Java-Java基础13之JSP与MVC模式开发用户管理系统

主要内容有：使用JSP+JavaBean模式与MVC模式开发用户管理系统。

Jsp内置对象
文件结构

1.out //向客户端输出数据，字节流
out.println("");

2.request //接收客户端的http请求 <----->servlet中的HttpServletRequest
getParameter(String name); //name表表单的参数名
getParameterValues(String name); //得到参数值集，使用String []
setAttribute(String name,Object obj); //设置名字为name的obj,值为obj
getAttribute(String name); //返回由name指定的属性值，如果不存在就返回null;
getCookie();

3.response //封装jsp的产生的回应
addCookie(Cookie cookie);
sendRedirect("./welcome.jsp");

4.session //用于保存用户的信息，跟踪用户的行为
setAttribute(String name,Object obj);
getAttribute(String name);

5.applicattion //多个用户共享该对象，可以做计数器
6.pageContext //代表jsp页面的上下文
7.exception //代表运行的一个异常
getMessage();

8.page //代表jsp这个实例本身(使用比较少)
9.config //代表jsp对应的servlet的配置，可以得到web.xml中的参数

//===========================================================================
//------------session技术--------------
1.得到session
servlet中：HttpSession hs=request.getSession(true);
jsp中：session是一个内置对象，可以直接使用

2.向session添加属性
servlet中：hs.setAttribute(String name,Object val);
jsp中：session.setAttribute(String name,Object o);

3.从session得到某个属性//(getAttribute得到的属性是Object类型，要注意转换类型)
servlet中：hs.getAttribute(String name);
jsp中：session.getAttribute(String name);

4.从session删除掉某个属性
servlet中：hs.removeAttribute(String name);
jsp中：session.removeAttribute(String name);

5.指定session发吊时的存活时间//(这设置成20秒，默认是30分钟)
servlet中：hs.setMaxInactive(20);
jsp中：session.setMaxInactive(20);

6.session的特点：
//1.session是被某个浏览器独占的空间，
//2.当某个浏览器访问网站时，服务器会给浏览器分配一个唯一的session id,以此区分不同客户端
//3.由于session的各个属性要占用服务器内存，因此要迫不得以，才使用，如下情况用：
//1.保存用户信息
//2.保存购物车 等

Jsp测试案例(MyHello.jsp)

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'MyHello.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>
Hello,维唯为为 <br>
</body>
</html>

Jsp+javaBean(java文件)模式开发用户管理系统

1. jsp+java_class模式下的用户管理系统模型图
jsp+java

2.登录界面_UserManagerSys/src/webRoot/login.jsp

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'login.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 bgcolor="pink">
<center>
    用户登录 <br>
    <hr>
    <form action="loginCl.jsp" method="post">
        用户名：<input type="text" name="username"/><br>
        密&nbsp;&nbsp;码：<input type="password" name="passwd"/><br>
        <input type="submit" value="登录"/>
        <input type="reset" value="重置"/>
    </form>
</center>
</body>
</html>

3.登录处理界面_UserManagerSys/src/webRoot/loginCl.jsp

<%@ page language="java" import="java.util.*,java.sql.*,user.model.*" pageEncoding="gb2312"%>
<%
        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 'loginCl.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>
<%
        //接收用户名和密码，完成对用户的验证
        String u=request.getParameter("username");
        String p=request.getParameter("passwd");
//到数据库中去验证用户
        //调用UserBeanCl的方法，完成对用户的验证
        UserBeanCl ubc=new UserBeanCl();
        if(ubc.checkUser(u,p))
        {
        response.sendRedirect("wel.jsp?username="+u);
        }else
        {
        response.sendRedirect("login.jsp?errNo=1");
        }
        %>
</body>
</html>

