Question

嗨我想在数据库中插入一些字段名称，为此我使用的是java bean，jsp和servlet但是我收到了错误。我尝试使用preparedStatement然后我尝试使用Statement但是在我得到的两种情况下错误＆gt;请指出错误在哪里。我的代码如下。我正在使用eclipse juno IDE

register1.java

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

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 com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;

import DB.DataBaseConnection;

/**
 * Servlet implementation class register
 */
@WebServlet(register1.REGISTER1)
public class register1 extends HttpServlet {
    static final String REGISTER1 = "/register1";
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public register1() {
        super();
        // TODO Auto-generated constructor 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
        PrintWriter out=response.getWriter();
        try{
        DataBaseConnection db=new DataBaseConnection();
        java.sql.Connection con= db.connet();
        String FirstName=request.getParameter("FirstName");
        String LastName=request.getParameter("LastName");
        String DOB=request.getParameter("DOB");
        String Qualification=request.getParameter("Qualification");
        String RegistrationNo=request.getParameter("RegistrationNo");
        String CountryOfRegistration=request.getParameter("CountryOfRegistration");
        String PracticeName=request.getParameter("PracticeName");
        String Phone=request.getParameter("Phone");
        String Email=request.getParameter("Email");
        String Address=request.getParameter("Address");
        String Street=request.getParameter("Street");
        String City=request.getParameter("City");
        String State=request.getParameter("State");
        String Country=request.getParameter("Country");
        String PinCode=request.getParameter("PinCode");
        String HowDoYouKnow=request.getParameter("HowDoYouKnow");
        String Comments=request.getParameter("Comments");


out.println(FirstName);







        //ps = (PreparedStatement) con.prepareStatement("insert into registration values(?,?,?)");
Statement st=con.createStatement();
st.executeUpdate("insert into registration values(v,v,v,v,v,v,v,v,v,v,v,v,v,v,v,v,v)");
//      PreparedStatement ps=(PreparedStatement) con.prepareStatement("insert into registration values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
//      out.println(FirstName);
//
//  ps.setString(1, FirstName);
//  out.println(FirstName);
//
//  ps.setString(2,LastName);
//  ps.setString(3,DOB);
//  out.println(FirstName);
//
//  ps.setString(4,Qualification);
//  ps.setString(5, RegistrationNo);
//  ps.setString(6, CountryOfRegistration);
//  ps.setString(7, PracticeName);
//  ps.setString(8, Phone);
//  ps.setString(9, Email);
//  ps.setString(10, Address);
//  ps.setString(11, Street);
//  ps.setString(12, City);
//  ps.setString(13, State);
//  ps.setString(14, Country);
//  ps.setString(15, PinCode);
//  ps.setString(16, HowDoYouKnow);
//  ps.setString(17, Comments);
//  ps.executeUpdate();

    }
    catch(Exception e)
    {
        e.printStackTrace();
    }

}
}

的JavaBean

package register;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
import com.mysql.jdbc.Statement;

