BBS论坛留言板servlet+jsp+jdbc+mysql

由于代码较多，这里只给出几个模块的代码，想看全部代码请点击链接：
http://download.csdn.net/detail/broccoli2/9874505

DBUtils.java

package dbUtils;

import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Time;
import java.util.ArrayList;
import java.util.List;

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

import entity.Message;

public class DBUtils {

    public static Connection getConn() {
        String driver = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/bbs";
        String username = "root";
        String password = "123456";
        Connection conn = null;
        try {
            Class.forName(driver); //classLoader,加载对应驱动
            conn = (Connection) DriverManager.getConnection(url, username, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }



    public static int insert(String username,String password) {
        Connection conn = getConn();
        int i = 0;
        String sql = "insert into user (username,password) values(?,?)";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement) conn.prepareStatement(sql);
           // pstmt.setInt(1, 2);
            pstmt.setString(1, username);
            pstmt.setString(2, password);
            i = pstmt.executeUpdate();
            pstmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return i;
    }

    public static Integer getAUser(String username,String password) {
        Connection conn = getConn();
        String sql = "select * from user where username=? and password=?";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement)conn.prepareStatement(sql);
            pstmt.setString(1, username);
            pstmt.setString(2, password);
            ResultSet rs = (ResultSet) pstmt.executeQuery();




            /*System.out.println("============================"); while (rs.next()) { System.out.print(rs.getInt("id") + "\t"); System.out.print(rs.getString("username") + "\t"); System.out.println(rs.getString("password") + "\t"); } System.out.println("============================");*/
            System.out.println("查询数据成功!");

            if(rs.next()){
                return 1;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }


    public static boolean insertMessage(String username,String subject,String content,String notetime,String ntime){

        Connection conn = getConn();
        String sql = "insert into message (noteuser,subject,content,notetime,ntime) values(?,?,?,?,?)";
        PreparedStatement pstmt;
        try {
            pstmt = (PreparedStatement)conn.prepareStatement(sql);
            pstmt.setString(1, username);
            pstmt.setString(2, subject);
            pstmt.setString(3, content);
            pstmt.setString(4, notetime);
            pstmt.setString(5, ntime);
            int i = pstmt.executeUpdate();
        if(i != 0){
            System.out.println("留言成功!");
            return true;
        }

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

        return false;
    }


    public static List<Message> getAllMessage(){
        Connection conn = getConn();
        String sql = "select * from message";
        PreparedStatement pstmt;
        List<Message> list = new ArrayList<Message>();
        try {
            pstmt = (PreparedStatement)conn.prepareStatement(sql);

            ResultSet rs = (ResultSet) pstmt.executeQuery();
            while(rs.next()){
                Message message = new Message();
                message.setNoteuser(rs.getString("noteuser"));
                message.setSubject(rs.getString("subject"));
                message.setContent(rs.getString("content"));
                message.setNotetime(rs.getDate("notetime"));
                message.setNtime(rs.getTime("ntime"));
                list.add(message);
            }

            return list;
           /* while (rs.next()) { System.out.print(rs.getString("noteuser") + "\t"); System.out.print(rs.getString("subject") + "\t"); System.out.println(rs.getString("content") + "\t"); }*/
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    //返回记录数目
    public static int  count(){
        Connection conn = getConn();
        String sql = "select count(*) from message";
        PreparedStatement pstmt;
        int i = 0;
        try {
            pstmt = (PreparedStatement)conn.prepareStatement(sql);
            i = pstmt.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return i;
    }



    public static boolean deleteMessage(String notetime){
        Connection conn = getConn();
        String sql = "delete from message where ntime=?";
        PreparedStatement pstmt;

        try {
            pstmt = (PreparedStatement)conn.prepareStatement(sql);
            pstmt.setString(1, notetime);
            int re = pstmt.executeUpdate();
            if(re>0){
                return true;
            }


        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        finally{
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return false;
    }


}

后太使用的是servlet。
LoginAction.java

package action;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import dbUtils.DBUtils;
import entity.Message;

public class LoginAction extends HttpServlet {

    /** * Constructor of the object. */
    public LoginAction() {
        super();
    }

    /** * Destruction of the servlet. <br> */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");
        request.setCharacterEncoding("UTF-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        //System.out.println(username+":"+password);

        HttpSession session = request.getSession(); 
        //request.setAttribute("username", username);




        session.setAttribute("username", username);
        System.out.println(session.getAttribute("username"));


        DBUtils.getConn();
        Integer temp = DBUtils.getAUser(username, password);
        if(temp!=null){
            List<Message> list = DBUtils.getAllMessage();
            session.setAttribute("messageList", list);
            //System.out.println(list.listIterator());
            /*Message m = list.get(0); System.out.println(m.getContent()+"*************");*/
            response.sendRedirect("home.jsp");
        }