4.欢迎界面_UserManagerSys/src/webRoot/wel.jsp

<%@ page language="java" import="java.util.*,java.sql.*,user.model.*" pageEncoding="gb2312"%>
<%
    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 'wel.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 bgcolor="pink">
<%
    String u=request.getParameter("username");
%>
登录成功！维唯为为恭喜你！<%=u %><br>
<a href="login.jsp">返回重新登录</a>
<hr>
<center>
    <h1>用户信息列表</h1>
    <%
        //定义分页用到的变量
        int pageNow=1;
        //接收用户希望显示的页数(pageNow)
        String s_pageNow=request.getParameter("pageNow");
        if(s_pageNow!=null)
        {
            //接收到pageNow
            pageNow=Integer.parseInt(s_pageNow);
        }
        //调用UserBeanCl的方法(创建一个UserBeanCl的实例，然后调用它的某个方法)，完成分布显示
        UserBeanCl ubc=new UserBeanCl();
        ArrayList al=ubc.getUserByPage(pageNow);
        //显示
    %>
    <table border="1">
        <tr><td>用户id</td><td>用户名</td><td>密码</td><td>邮箱</td><td>级别</td></tr>
        <%
            for(int i=0;i<al.size();i++)
            {    //从al中取出UserBean
                UserBean ub=(UserBean)al.get(i);
        %>
        <tr><td><%=ub.getUserId() %></td><td><%=ub.getUsername() %></td>
            <td><%=ub.getPasswd() %></td><td><%=ub.getEmail() %></td>
            <td><%=ub.getGrade() %></td></tr>
        <%
            }
        %>
    </table>
    <%
        int pageCount=ubc.getPageCount();
        int pageSize=ubc.getPageSize();
        //首页
        out.println("<a href=wel.jsp?pageNow=1&username="+u+">首页</a>");
        //上一页
        if(pageNow!=1)
        {
            out.println("<a href=wel.jsp?pageNow="+(pageNow-1)+"&username="+u+">上一页</a>");
        }
        //显示页面链接
        for(int i=pageNow;i<pageNow+pageSize&&i<=pageCount;i++)
        {
            out.println("<a href=wel.jsp?pageNow="+i+"&username="+u+">["+i+"]</a>");
        }
        //下一页
        if(pageNow!=pageCount)
        {
            out.println("<a href=wel.jsp?pageNow="+(pageNow+1)+"&username="+u+">下一页</a>");
        }
        //尾页
        out.println("<a href=wel.jsp?pageNow="+pageCount+"&username="+u+">尾页</a>");
    %>
</center>
</body>
</html>

5.model层_UserManagerSys/src/user.model/UserBeanCl.java

/**
 * 这是一个处理类，有些人把它叫做BO,主要是封装对user表的各种操作，(主要
 * 是增，删，修，查...)
 */
package user.model;
import java.sql.*;
import java.util.*;
public class UserBeanCl {
    private Statement sm=null;
    private ResultSet rs=null;
    private Connection ct=null;
    private int pageSize=5;
    public int getPageSize() {
        return pageSize;
    }
    private int rowCount=0; //行数
    private int pageCount=0;//页数
    //验证用户是否存在
    public boolean checkUser(String u,String p)
    {
        boolean b=false;
        try {
            //到数据库去验证
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //4.查询
            ResultSet rs=sm.executeQuery("select passwd from users where username='"+u+"'");
            //验证
            if(rs.next())
            {
                //到此说明输入的用户名存在
                if(rs.getString(1).equals(p))
                {
                    b=true;
                    //合法，跳转wel.jsp
                    //如何将loginCl.jsp得到的数据传到下一个页面
                    //1.cookie 2.session 3.response.sendRedirect
                    //response.sendRedirect("wel.jsp?user="+u);//将用户发送过去
                }else
                {
                    //密码错误
                }
            }else
            {
                //用户名错误
                //不合法，跳转到login.jsp
                //response.sendRedirect("login.jsp?errNo=1");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            //关闭打开的各种资源
            this.close();
        }
        return b;
    }
    /**
     * @author luowei
     * @return 返回分页的总页数
     */
    public int getPageCount()
    {
        try {
            //得到连接
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //4.查询
            ResultSet rs=sm.executeQuery("select count(*) from users");
            if(rs.next())//将游标从第0条记录移到第1条记录，并判断是否为空
            {
                rowCount=rs.getInt(1);
            }
            //计算
            if(rowCount%pageSize==0)
            {
                pageCount=rowCount/pageSize;
            }else
            {
                pageCount=rowCount/pageSize+1;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally
        {
            this.close();
        }
        return pageCount;
    }
    /**@得到用户需要显示的用户信息(分页)
     * @author luowei
     * @param pageNow:当前页
     * @return
     */
    public ArrayList getUserByPage(int pageNow)
    {
        ArrayList al=new ArrayList();
        try {
            //得到连接
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //查询出需要显示的记录
            rs=sm.executeQuery("select * from users limit "+(pageSize*(pageNow-1))+","+pageSize);
            //开始将rs封装到ArrayList
            while(rs.next())
            {
                UserBean ub=new UserBean();
                ub.setUserId(rs.getInt(1));
                ub.setUsername(rs.getString(2));
                ub.setPasswd(rs.getString(3));
                ub.setEmail(rs.getString(4));
                ub.setGrade(rs.getInt(5));
                al.add(ub);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            this.close();
        }
        return al;
    }
    /**@author luowei
     * @see关闭资源
     * @return null
     *
     */
    public void close()
    {
        try {
            if(rs!=null)
            {
                rs.close();
                rs=null;
            }
            if(sm!=null)
            {
                sm.close();
                sm=null;
            }
            if(ct!=null)
            {
                ct.close();
                ct=null;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

6.model层_UserManagerSys/src/user.model/UserBean.java

/**
 * 这是一个javabean,对应user表，代表数据
 * 他的一个实例(对象),对应users的一条
 */
package user.model;
public class UserBean {
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPasswd() {
        return passwd;
    }
    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public int getGrade() {
        return grade;
    }
    public void setGrade(int grade) {
        this.grade = grade;
    }
    private int userId;
    private String username;
    private String passwd;
    private String email;
    private int grade;
}

5.model层_UserManagerSys/src/user.model/ConnDB.java

/**
 * 得到数据库的连接
 */
package user.model;
import java.sql.*;
public class ConnDB {
    private Connection ct=null;
    public Connection getConn()
    {
        try {
            //1.加载驱动
            Class.forName("org.gjt.mm.mysql.Driver").newInstance();
            //Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
            //2.得到连接
            ct=DriverManager.getConnection("jdbc:mysql://localhost:3306/test_user","root","root");
            //ct=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databaseName=testusr","sa","luowei");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ct;
    }
}

MVC模式开发用户管理系统

1. MVC模介绍
MVC模型图
MVC模型图

mvc用户管理系统模型图
mvc用户管理系统模型图

2.向数据库添加用户表

create database test_user;
use test_user;
create table users(
  useId int primary key AUTO_INCREMENT,#用户id号
        username varchar(20),
  passwd varchar(20),
  email varchar(30),
  grade int #用户的级别
);
insert into users values(null,"admin","admin","admin@sohu.com","1");
insert into users values(null,"luowei","luowei505050","luowei@163.com","1");
insert into users values(null,"test1","test1","test1@sina.com","5");
insert into users values(null,"test2","test2","test2@sina.com","2");
insert into users values(null,"test3","test3","test3@sina.com","5");
insert into users values(null,"test4","test4","test4@sina.com","6");
insert into users values(null,"test5","test5","test5@sina.com","6");
insert into users values(null,"test6","test6","test6@sina.com","7");
insert into users values(null,"test7","test7","test7@sina.com","7");
insert into users values(null,"test8","test8","test8@sina.com","8");
insert into users values(null,"test9","test9","test9@sina.com","8");
insert into users values(null,"test10","test10","test10@sina.com","9");
insert into users values(null,"test11","test11","test11@sina.com","3");
insert into users values(null,"test12","test12","test12@sina.com","4");
select * from users;
insert into users(username,passwd,email,grade) select username,passwd,email,grade from users;
select * from users where username=admin and passwd=admin;
#添加新列
alter table users add myPic varchar(30);
#修改数据
update users set myPic='luowei.gif' where userName='luowei';
update users set myPic='admin.gif' where userName='admin';
update users set myPic='test1.gif' where userName='test1';
#drop table users;
#--------------------------------------------------------------------
CREATE TABLE person (
  id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT,
  name CHAR(60) NOT NULL,
  PRIMARY KEY (id)
);
CREATE TABLE shirt (
  id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT,
  style ENUM('t-shirt', 'polo', 'dress') NOT NULL,
  color ENUM('red', 'blue', 'orange', 'white', 'black') NOT NULL,
owner SMALLINT UNSIGNED NOT NULL REFERENCES person(id),
PRIMARY KEY (id)
);
INSERT INTO person VALUES (NULL, 'Antonio Paz');
SELECT @last := LAST_INSERT_ID();
INSERT INTO shirt VALUES
  (NULL, 'polo', 'blue', @last),
  (NULL, 'dress', 'white', @last),
  (NULL, 't-shirt', 'blue', @last);
INSERT INTO person VALUES (NULL, 'Lilliana Angelovska');
SELECT @last := LAST_INSERT_ID();
INSERT INTO shirt VALUES
  (NULL, 'dress', 'orange', @last),
  (NULL, 'polo', 'red', @last),
  (NULL, 'dress', 'blue', @last),
  (NULL, 't-shirt', 'white', @last);
SELECT * FROM person;
SELECT * FROM shirt;
SELECT s.* FROM person p, shirt s
WHERE p.name LIKE 'Lilliana%'
      AND s.owner = p.id
      AND s.color <> 'white';
#----------------------------------------------------------
select * from users order by useId limit 5;

界面层(View层)

登录界面_UserManageSys2/WebRoot/WEB-INF/login.jsp
登录界面

<!-- 登录界面 -->
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'login.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 bgcolor="ff9900">
<center>
    <%
        String errNo=request.getParameter("errNo");
        if(errNo!=null)
        {
            if(errNo.equals("1"))
            {
                out.println("<font color=red size=7>登录错误，请输入正确的用户名和密码！</font><br>");
            }
        }
    %>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    用户登录 <br>
    <form action="LoginClServlet" method="post">
        用户名：<input type="text" name="username"/><br>
        密&nbsp;&nbsp;码：<input type="password" name="passwd"/><br>
        <input type="submit" value="登录"/>
        <input type="reset" value="重置"/>
    </form>
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

登录处理界面_UserManageSys2/WebRoot/WEB-INF/loginCl.jsp

<%@ page language="java" import="java.util.*,java.sql.*,user.model.*" pageEncoding="gb2312"%>
<%
    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 'loginCl.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>
<%
    //接收用户名和密码，完成对用户的验证
    String u=request.getParameter("username");
    String p=request.getParameter("passwd");
//到数据库中去验证用户
    //调用UserBeanCl的方法，完成对用户的验证
    UserBeanCl ubc=new UserBeanCl();
    if(ubc.checkUser(u,p))
    {
        response.sendRedirect("wel.jsp?username="+u);
    }else
    {
        response.sendRedirect("login.jsp?errNo=1");
    }
%>
</body>
</html>

主界面_UserManageSys2/WebRoot/WEB-INF/Main.jsp
主界面

<!--主界面 -->
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'Main.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 bgcolor="ff9900">
<%
    String u=request.getParameter("username");
    //System.out.println("Main.jsp得到的username="+u);
%>
<center>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    <h1>请选择操作</h1>
    <a href="UserClServlet?pageNow=1&flag=fenye&username=<%=u %>" >管理用户</a><br/>
    <!-- flag标志告诉控制器，进行分页 -->
    <!-- 注意这里变量<%=u %>要放在双引号里边，直接赋给username -->
    <a href="addUser.jsp?username=<%=u %>">添加用户</a><br/>
    <a href="#">查找用户</a><br/>
    <a href="#">注销用户</a><br/>
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