import DB.DataBaseConnection;
public class registration {


        private String FirstName;
        private String LastName;
        private String DOB;
        private String Qualification;
        private String RegistrationNo;
        private String CountryOfRegistration;
        private String PracticeName;
        private String Phone;
        private String Email;
        private String Address;
        private String Street;
        private String City;
        private String State;
        private String Country;
        private String PinCode;
        private String HowDoYouKnow;
        private String Comments;
        public registration()
        {
            this.FirstName=FirstName;
            this.LastName=LastName;
            this.DOB=DOB;
            this.Qualification=Qualification;
            this.RegistrationNo=RegistrationNo;
            this.CountryOfRegistration=CountryOfRegistration;
            this.PracticeName=PracticeName;
            this.Phone=Phone;
            this.Email=Email;
            this.Address=Address;
            this.Street=Street;
            this.City=City;
            this.State=State;
            this.Country=Country;this.PinCode=PinCode;this.HowDoYouKnow=HowDoYouKnow;   
            this.Comments=Comments;
        }
        public void setFirstName(String FirstName)
        {
            this.FirstName=FirstName;
        }
        public String getFirstName()
        {
            return FirstName;
        }
        public void setLastName(String LastName)
        {
            this.LastName=LastName;
        }
        public String getLastName()
        {
            return LastName;
        }public void setDOB(String DOB)
        {
            this.DOB=DOB;
        }
        public String getDOB()
        {
            return DOB;
        }public void setQualification(String Qualification)
        {
            this.Qualification=Qualification;
        }
        public String getQualification()
        {
            return Qualification;
        }public void setRegistrationNo(String RegistrationNo)
        {
            this.RegistrationNo=RegistrationNo;
        }
        public String getRegistrationNo()
        {
            return RegistrationNo;
        }public void setCountryOfRegistration(String CountryOfRegistration)
        {
            this.CountryOfRegistration=CountryOfRegistration;
        }
        public String getCountryOfRegistration()
        {
            return CountryOfRegistration;
        }public void setPracticeName(String PracticeName)
        {
            this.PracticeName=PracticeName;
        }
        public String getPracticeName()
        {
            return PracticeName;
        }public void setPhone(String Phone)
        {
            this.Phone=Phone;
        }
        public String getPhone()
        {
            return Phone;
        }public void setEmail(String Email)
        {
            this.Email=Email;
        }
        public String getEmail()
        {
            return Email;
        }public void setAddress(String Address)
        {
            this.Address=Address;
        }
        public String getAddress()
        {
            return Address;
        }public void setStreet(String Street)
        {
            this.Street=Street;
        }
        public String getStreet()
        {
            return Street;
        }public void setCity(String City)
        {
            this.City=City;
        }
        public String getCity()
        {
            return City;
        }public void setState(String State)
        {
            this.State=State;
        }
        public String getState()
        {
            return State;
        }public void setCountry(String Country)
        {
            this.Country=Country;
        }
        public String getCountry()
        {
            return Country;
        }public void setPinCode(String PinCode)
        {
            this.PinCode=PinCode;
        }
        public String getPinCode()
        {
            return PinCode;
        }public void setHowDoYouKnow(String HowDoYouKnow)
        {
            this.HowDoYouKnow=HowDoYouKnow;
        }
        public String getHowDoYouKnow()
        {
            return HowDoYouKnow;
        }public void setComments(String Comments)
        {
            this.Comments=Comments;
        }
        public String getComments()
        {
            return Comments;
        }
        public String insert() throws ClassNotFoundException 
        {
            String output="";
        //public void insert(String FirstName,String LastName,String DOB) throws SQLException
        //{
        //DataBaseConnection db= new DataBaseConnection();
        //Connection con =(Connection) db.connet();
        //PreparedStatement ps=(PreparedStatement) con.prepareStatement("insert into registration values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
        //PreparedStatement ps;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con=(Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/test","sukanth","");
            //ps = (PreparedStatement) con.prepareStatement("insert into registration values(?,?,?)");
            PreparedStatement ps=(PreparedStatement) con.prepareStatement("insert into registration values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");

        ps.setString(1, FirstName);
        ps.setString(2,LastName);
        ps.setString(3,DOB);

        ps.setString(4,Qualification);
        ps.setString(5, RegistrationNo);
        ps.setString(6, CountryOfRegistration);
        ps.setString(7, PracticeName);
        ps.setString(8, Phone);
        ps.setString(9, Email);
        ps.setString(10, Address);
        ps.setString(11, Street);
        ps.setString(12, City);
        ps.setString(13, State);
        ps.setString(14, Country);
        ps.setString(15, PinCode);
        ps.setString(16, HowDoYouKnow);
        ps.setString(17, Comments);
        ps.executeUpdate();
        output="sucess";

        }
        catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            output=e.toString();
        }
        /*public static void main(String args[]) throws SQLException
        {
            registration r=new registration();
            r.insert("s","k","n");
        }*/
        return output;
    }
//      public static void main(String args[]) throws SQLException, ClassNotFoundException
//      {
//          registration r=new registration();
//          r.insert();
//      }

}

数据取自此jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head><jsp:useBean id="registration" class="register.registration" scope="request">
<jsp:setProperty property="*" name="registration"/></jsp:useBean>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action ="register1" method="post">
FirstName<input type="text" name="FirstName">Lastname<input type="text" name="LastName"><br>
DOB<input type="text" name="DOB">Qualification<input type="text" name="Qualification"><br>
RegistrationNo<input type="text" name="RegistrationNo">CountryOfRegistration<input type="text" name="CountryOfRegistration"><br>
PracticeName<input type="text" name="PracticeName">Phone<input type="text" name="Phone"><br>
Email<input type="text" name="Email">Address<input type="text" name="Address"><br>
Street<input type="text" name="Street">City<input type="text" name="City"><br>
State<input type="text" name="State">Country<input type="text" name="Country"><br>
PinCode<input type="text" name="PinCode">HowDoYouKnow<input type="text" name="HowDoYouKnow"><br>
Comments<input type="text" name="Comments"><br>
<input type ="submit" name ="submit">
<input type="reset" name="reset">

</form>
</body>
</html>

这是错误

Mar 26, 2013 5:48:53 AM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/jre/lib/i386/client:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/jre/lib/i386:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/jre/../lib/i386:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/jre/lib/i386/client:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/jre/lib/i386::/usr/java/packages/lib/i386:/lib:/usr/lib
Mar 26, 2013 5:48:54 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:project1' did not find a matching property.
Mar 26, 2013 5:48:54 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:project2' did not find a matching property.
Mar 26, 2013 5:48:54 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:project3' did not find a matching property.
Mar 26, 2013 5:48:54 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Mar 26, 2013 5:48:54 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
Mar 26, 2013 5:48:54 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 2844 ms
Mar 26, 2013 5:48:55 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Mar 26, 2013 5:48:55 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.37
Mar 26, 2013 5:48:55 AM org.apache.catalina.util.SessionIdGenerator createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [117] milliseconds.
Mar 26, 2013 5:48:56 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Mar 26, 2013 5:48:56 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
Mar 26, 2013 5:48:56 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 1493 ms
java.lang.NullPointerException
    at register1.doPost(register1.java:77)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:679)
java.lang.NullPointerException
    at register1.doPost(register1.java:77)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:679)
java.lang.NullPointerException
    at register1.doPost(register1.java:77)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:679)
java.lang.NullPointerException
    at register1.doPost(register1.java:77)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:679)

这是DataBaseConnection类

package DB;
import  java.sql.*;
public class  DataBaseConnection
{public static void main(String[] args) throws SQLException, ClassNotFoundException
    {

    DataBaseConnection db= new DataBaseConnection();
    Connection  con=db.connet();
        if(!con.isClosed())
        {
            System.out.println("connectedn");
        }
        }
public Connection connet() 
{
    Connection con=null;

    try
    {
Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","sukanth","");
return con;
    }
    catch(Exception e)
    {
        return  con;
    }



}
}

Answer 1

java.lang.NullPointerException
    at register1.doPost(register1.java:77)

该错误明确暗示{/ 1}}

NullPointerException

修改后的DataBaseConnection.java

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        PrintWriter out=response.getWriter();
        try{
        DataBaseConnection db=new DataBaseConnection();
        java.sql.Connection con= db.connet();
        //...... 
       //Statement st=con.createStatement(); // This may be the root cause of exception
       // check null here
      if(con!=null){
        // create statement or prepared statement
      }  
}

另外，请确保您的CLASSPATH中有package DB; import java.sql.*; public class DataBaseConnection { public Connection connet() { Connection con=null; try { Class.forName("com.mysql.jdbc.Driver"); con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","sukanth",""); } catch(Exception e) { e.printStacktrace(); } return con; } }。在mysqljdbc.jar复制mysqljdbc.jar。

Answer 2

您尚未提供Class.forName()来加载Register1.java

中的驱动程序

Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","sukanth","");
Statement st=con.createStatement();
//remaining codes

确保在JSP页面中提供所有值。并且还要确保数据库中的DOB字段是字符串，如果没有将servlet中的DOB字段转换为日期格式

Answer 3

I think you simply mixed up the code. You put the connection and insertion related logic in your注册类, then what is there in DataBaseConnection class and what is its role? You are not clear with this code. Whatever注册类insetrt（）method is doing the same you are doing in doPost（ - ， - ）`servlet方法。

我认为不需要使用bean类来设置和获取表单组件值。只需要一个包含两个方法的bean类，一个用于建立数据库连接，另一个用于释放连接。在servlet的doGet（ - ， - ）方法中创建其对象，并使用request.getParameter（ - ）读取所有表单组件值并使用pstmnt.setXxx（）将这些值设置为查询的占位符，然后只执行查询。成功执行后，调用bean类的第二个方法来释放连接。

试试这个，我希望它会有所帮助...

