开发工具 idea MySql
用户表

1.系统登陆

实体类
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | publicclassUserInfo {     privateInteger userCode;     privateString userName;     privateString userPwd;     privateDate lastLoginTime;     privatebooleanisUse;     //alt+insert    publicInteger getUserCode() {        returnuserCode;    }    publicvoidsetUserCode(Integer userCode) {        this.userCode = userCode;    }    publicString getUserName() {        returnuserName;    }    publicvoidsetUserName(String userName) {        this.userName = userName;    }    publicString getUserPwd() {        returnuserPwd;    }    publicvoidsetUserPwd(String userPwd) {        this.userPwd = userPwd;    }    publicDate getLastLoginTime() {        returnlastLoginTime;    }    publicvoidsetLastLoginTime(Date lastLoginTime) {        this.lastLoginTime = lastLoginTime;    }    publicbooleanisUse() {        returnisUse;    }    publicvoidsetUse(booleanuse) {        isUse = use;    }} | 
BaseDao
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 | packagecn.blog.dao;importjava.sql.Connection;importjava.sql.DriverManager;importjava.sql.PreparedStatement;importjava.sql.ResultSet;importjava.sql.SQLException;/** * 数据访问工具类 * @version 1.1 * @author happy * */publicclassBaseDao {    // 01. 基础内容的准备    privatestaticfinalString driver="com.mysql.jdbc.Driver";    privatestaticfinalString url="jdbc:mysql:///blog";    privatestaticfinalString username="root";    privatestaticfinalString pwd="root";    //02, 接口对象的准备    Connection con=null;    PreparedStatement ps=null;    publicResultSet rs=null;    /**     * 01.写一个用户获取到一个连接对象的方法,方法的返回值是Connection类型     * @return   连接对象     * @throws Exception     */    publicConnection getConnection() throwsException{        Class.forName(driver);        //什么条件下,构建connection对象        if(con==null||con.isClosed()) {            con=DriverManager.getConnection(url, username, pwd);        }        //同志们碰到一个        returncon;    }    /**     * 执行查询操作  目的:返回一个读取器     * @param sql  sql语句     * @param objs  参数列表     * @return     读取器对象     * @throws Exception     */    publicResultSet  executeQuery(String sql,Object... objs) throwsException{        con=getConnection();        ps = con.prepareStatement(sql);        for(inti = 0; i < objs.length; i++) {            ps.setObject(i+1, objs[i]);        }        rs= ps.executeQuery();        returnrs;    }    /**     * 执行增删该操作     * @param sql  sql语句     * @param objs  参数列表     * @return     受影响行数     * @throws Exception     */    publicintexecuteUpdate(String sql,Object... objs) throwsException{        con=getConnection();        ps = con.prepareStatement(sql);        for(inti = 0; i < objs.length; i++) {            ps.setObject(i+1, objs[i]);        }        intcount = ps.executeUpdate();        returncount;    }    /**     * 回收连接资源     * @throws Exception     */    publicvoidcloseAll() throwsException{        //倒着回收        if(rs!=null){            rs.close();        }        if(ps!=null) {            ps.close();        }        if(con!=null){            con.close();        }    }} | 
dao层impl实现
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | packagecn.blog.dao.iimpl;importcn.blog.dao.BaseDao;importcn.blog.dao.IUserInfoDAO;importcn.blog.entity.UserInfo;importorg.junit.Test;importjava.sql.ResultSet;/** * Created by Happy on 2017-06-30. */publicclassUserInfoDAOImpl extendsBaseDao implementsIUserInfoDAO {    @Test   publicvoidtestIsLogin(){       UserInfo info=newUserInfo();       info.setUserCode(11);       info.setUserPwd("123");       try{           booleanflag = isLogin(info);           System.out.println(flag);       } catch(Exception e) {           e.printStackTrace();       }   }    publicbooleanisLogin(UserInfo info) throwsException {        booleanflag=false;        //根据用户名和密码查看复合条件的记录有几条》》》》》》》》》》》》》》        String  sql="select count(1) as UserCode from userInfo where UserCode=? and UserPwd=?";        Object[] paras={info.getUserCode(),info.getUserPwd()};        ResultSet rs = executeQuery(sql, paras);        if(rs.next()){            if(rs.getInt("UserCode")>0){                flag=true;            }        }        returnflag;    }} | 
selvlet层
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | packagecn.blog.servlet;importcn.blog.dao.IUserInfoDAO;importcn.blog.dao.iimpl.UserInfoDAOImpl;importcn.blog.entity.UserInfo;importjavax.servlet.ServletException;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjava.io.IOException;/** * Created by Happy on 2017-06-30. */publicclassUserInfoServlet extendsHttpServlet {    protectedvoiddoPost(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException {        //write code here please ,oK?        //使用dao实现类        IUserInfoDAO dao=newUserInfoDAOImpl();        String userCode=request.getParameter("userCode");        String userPwd=request.getParameter("userPwd");        UserInfo info=newUserInfo();        System.out.println(userCode+"===================");        info.setUserCode(Integer.parseInt(userCode));        info.setUserPwd(userPwd);        try{            booleanflag = dao.isLogin(info);            if(flag){                request.getRequestDispatcher("/BlogHtTemplate-master/html/main.html").forward(request,response);            }else{                response.sendRedirect("/BlogHtTemplate-master/html/index.html");            }        } catch(Exception e) {            e.printStackTrace();        }        //  dao.isLogin();        //跳转    }    protectedvoiddoGet(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException {        doPost(request,response);    }} | 
实现效果

开发工具 idea MySql
用户表

1.系统登陆

实体类
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | publicclassUserInfo {     privateInteger userCode;     privateString userName;     privateString userPwd;     privateDate lastLoginTime;     privatebooleanisUse;     //alt+insert    publicInteger getUserCode() {        returnuserCode;    }    publicvoidsetUserCode(Integer userCode) {        this.userCode = userCode;    }    publicString getUserName() {        returnuserName;    }    publicvoidsetUserName(String userName) {        this.userName = userName;    }    publicString getUserPwd() {        returnuserPwd;    }    publicvoidsetUserPwd(String userPwd) {        this.userPwd = userPwd;    }    publicDate getLastLoginTime() {        returnlastLoginTime;    }    publicvoidsetLastLoginTime(Date lastLoginTime) {        this.lastLoginTime = lastLoginTime;    }    publicbooleanisUse() {        returnisUse;    }    publicvoidsetUse(booleanuse) {        isUse = use;    }} | 
BaseDao
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 | packagecn.blog.dao;importjava.sql.Connection;importjava.sql.DriverManager;importjava.sql.PreparedStatement;importjava.sql.ResultSet;importjava.sql.SQLException;/** * 数据访问工具类 * @version 1.1 * @author happy * */publicclassBaseDao {    // 01. 基础内容的准备    privatestaticfinalString driver="com.mysql.jdbc.Driver";    privatestaticfinalString url="jdbc:mysql:///wk";    privatestaticfinalString username="root";    privatestaticfinalString pwd="";    //02, 接口对象的准备    Connection con=null;    PreparedStatement ps=null;    publicResultSet rs=null;    /**     * 01.写一个用户获取到一个连接对象的方法,方法的返回值是Connection类型     * @return   连接对象     * @throws Exception     */    publicConnection getConnection() throwsException{        Class.forName(driver);        //什么条件下,构建connection对象        if(con==null||con.isClosed()) {            con=DriverManager.getConnection(url, username, pwd);        }        //同志们碰到一个        returncon;    }    /**     * 执行查询操作  目的:返回一个读取器     * @param sql  sql语句     * @param objs  参数列表     * @return     读取器对象     * @throws Exception     */    publicResultSet  executeQuery(String sql,Object... objs) throwsException{        con=getConnection();        ps = con.prepareStatement(sql);        for(inti = 0; i < objs.length; i++) {            ps.setObject(i+1, objs[i]);        }        rs= ps.executeQuery();        returnrs;    }    /**     * 执行增删该操作     * @param sql  sql语句     * @param objs  参数列表     * @return     受影响行数     * @throws Exception     */    publicintexecuteUpdate(String sql,Object... objs) throwsException{        con=getConnection();        ps = con.prepareStatement(sql);        for(inti = 0; i < objs.length; i++) {            ps.setObject(i+1, objs[i]);        }        intcount = ps.executeUpdate();        returncount;    }    /**     * 回收连接资源     * @throws Exception     */    publicvoidcloseAll() throwsException{        //倒着回收        if(rs!=null){            rs.close();        }        if(ps!=null) {            ps.close();        }        if(con!=null){            con.close();        }    }} | 
dao层impl实现
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | packagecn.blog.dao.iimpl;importcn.blog.dao.BaseDao;importcn.blog.dao.IUserInfoDAO;importcn.blog.entity.UserInfo;importorg.junit.Test;importjava.sql.ResultSet;/** * Created by Happy on 2017-06-30. */publicclassUserInfoDAOImpl extendsBaseDao implementsIUserInfoDAO {    @Test   publicvoidtestIsLogin(){       UserInfo info=newUserInfo();       info.setUserCode(11);       info.setUserPwd("123");       try{           booleanflag = isLogin(info);           System.out.println(flag);       } catch(Exception e) {           e.printStackTrace();       }   }    publicbooleanisLogin(UserInfo info) throwsException {        booleanflag=false;        //根据用户名和密码查看复合条件的记录有几条》》》》》》》》》》》》》》        String  sql="select count(1) as UserCode from userInfo where UserCode=? and UserPwd=?";        Object[] paras={info.getUserCode(),info.getUserPwd()};        ResultSet rs = executeQuery(sql, paras);        if(rs.next()){            if(rs.getInt("UserCode")>0){                flag=true;            }        }        returnflag;    }} | 
selvlet层
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | packagecn.blog.servlet;importcn.blog.dao.IUserInfoDAO;importcn.blog.dao.iimpl.UserInfoDAOImpl;importcn.blog.entity.UserInfo;importjavax.servlet.ServletException;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjava.io.IOException;/** * Created by Happy on 2017-06-30. */publicclassUserInfoServlet extendsHttpServlet {    protectedvoiddoPost(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException {        //write code here please ,oK?        //使用dao实现类        IUserInfoDAO dao=newUserInfoDAOImpl();        String userCode=request.getParameter("userCode");        String userPwd=request.getParameter("userPwd");        UserInfo info=newUserInfo();        System.out.println(userCode+"===================");        info.setUserCode(Integer.parseInt(userCode));        info.setUserPwd(userPwd);        try{            booleanflag = dao.isLogin(info);            if(flag){                request.getRequestDispatcher("/BlogHtTemplate-master/html/main.html").forward(request,response);            }else{                response.sendRedirect("/BlogHtTemplate-master/html/index.html");            }        } catch(Exception e) {            e.printStackTrace();        }        //  dao.isLogin();        //跳转    }    protectedvoiddoGet(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException {        doPost(request,response);    }} | 
实现效果

原文:http://www.cnblogs.com/hfddz/p/7105088.html