在eclipse中使用servlet和jsp將數據插入數據庫

Question

我正在嘗試使用servlet和jsp以及MySQL Workbench作為數據庫將值添加或插入到數據庫表中。 這些是以下細節：

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.> 我添加了mysql-connector-java-5.0.8-bin.jar和servlet-api-3.0.jar是添加它所需的任何東西。 我在Data Source Explorer中創建了與數據庫的連接。

當我編譯或調試時，它沒有顯示任何錯誤。 在運行期間也沒有錯誤。 當我填寫表格並提交它只顯示空白屏幕:(沒有輸出顯示。:(也在數據庫中的值不更新。

請幫我。 我用這個片段得到了宿醉。

Answer 1

檢查從jsp表單調用servlet的doPost()方法並刪除conn.commit 。

Answer 2

你可以通過放置logger或println（）來檢查i的值。 並檢查最后關閉db conn。 休息你的代碼看起來很好，它應該工作。

Answer 3

同樣的問題在PreparedStatement獲取主要問題使用簡單語句然后你成功插入記錄同樣使用下面。

String  st2="insert into 
user(gender,name,address,telephone,fax,email,
     destination,sdate,edate,Participant,hcategory,
     Culture,Nature,People,Cities,Beaches,Festivals,username,password) 
values('"+gender+"','"+name+"','"+address+"','"+phone+"','"+fax+"',
       '"+email+"','"+desti+"','"+sdate+"','"+edate+"','"+parti+"',
       '"+hotel+"','"+chk1+"','"+chk2+"','"+chk3+"','"+chk4+"',
       '"+chk5+"','"+chk6+"','"+user+"','"+password+"')";


int i=stm.executeUpdate(st2);

Answer 4

在您的JSP <form> line <form>標記處，嘗試此代碼

<form name="registrationform" action="Register" method="post">

Answer 5

String user = request.getParameter("uname");
out.println(user); 
String pass = request.getParameter("pass");
out.println(pass); 
Class.forName( "com.mysql.jdbc.Driver" );
Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost:3306/rental","root","root" ) ;
out.println("hello");
Statement st = conn.createStatement();
String sql = "insert into login (user,pass) values('" + user + "','" + pass + "')";
st.executeUpdate(sql);

Answer 6

從Register.java中刪除conn.commit

在你的jsp更改操作中： <form name="registrationform" action="Register" method="post">

Answer 7

我有一個類似的問題，並能夠通過識別我打算使用哪個JDBC驅動程序來解決它。 就我而言，我正在連接到Oracle數據庫。 在創建連接變量之前，我放置了以下語句。

DriverManager.registerDriver（new oracle.jdbc.driver.OracleDriver（））;