    //write a bean class in some package(p1)
    package p1;
    //import all required classes/interfaces
    public class DBConn{
    private Connection con;
    public Connection getConnection() throws SQLException{
    Class.forName("com.mysql.jdbc.Driver");
    con= DriverManager.getConnection("jdbc:mysql://host_ipaddress:port no./sid","username","password");
    return con;
    }

    public void releaseConnection() throws SQLException{

     if(con!=null)
     con.close();
      }
    }

//Take a form page(jsp/html) same as you have....

//write a servlet to insert the form page data in DB..


//import all classes and interfaces here...
public class register1 extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response) {
  try{  
        // set content type and get an output stream...      
        response.setContentType("text/html");
        PrintWriter out=response.getWriter();

        //create bean class object and get a connection object...
        DBConn db=new DBConn();
        java.sql.Connection con= db.getConnection();

        // read all request parameter values from request...
        String FirstName=request.getParameter("FirstName");
        String LastName=request.getParameter("LastName");
        String DOB=request.getParameter("DOB");
        String Qualification=request.getParameter("Qualification");
        String RegistrationNo=request.getParameter("RegistrationNo");
        String CountryOfRegistration=request.getParameter("CountryOfRegistration");
        String PracticeName=request.getParameter("PracticeName");
        String Phone=request.getParameter("Phone");
        String Email=request.getParameter("Email");
        String Address=request.getParameter("Address");
        String Street=request.getParameter("Street");
        String City=request.getParameter("City");
        String State=request.getParameter("State");
        String Country=request.getParameter("Country");
        String PinCode=request.getParameter("PinCode");
        String HowDoYouKnow=request.getParameter("HowDoYouKnow");
        String Comments=request.getParameter("Comments");

        // get a pre-compiled query with the help of PreparedStatement ...
        PreparedStatement ps =con.prepareStatement("insert into <table name>
values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");

   //set the place holder parameters values to the pre-compiled query..
    ps.setString(1, FirstName);
    ps.setString(2,LastName);
    ps.setString(3,DOB);
    ps.setString(4,Qualification);
    ps.setString(5, RegistrationNo);
    ps.setString(6, CountryOfRegistration);
    ps.setString(7, PracticeName);
    ps.setString(8, Phone);
    ps.setString(9, Email);
    ps.setString(10, Address);
    ps.setString(11, Street);
    ps.setString(12, City);
    ps.setString(13, State);
    ps.setString(14, Country);
    ps.setString(15, PinCode);
    ps.setString(16, HowDoYouKnow);
    ps.setString(17, Comments);
  int counter= ps.executeUpdate();

    if(counter>0)
    {
     out.println("Values inserted successfully...");
    db.releaseConnection();
    }
  else if(counter<=0)
   {
    out.println("Something went wrong, Values couldn't inserted in DB..");
    db.releaseConnection();
   }

    }
    catch(SQLException sqle)
    {
        sqle.printStackTrace();
    }
   catch(ServletException se)
   {
   se.printStackTrace();
    }
   catch(IOException ie)
   {
    ie.printStackTrace();
   }
   catch(Exception e)
   {
    e.printStackTrace();
   }

  }//doGet(-,-) closing.....

  protected void doPost(HttpServletRequest request, HttpServletResponse response) {
     doGet(request,response);
    }//doPost(-,-) closing...
}// servlet class closing...

//不要忘记使用URL映射servlet，并在表单页面上使用与表单标记的操作值相同的内容，以及在应用程序的类路径和lib文件夹中使用MYSQL相关的Connector / J jar文件或服务器的lib文件夹（如果将它放在应用程序的lib文件夹中，则更好）。希望你能清楚。

尝试使用servlet和jsp插入mysql时出错

3 个答案: