在Eclipse中使用servlet和jsp将数据插入数据库

Question

我正在尝试使用servlet和jsp以及MySQL Workbench作为数据库在数据库表中添加或插入值。这些是以下详细信息：

1.> Register.java

package register.com;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletConfig;
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.sql.*;
import javax.servlet.*;
/**
* Servlet implementation class Register
*/
@WebServlet("/register")
public class Register extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
 * @see HttpServlet#HttpServlet()
 */
public Register() {
    super();
    // TODO Auto-generated constructor stub
}

    /**
     * @see Servlet#init(ServletConfig)
     */
    public void init(ServletConfig config) throws ServletException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse  response)
     */
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub


            response.setContentType("text/html");  
            PrintWriter pw = response.getWriter(); 
            //String connectionURL = "jdbc:mysql://127.0.0.1:3306/newData";// newData is the database  
            //Connection connection;  
            Connection conn=null;
            String url="jdbc:mysql://localhost:3306/";
            String dbName="userlogindb";
            String driver="com.mysql.jdbc.Driver";
        //String dbUserName="root";
        //String dbPassword="root";

        try{  
          String Fname = request.getParameter("fname");  
          String Mname = request.getParameter("mname");  
          String Lname = request.getParameter("lname");  
          String Uname = request.getParameter("username");  
          String Emailid = request.getParameter("emailid");  
          String Mobno = request.getParameter("mobno");  
          String Address = request.getParameter("address");  
          String Password1 = request.getParameter("password1");  
          String Password2 = request.getParameter("password2");

          Class.forName(driver).newInstance();  
          conn = DriverManager.getConnection(url+dbName,"root", "root");
          PreparedStatement pst =(PreparedStatement) conn.prepareStatement("insert into 'userlogindb'.'registerutable'(fname,mname,lname,username,emailid,mobno,address,password1,password2) values(?,?,?,?,?,?,?,?,?)");//try2 is the name of the table

          pst.setString(1,Fname);  
          pst.setString(2,Mname);        
          pst.setString(3,Lname);
          pst.setString(4,Uname);
          pst.setString(5,Emailid);
          pst.setString(6,Mobno);
          pst.setString(7,Address);
          pst.setString(8,Password1);
          pst.setString(9,Password2);


          int i = pst.executeUpdate();
          conn.commit(); 
          String msg=" ";
          if(i!=0){  
            msg="Record has been inserted";
            pw.println("<font size='6' color=blue>" + msg + "</font>");


          }  
          else{  
            msg="failed to insert the data";
            pw.println("<font size='6' color=blue>" + msg + "</font>");
           }  
          pst.close();
        }  
        catch (Exception e){  
          pw.println(e);  
        }

}

}

2.> index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"                    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form name="registrationform" action="register" method="post">
<p>
Enter your first name: <input type="text" name="fname"><br>
Enter your middle name: <input type="text" name="mname"><br>
Enter your last name: <input type="text" name="lname"><br>
</p><br>
<p>
Enter username: <input type="text" name="username"><br>
</p><br>
<p>
Enter email id: <input type="text" name="emailid"><br>
Enter mobile number: <input type="text" name="mobno"><br>
Enter address: <textarea rows="5" cols="5" name="address"></textarea><br>
</p><br>
<p>
Enter the password: <input type="password" name="password1"><br>
Reenter the password: <input type="password" name="password2"><br>
</p><br>
<p>
<input type="submit">
</p><br>
</form>
</body>
</html>

3.> web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>RegisterExample</display-name>
<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>
<servlet>
<description>Register Servlet</description>
<display-name>Register</display-name>
<servlet-name>Register</servlet-name>
<servlet-class>register.com.Register</servlet-class>  
</servlet>
<servlet-mapping>
<servlet-name>Register</servlet-name>
<url-pattern>/register</url-pattern>
</servlet-mapping>
</web-app>

4.> 我已经添加了mysql-connector-java-5.0.8-bin.jar和servlet-api-3.0.jar
来添加它。我已经在数据源资源管理器中创建了到数据库的连接。

当我进行编译或调试时，没有显示错误。在运行期间也没有错误。当我填写表格并提交时，它仅显示空白屏幕:(没有输出显示。:(同样在数据库中，值未更新。

请帮我。这个片段让我感到宿醉。

Answer 1

检查doPost()是否从jsp表单中调用了servlet的方法并删除了conn.commit。