servlet程序，只需单击HTML页面中的一个按钮，即可获取DB表中的所有详细信息并将其显示为HTML表。

但是，在单击“查看详细信息”按钮时，出现空白页。在验证URL时，可以看到正在访问Servlet，因为它更改为http://localhost:8080/WebApplication2/NewServlet1

我参考了以下教程来学习->（https://www.tutorialspoint.com/servlets/servlets-database-access.htm）

MY HTML CODE

<html>
    <head>
        <title>Employee Deatils</title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
    </head>
    <body>
        <div>
            <form action="NewServlet1" method="post">
                <h1> Press button to view employee details </h1>
                <input type="submit" name="view" value="VIEW DETAILS"/>                
            </form>
        </div>
    </body>
</html>

SERVLET CODE: 

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;

public class NewServlet1 extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            response.setContentType("text/html;charset=UTF-8");

       PrintWriter out = response.getWriter();
       try{
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql:/localhost:3306/test","root","");
        Statement st = conn.createStatement();
        ResultSet rs = st.executeQuery("SELECT * FROM Employees;");

        out.println("<!DOCTYPE html>");
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet NewServlet1</title>");
        out.println("</head>");
        out.println("<body>");
        out.println("<table border = '1' width = '100%'>\n" +
"<tr>\n" +
"<th>Emp ID</th>\n" +
"<th>First Name</th>\n" +
"<th>Last Name</th>\n" +
"<th>Age</th>\n" + 
"</tr>");
        while (rs.next()){
            out.println("<tr>");
            out.println("<td>"+rs.getInt(1)+"</td>" );
            out.println("<td>"+rs.getString(3)+"</td>" );
            out.println("<td>"+rs.getString(4)+"</td>");
            out.println("<td>"+rs.getInt(2)+"</td>");
            out.println("</tr>");
        }
        out.println("</table>");
        out.println("</body>");
        out.println("</html>");

        rs.close();
        st.close();
        conn.close();
       }catch (Exception e){
         e.printStackTrace();       
        }

    }

}

Servlet数据库访问程序返回空白页-Netbeans，Glassfish3

0 个答案: