短消息论坛

一.搭好架构

1.1导入basedao

package cn.jbit.demo.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

public class BaseDao {

    protected Connection con = null;
    protected PreparedStatement ps = null;
    protected ResultSet rs = null;
    
    
    public static final String driver="com.mysql.jdbc.Driver";
    public static final String url="jdbc:mysql://localhost:3306/message";
    public static final String username="root";
    public static final String password="1234";
       public void openConnection(){
           try {
            Class.forName(driver);
             if(con==null||con.isClosed()){
                 con=DriverManager.getConnection(url,username,password);
             }
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }
       }

    //获取连接
    protected void openConnection2(){
            try {
                Context ctx = new InitialContext();
                DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/Message");
                con = ds.getConnection();
            } catch (NamingException e) {
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }
    }    
    
    //更新新据库
    public int executeUpdata(String sql, List<Object> list){        
        openConnection();
        try {
            ps = con.prepareStatement(sql);
            if(list == null)
                return ps.executeUpdate();
            int i = 1;
            for(Object obj:list){
                ps.setObject(i, obj);
                i++;
            }
            return ps.executeUpdate();
        } catch (SQLException e) {            
            e.printStackTrace();
        }finally{
            closeResource();
        }
        return 0;
    }
    
    //关闭流
    protected void closeResource(){        
    try {
        if(rs != null)
            rs.close();
        if(ps != null)
            ps.close();
        if(con != null)
            con.close();
        
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
}

二.登录,注册页面

2.1 UserInfo中的代码:

package cn.jbit.demo.entity;

public class UserInfo{

    private String username = null;//用户名
    private String password = null;//密码
    private String email = null;//电子邮箱
    
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

2.2 UserinfoDao

package cn.jbit.demo.dao;

import java.util.List;
import java.util.Map;

import cn.jbit.demo.entity.UserInfo;

public interface UserinfoDao {
    //查找用户
    public List<UserInfo> getUsers(Map<String,String> contitions);
    //添加或更新用户
    public int executeUpdate(String operate, UserInfo userinfo);
}

2.3 UserinfoDaoImpl

package cn.jbit.demo.dao.impl;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import cn.jbit.demo.dao.BaseDao;
import cn.jbit.demo.dao.UserinfoDao;
import cn.jbit.demo.entity.UserInfo;

public class UserinfoDaoImpl extends BaseDao implements UserinfoDao {
    
    //添加或更新用户
    public int executeUpdate(String operate, UserInfo userinfo) {
        List<Object> list = null;
        String sql = null;
        if(operate.equals("update")){
            sql = "update msg_userinfo set password=? where username = '" + userinfo.getUsername() + "'";
            list = new ArrayList<Object>();
            list.add(userinfo.getPassword());
        }else if(operate.equals("insert")){
            sql = "insert into msg_userinfo values(?,?,?)";
            list = new ArrayList<Object>();
            list.add(userinfo.getUsername());
            list.add(userinfo.getPassword());
            list.add(userinfo.getEmail());
        }
        return executeUpdata(sql, list);
    }

    //查找用户
    public List<UserInfo> getUsers(Map<String,String> contitions) {
        String username = (String) contitions.get("username");
        String pwd = (String) contitions.get("pwd");
        String operate = (String)contitions.get("operate");
        String sql = "select * from msg_userinfo where 1=1 ";
        if(operate != null && operate.equals("except")){
            sql += username != null ? " and username != '" + username + "'":"";
        }else{
            sql += username != null ? " and username = '" + username + "'":"";
        }
        sql += pwd != null ? " and password = '" + pwd + "'":"";
        openConnection();
        List<UserInfo> users = new ArrayList<UserInfo>();
        try {
            ps = con.prepareStatement(sql);
            rs = ps.executeQuery();
            while(rs.next()){
                UserInfo uf = new UserInfo();
                uf.setUsername(rs.getString("username"));
                uf.setPassword(rs.getString("password"));
                uf.setEmail(rs.getString("email"));
                users.add(uf);                
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            closeResource();
        }        
        return users;
    }
}

2.4  UserInfoBiz

package cn.jbit.demo.biz;

import java.util.List;
import java.util.Map;

import cn.jbit.demo.entity.UserInfo;

public interface UserInfoBiz {
    //查找用户
    public List<UserInfo> findUser(Map<String,String> elements);
    //添加或更新用户
    public int doInsertOrUpdateUser(String operate, UserInfo userinfo);
}

2.5 UserInfoBizImpl

package cn.jbit.demo.biz.impl;

import java.util.List;
import java.util.Map;

import cn.jbit.demo.biz.UserInfoBiz;
import cn.jbit.demo.dao.UserinfoDao;
import cn.jbit.demo.dao.impl.UserinfoDaoImpl;
import cn.jbit.demo.entity.UserInfo;

public class UserInfoBizImpl implements UserInfoBiz {

    private UserinfoDao userinfoDao = new UserinfoDaoImpl();

    //添加或更新用户
    public int doInsertOrUpdateUser(String operate, UserInfo userinfo) {
        
        return userinfoDao.executeUpdate(operate, userinfo);
    }

    //查找用户
    public List<UserInfo> findUser(Map<String,String> elements) {
        
        return userinfoDao.getUsers(elements);
    }
}

2.6 UserServlet

package cn.jbit.demo.web;

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

import cn.jbit.demo.biz.UserInfoBiz;
import cn.jbit.demo.biz.impl.UserInfoBizImpl;
import cn.jbit.demo.entity.UserInfo;

public class UserServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String action = request.getParameter("action");
        UserInfoBiz userInfoBiz=new UserInfoBizImpl();
        if ("login".equals(action)) {//登录
            String username = request.getParameter("username");
            String password = request.getParameter("password");            
            Map<String,String> contitions = new HashMap<String,String>();
              contitions.put("username", username);
              contitions.put("pwd", password);
            List <UserInfo>list = userInfoBiz.findUser(contitions);
            if(list == null || list.size() != 1){
                request.setAttribute("error", "用户名或密码错误！");
                  request.getRequestDispatcher("index.jsp").forward(request,response);    
            }else{
                request.getSession().setAttribute("loginuser", username);
                response.sendRedirect("MsgServlet?action=list");
            }  
        }else if("regist".equals(action)){//注册
            String username = request.getParameter("username");
              String password = request.getParameter("password");
              String email = request.getParameter("email");              
              Map<String,String> conditions = new HashMap<String,String>();
              conditions.put("username", username);
              List <UserInfo>list = userInfoBiz.findUser(conditions);
              if(list.size() > 0){                      
                  request.setAttribute("error", "此用户名已被注册");                  
                  request.getRequestDispatcher("register.jsp").forward(request,response);
              }else{
                  UserInfo uf = new UserInfo();
                  uf.setUsername(username);
                  uf.setPassword(password);
                  uf.setEmail(email);
                  int isRun = userInfoBiz.doInsertOrUpdateUser("insert", uf);
                  if(isRun > 0){
                      request.setAttribute("error", "已经成功注册！");
                      request.getRequestDispatcher("index.jsp").forward(request,response);                      
                  }
              }
        }else if("logout".equals(action)){//退出
            request.getSession().removeAttribute("loginuser");
            response.sendRedirect("index.jsp");
        }else if("findUsers".equals(action)){//查找其它所有的用户            
             String username = (String)request.getSession().getAttribute("loginuser");      
             Map <String,String>contitions = new HashMap<String,String>();
             contitions.put("username", username);
             contitions.put("operate","except");
             List<UserInfo> list = userInfoBiz.findUser(contitions);
             request.setAttribute("users", list);
             request.getRequestDispatcher("newMsg.jsp").forward(request,response);
        }
    }
}

 三.信息页面

3.1 BBSMessage

package cn.jbit.demo.entity;

import java.util.Date;

public class BBSMessage{

    private String msgid = null;//ID
    private String username = null;//发送方
    private String title = null;//标题
    private String content = null;//内容
    private int state = 0;//用户名
    private String sendto=null;//收件方
    private Date datetime = null;//发送时间
    public String getMsgid() {
        return msgid;
    }
    public void setMsgid(String msgid) {
        this.msgid = msgid;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public int getState() {
        return state;
    }
    public void setState(int state) {
        this.state = state;
    }
    public String getSendto() {
        return sendto;
    }
    public void setSendto(String sendto) {
        this.sendto = sendto;
    }
    public Date getDatetime() {
        return datetime;
    }
    public void setDatetime(Date datetime) {
        this.datetime = datetime;
    }
}

 3.2 BBSMessageDao

package cn.jbit.demo.dao;

import java.util.List;
import java.util.Map;

import cn.jbit.demo.entity.BBSMessage;

public interface BBSMessageDao {
    //查询短信息
    public List<BBSMessage>  getMessagesByPage(Map<String,Object> elements);
    //更新短信息
    public int executeUpdate(String operate, Map<String,Object> elements, Map<String,Object> conditions);
    //获取短信条数
    public int getMsgsCount(String username);
}

3.3 BBSMessageDaoImpl

package cn.jbit.demo.dao.impl;

import java.sql.SQLException;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

import cn.jbit.demo.dao.BBSMessageDao;
import cn.jbit.demo.dao.BaseDao;
import cn.jbit.demo.entity.BBSMessage;

public class BBSMessageDaoImpl extends BaseDao implements BBSMessageDao {
    /*
     * 执行update操作
     * @param
     *     operate：执行插入、更新还是删除
     *     elements：需要插入或者更新的值集合，key对应column，value是插入或者更新的值
     *     conditions：update执行的条件集合，key对应column，value是条件值
     */
    public int executeUpdate(String operate, Map <String,Object>elements, Map <String,Object>conditions) {
        List<Object> list = null;
        String sql = null;
        String msgid= null ,username= null,title= null,msgcontent= null,state= null,sendto= null;
        Date msg_create_date=null;
        /*
         * 获取需要变更的值
         */
        if(elements!=null && elements.size()>0){
            msgid = (String)elements.get("msgid");
            username = (String)elements.get("username");
            title = (String)elements.get("title");
            msgcontent = (String)elements.get("msgcontent");
            state = (String)elements.get("state");
            sendto = (String)elements.get("sendto");
            msg_create_date = (Date)elements.get("msg_create_date");        
        }
        
        
        
        /*
         * 更新操作
         */
        if(operate.equals("update")){
            /*
             * 拼写更新sql
             */
            sql = "update msg set ";
            /*
             * 获取条件元素
             */
            String ctn_msgid = (String)conditions.get("msgid");
            String ctn_username = (String)conditions.get("username");
            String ctn_title = (String)conditions.get("title");
            String ctn_msgcontent = (String)conditions.get("msgcontent");
            String ctn_state = (String)conditions.get("state");
            String ctn_sendto = (String)conditions.get("sendto");
            Date ctn_msg_create_date = (Date)conditions.get("msg_create_date");
            /*
             * 写出sql更新语句
             */
            String and = "";
            sql += msgid!=null ? and + " msgid=? ":"";
            and = msgid!=null ? " and ":"";
            sql += username!=null ? and + " username=? ":"";
            and = username!=null ? " and ":"";
            sql += title!=null ? and + " title='" + title + "' ":"";
            and = title!=null ? " and ":"";
            sql += msgcontent!=null ? and + " msgcontent=? ":"";
            and = msgcontent!=null ? " and ":"";
            sql += sendto!=null ? and + " sendto=? ":"";
            and = sendto!=null ? " and ":"";
            sql += state!=null ? and + " state=? ":"";
            and = state!=null ? " and ":"";
            sql += msg_create_date != null ? and + " msg_create_date=? ":"";
            /*
             * 写出sql条件语句
             */    
            sql = sql + " where 1=1 ";
            sql += ctn_msgid != null ? " and msgid=? ":"";
            sql += ctn_username != null ? " and username=? ":"";
            sql += ctn_title != null ? " and title='" + title + "' ":"";
            sql += ctn_msgcontent != null ? " and msgcontent=? ":"";
            sql += ctn_sendto != null ? " and sendto=? ":"";
            sql += ctn_state != null ? " and state=? ":"";
            sql += ctn_msg_create_date != null ? " and msg_create_date=? ":"";
            