        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML>");
        out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println(" <BODY>");
        out.println("请输入正确的用户名和密码！ ");
        out.println(" </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML>");
        out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println(" <BODY>");
        out.print(" This is ");
        out.print(this.getClass());
        out.println(", using the POST method");
        out.println(" </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    /** * Initialization of the servlet. <br> * * @throws ServletException if an error occurs */
    public void init() throws ServletException {
        // Put your code here
    }

}

ManagerAction.java

package action;

import java.io.IOException;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import dbUtils.DBUtils;
import entity.Message;

public class MessageAction extends HttpServlet {

    /** * */
    private static final long serialVersionUID = 1L;

    /** * Constructor of the object. */
    public MessageAction() {
        super();
    }

    /** * Destruction of the servlet. <br> */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");

        String method = request.getParameter("method");
        String ntime2 = request.getParameter("ntime");
        /*System.out.println(method+":method"); System.out.println(ntime2+":notetime");*/
        HttpSession session = request.getSession(); 

        if(method.equals("deleteNote")){
            DBUtils.deleteMessage(ntime2);
            List<Message> list = DBUtils.getAllMessage();
            session.setAttribute("messageList", list);
            response.sendRedirect("home.jsp");
        }

        String subject = request.getParameter("subject");
        String content = request.getParameter("content");

        if(method.equals("addMessage")){

          SimpleDateFormat dft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
          Date beginDate = new Date();
          Calendar date = Calendar.getInstance();
          date.setTime(beginDate);
          date.set(Calendar.DATE,date.get(Calendar.DATE));
          String today = dft.format(date.getTime());  
    //System.out.println(today+"&&&&&&&&&&&&&&&&&&&");

        Date ctime = new Date();
        /*DateFormat df3 = DateFormat.getTimeInstance();//只显示出时分秒 Calendar cal = Calendar.getInstance(); int hour=cal.get(Calendar.HOUR);//小时 int minute=cal.get(Calendar.MINUTE);//分 int second=cal.get(Calendar.SECOND);//秒 */     
       long ms = ctime.getTime();



        SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss");
        String ntime = formatter.format(ms);
        //System.out.println(ntime+"**************");


        String username = (String) session.getAttribute("username");

        if(DBUtils.insertMessage(username,subject, content,today,ntime)){
            List<Message> list = DBUtils.getAllMessage();
            session.setAttribute("messageList", list);
            response.sendRedirect("home.jsp");
        }

        }




    }

    /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML>");
        out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println(" <BODY>");
        out.print(" This is ");
        out.print(this.getClass());
        out.println(", using the POST method");
        out.println(" </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    /** * Initialization of the servlet. <br> * * @throws ServletException if an error occurs */
    public void init() throws ServletException {
        // Put your code here
    }

}

home.jsp

<%@ page language="java" import="java.util.*,entity.Message" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'home.jsp' starting page</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!-- <link rel="stylesheet" type="text/css" href="styles.css"> -->

  </head>

  <body>
  <div align="center">
  <h1>留言板</h1>
  <table border="1px" width="50%" cellspacing="0" cellpadding="0" bordercolor="#F0F0F0" bordercolorlight="#F0F0F0" bordercolordark="white">
    <tr>
    <td>留言人</td>
    <td>留言主题</td>
    <td>留言内容</td>
    <td>留言时间</td>
    <td>操作</td>
    </tr>
    <c:if test="${not empty messageList}">
    <c:forEach var="message" items="${messageList}" varStatus="status">
    <tr>
    <td>${message.noteuser}</td>
    <td>${message.subject}</td>
    <td>${message.content}</td>
    <td>${message.notetime}&nbsp${message.ntime}</td>
    <td><a href="messageAction?ntime=${message.ntime}&method=deleteNote">删除</a></td>
    </tr>
    </c:forEach>
  </c:if>
  </table>
  <a href="addMessage.jsp">添加留言</a>

  </div>
  </body>
</html>

实体类：
Mssage.java

package entity;

import java.io.Serializable;
import java.sql.Time;
import java.util.Date;

public class Message implements Serializable{

    private String noteuser;
    private String subject;
    private String content;
    private Date notetime;
    private Time ntime;
    public String getNoteuser() {
        return noteuser;
    }
    public void setNoteuser(String string) {
        this.noteuser = string;
    }
    public String getSubject() {
        return subject;
    }
    public void setSubject(String subject) {
        this.subject = subject;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public Date getNotetime() {
        return notetime;
    }
    public void setNotetime(Date notetime) {
        this.notetime = notetime;
    }
    public Time getNtime() {
        return ntime;
    }
    public void setNtime(Time ntime) {
        this.ntime = ntime;
    }   
}