            list = new ArrayList<Object>();
            /*
             * 设置更新参数
             */
            if(msgid != null)
                list.add(msgid);
            if(username != null)
                list.add(username);
            if(title != null)
                list.add(title);
            if(msgcontent != null)
                list.add(msgcontent);
            if(sendto != null)
                list.add(sendto);
            if(state != null)
                list.add(state);
            if(msg_create_date != null)
                list.add(new Timestamp(msg_create_date.getTime()));
            /*
             * 设置条件参数
             */
            if(ctn_msgid != null)
                list.add(ctn_msgid);
            if(ctn_username != null)
                list.add(ctn_username);
            if(ctn_title != null)
                list.add(ctn_title);
            if(ctn_msgcontent != null)
                list.add(ctn_msgcontent);
            if(ctn_sendto != null)
                list.add(ctn_sendto);
            if(ctn_state != null)
                list.add(ctn_state);
            if(ctn_msg_create_date != null)
                list.add(new Timestamp(ctn_msg_create_date.getTime()));
        }
        /*
         * 添加操作
         */
        else if(operate.equals("insert")){
            sql = "insert into msg values(?,?,?,?,?,?,?)";
            list = new ArrayList<Object>();
            list.add(msgid);
            list.add(username);
            list.add(title);
            list.add(msgcontent);
            list.add(state);
            list.add(sendto);
            list.add(new Timestamp(msg_create_date.getTime()));
        }
        /*
         * 删除操作
         */
        else if(operate.equals("delete")){
            sql = "delete from msg where msgid = ?";
            list = new ArrayList<Object>();
            msgid = (String)conditions.get("msgid");
            list.add(msgid);
        }
        return executeUpdata(sql, list);
    }
    /*
     * 执行查询操作
     * @param
     *     elements：查询条件集合     
     */    
    public List<BBSMessage> getMessagesByPage(Map<String,Object> elements) {        
        /*
         * 获取查询语句中的条件参数
         */        
        Integer msgs_in_one_page = (Integer)elements.get("msgs_in_one_page");
        Integer page_no = (Integer)elements.get("page_no");
        String username = (String)elements.get("username");
        String msgid = (String)elements.get("msgid");
        String title = (String)elements.get("title");
        String msgcontent = (String)elements.get("msgcontent");
        String sendto = (String)elements.get("sendto");
        Integer state = (Integer)elements.get("state");
        Date msg_create_date = (Date)elements.get("msg_create_date");
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");        
        /*
         * 拼写sql
         */
        String sql = null;        
        if(page_no == null){
            sql = "select * from msg where 1 = 1 ";
        }else{                    
            sql = "select * from" +
            "(select msg.*,rownum r from msg where 1=1 and " + 
            username + title + msgcontent + sendto + state + msg_create_date + 
            " and rownum <= " + msgs_in_one_page*page_no + ") " +
            "t where t.r >" + msgs_in_one_page*(page_no - 1);
        }
        /*
         * 编写条件语句
         */        
        sql += msgid!=null ? " and msgid='" + msgid + "' ":"";
        sql += username != null?" and username='" + username + "' ":"";
        sql += title!=null ? " and title='" + title + "' ":"";
        sql += msgcontent!=null ? " and msgcontent='" + msgcontent + "' ":"";
        sql += sendto!=null ? " and sendto='" + sendto + "' ":"";
        sql += state!=null ? " and state=" + state + " ":"";
        sql += msg_create_date!=null ? " and msg_create_date='" + sdf.format(msg_create_date) + "' ":"";    
        
        /*
         * 返回结果
         */
        List <BBSMessage>list = null;        
        openConnection();
        list = new ArrayList<BBSMessage>();
        try {
            ps = con.prepareStatement(sql);
            rs = ps.executeQuery();
            while(rs.next()){
                BBSMessage bms = new BBSMessage();
                bms.setMsgid(rs.getString("msgid"));
                bms.setTitle(rs.getString("title"));
                bms.setContent(rs.getString("msgcontent"));
                bms.setSendto(rs.getString("sendto"));
                bms.setState(rs.getInt("state"));
                bms.setDatetime(rs.getDate("msg_create_date"));
                bms.setUsername(rs.getString("username"));
                list.add(bms);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            closeResource();
        }
        return list;
    }

    public int getMsgsCount(String username) {        
        String always_true = " where 1=1 ";
        int count = 0;
        if(username == null){
            username = "";
        }else{
            username = " and username = '" + username + "'";
        }    
        String sql = "select count(*) from msg " + always_true + username;
        
        openConnection();
        try {
            ps = con.prepareStatement(sql);
            rs = ps.executeQuery();
            while(rs.next())
                count = rs.getInt(1);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return count;
    }

}

3.4 BBSMessageBiz

package cn.jbit.demo.biz;

import java.util.List;
import java.util.Map;

import cn.jbit.demo.entity.BBSMessage;

public interface BBSMessageBiz {    
    //查询短信息
    public List<BBSMessage> findMessages(Map<String,Object> elements);
    //更新或删除短信息
    public int doInsertOrUpdateMsg(String operate, Map<String,Object> elements, Map<String,Object> conditions);
}

 3.5 BBSMessageBizImpl

package cn.jbit.demo.biz.impl;
import java.util.List;
import java.util.Map;

import cn.jbit.demo.biz.BBSMessageBiz;
import cn.jbit.demo.dao.BBSMessageDao;
import cn.jbit.demo.dao.impl.BBSMessageDaoImpl;
import cn.jbit.demo.entity.BBSMessage;

public class BBSMessageBizImpl implements BBSMessageBiz {
    private BBSMessageDao bmd = new BBSMessageDaoImpl();
    //更新或删除短信息
    public int doInsertOrUpdateMsg(String operate, Map<String,Object> elements, Map<String,Object> conditions) {        
        return bmd.executeUpdate(operate, elements, conditions);
    }
    //查询短信息
    public List<BBSMessage> findMessages(Map<String,Object> elements) {
        return bmd.getMessagesByPage(elements);
    }    
}

3.6 MsgServlet

package cn.jbit.demo.web;

import java.io.IOException;
import java.sql.Timestamp;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;

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

import cn.jbit.demo.biz.BBSMessageBiz;
import cn.jbit.demo.biz.impl.BBSMessageBizImpl;
import cn.jbit.demo.entity.BBSMessage;

public class MsgServlet extends HttpServlet {    
    private static final long serialVersionUID = 1L;
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        BBSMessageBiz bmb=new BBSMessageBizImpl();
        String action = request.getParameter("action");
        if(action.equals("del")){//删除短信息
            String msgid = request.getParameter("msgid");
             Map<String,Object> conditions = new HashMap<String,Object>();
             conditions.put("msgid", msgid); 
             int isSuccess = bmb.doInsertOrUpdateMsg("delete",new HashMap<String,Object>(),conditions);
             if(isSuccess > 0){
                 request.setAttribute("error", "删除成功！");
                 request.getRequestDispatcher("MsgServlet?action=list").forward(request,response);
             }else{                 
                 request.setAttribute("error", "删除属于非法操作，请确认当前用户权限！");
                 request.getRequestDispatcher("MsgServlet?action=list").forward(request,response);
             }
        }else if(action.equals("send")){//发送短信息
            Random r = new Random();                        
            String msgid = String.valueOf(r.nextInt());        
              String fromUser = (String)request.getSession().getAttribute("loginuser");
              String toUser = request.getParameter("toUser");
              String title = request.getParameter("title");
              String content = request.getParameter("content");
              String state = "0";
              Timestamp ts = new Timestamp((new Date()).getTime());    
              Map <String,Object>map = new HashMap<String,Object>();            
            map.put("msgid", msgid);
            map.put("sendto", toUser);
            map.put("title", title);
            map.put("msgcontent",content);
            map.put("state", state);
            map.put("username", fromUser);
            map.put("msg_create_date", ts);            
            bmb.doInsertOrUpdateMsg("insert",map,null);
            response.sendRedirect("MsgServlet?action=list");
        }else if(action.equals("list")){//显示当前用户的收件箱
            String username = (String)request.getSession().getAttribute("loginuser");    
            Map <String,Object>map = new HashMap<String,Object>();      
            map.put("sendto", username);                
            List<BBSMessage> list = bmb.findMessages(map);
            request.setAttribute("msgs", list);     
            request.getRequestDispatcher("main.jsp").forward(request,response);
        }else if(action.equals("read")){//读取某条短信息
            Map <String,Object>elements = null;
              Map<String,Object> conditions = null;
              String msgid = request.getParameter("msgid");
              String state = request.getParameter("state");              
              if(state.equals("0")){
                  elements = new HashMap<String,Object>();
                  conditions = new HashMap<String,Object>();
                  elements.put("state", "1");          
                  conditions.put("msgid", msgid);
                  bmb.doInsertOrUpdateMsg("update", elements, conditions);
              }
              if(conditions == null){
                conditions = new HashMap<String,Object> ();
                conditions.put("msgid", msgid);
            }
              List<BBSMessage> list = bmb.findMessages(conditions);
              request.setAttribute("msg", list);
              request.getRequestDispatcher("readMsg.jsp").forward(request,response);
        }        
    }
}

四.数据表

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原文地址：https://www.cnblogs.com/qjt970518--/p/6823426.html