欢迎界面_UserManageSys2/WebRoot/WEB-INF/wel.jsp
欢迎界面

<!--欢迎界面 -->
<%@ page language="java" import="java.util.*,java.sql.*,user.model.*" pageEncoding="gb2312"%>
<%
    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 'wel.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">
    -->
    <script type="text/javascript">
        <!--
        function msg()
        {
            return window.confirm("你确认要删除吗？");
        }
        -->
    </script>
</head>
<body bgcolor="ff9900">
<%
    String u=request.getParameter("username");
    //System.out.println("UserClServlet得到的username="+u);
    //u=new String(u.getBytes("gb2312"),"iso-8859-1"); //转码
    //防止用户非法登录
    String userName=(String)session.getAttribute("myName");
    //如果用户没有登录
    if(userName==null)
    {
        //返回登录界面
        response.sendRedirect("login.jsp?errNo=1");
        return ;
    }
%>
登录成功！维唯为为恭喜你！<%=u %><br/>
session得到的用户名为：<%=userName %><br/>
<a href="login.jsp">返回重新登录</a>&nbsp;&nbsp;
<a href="Main.jsp?username=<%=u %>">返回主界面</a>
<hr>
<center>
    <h1>用户信息列表</h1>
    <%
        //调用UserBeanCl的方法(创建一个UserBeanCl的实例，然后调用它的某个方法)，完成分布显示
        //UserBeanCl ubc=new UserBeanCl();
        //ArrayList al=ubc.getUserByPage(pageNow);
        //要显示的用户信息从request中取
        ArrayList al=(ArrayList)request.getAttribute("result");
        //显示
    %>
    <%
        //得到pageCount
        String s_pageCount=(String)request.getAttribute("pageCount");
        int pageCount=Integer.parseInt(s_pageCount);
        String s_pageSize=(String)request.getAttribute("pageSize");
        int pageSize=Integer.parseInt(s_pageSize);
        String s_pageNow=(String)request.getAttribute("pageNow");
        int pageNow=Integer.parseInt(s_pageNow);
    %>
    <table border="1">
        <tr bgcolor="pink"><td>用户id</td><td>用户名</td><td>密码</td>
            <td>邮箱</td><td>级别</td><td>修改用户</td><td>删除用户</td></tr>
        <%
            //定义一个颜色数组
            String []color={"silver","pink"};
            for(int i=0;i<al.size();i++)
            {    //从al中取出UserBean
                UserBean ub=(UserBean)al.get(i);
        %>
        <tr bgcolor="<%=color[i%2] %>"><td><%=ub.getUserId() %></td><td><%=ub.getUsername() %></td>
            <td><%=ub.getPasswd() %></td><td><%=ub.getEmail() %></td>
            <td><%=ub.getGrade() %></td>
            <td><a href="updateUser.jsp?username=<%=u%>&pageNow=<%=pageNow %>&userId=<%=ub.getUserId()
                     %>&userName=<%=ub.getUsername() %>&passWd=<%=ub.getPasswd() %>&email=<%=ub.getEmail()
                     %>&grade=<%=ub.getGrade() %>">修改用户</a></td>
            <td><a onclick="return msg()" href="UserClServlet?username=<%=u%>&pageNow=<%=pageNow
                     %>&flag=delUser&userid=<%=ub.getUserId() %>">删除用户</a></td></tr>
        <%
            }
        %>
    </table>
    <%
        //首页
        out.println("<a href=UserClServlet?flag=fenye&pageNow=1&username="+u+">首页</a>"); //转到分页控制器处理
        //上一页
        if(pageNow!=1)
        {
            out.println("<a href=UserClServlet?flag=fenye&pageNow="+(pageNow-1)+"&username="+u+">上一页</a>");
        }
        //显示页面链接
        for(int i=pageNow;i<pageNow+pageSize&&i<=pageCount;i++)
        {
            out.println("<a href=UserClServlet?flag=fenye&pageNow="+i+"&username="+u+">["+i+"]</a>");
        }
        //下一页
        if(pageNow!=pageCount)
        {
            out.println("<a href=UserClServlet?flag=fenye&pageNow="+(pageNow+1)+"&username="+u+">下一页</a>");
        }
        //尾页
        out.println("<a href=UserClServlet?flag=fenye&pageNow="+pageCount+"&username="+u+">尾页</a>");
    %>
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

修改界面_UserManageSys2/WebRoot/WEB-INF/updateUser.jsp
修改界面

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'updateUser.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 bgcolor="ff9900">
<%
    String u=request.getParameter("username");
    String pageNow=request.getParameter("pageNow");
    //String flag=request.getParameter("flag");
    //System.out.println("Main.jsp得到的username="+u);
%>
欢迎您：<%=u %><br>
<a href="Main.jsp?username=<%=u %>">返回主界面</a>
<a href="UserClServlet?username=<%=u %>&UserClServlet=<%=u %>&pageNow=<%=pageNow %>&flag=fenye">返回上一页</a>
<center>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    <h1>修改用户信息</h1>
    <form action="UserClServlet?pageNow=1&flag=updateUser&username=<%=u %>" method="post">
        <table border="1">
            <tr bgcolor="pink"><td>用户Id</td><td><input readonly type="text" name="userId" value="<%=request.getParameter("userId") %>"/></td></tr>
            <tr bgcolor="pink"><td>用户名</td><td><input type="text" name="userName" value="<%=request.getParameter("userName") %>"/></td></tr>
            <tr bgcolor="silver"><td>密码</td><td><input type="text" name="passWd" value="<%=request.getParameter("passWd") %>"/></td></tr>
            <tr bgcolor="pink"><td>电子邮件</td><td><input type="text" name="email" value="<%=request.getParameter("email") %>"/></td></tr>
            <tr bgcolor="silver"><td>级别</td><td><input type="text" name="grade" value="<%=request.getParameter("grade") %>"/></td></tr>
        </table>
        <input type="submit" value="修改信息"/>&nbsp;&nbsp;
    </form>
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

添加用户界面_UserManageSys2/WebRoot/WEB-INF/addUser.jsp
添加用户界面

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'addUser.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 bgcolor="ff9900">
<%
    String u=request.getParameter("username");
    //System.out.println("Main.jsp得到的username="+u);
%>
欢迎您：<%=u %><br>
<a href="Main.jsp?username=<%=u %>">返回主界面</a>
<center>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    <h1>请输入用户信息</h1>
    <form action="UserClServlet?pageNow=1&flag=addUser&username=<%=u %>" method="post">
        <table border="1">
            <tr bgcolor="pink"><td>用户名</td><td><input type="text" name="userName"/></td></tr>
            <tr bgcolor="silver"><td>密码</td><td><input type="text" name="password"/></td></tr>
            <tr bgcolor="pink"><td>电子邮件</td><td><input type="text" name="email"/></td></tr>
            <tr bgcolor="silver"><td>级别</td><td><input type="text" name="grade"/></td></tr>
        </table>
        <input type="submit" value="添加用户"/>&nbsp;&nbsp;
        <input type="reset" value=" 重 置 "/>
    </form>
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

操作成功界面_UserManageSys2/WebRoot/WEB-INF/suc.jsp
操作成功界面

<!-- 登录界面 -->
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'login.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 bgcolor="ff9900">
<center>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    <%
        String u=request.getParameter("username");
        //String pageNow=request.getParameter("pageNow");
        //String flag=request.getParameter("flag");
    %>
    <h1>恭喜你 <%=u %>，操作成功！</h1><br>
    <a href="Main.jsp?username=<%=u %>">返回主界面</a>
    <!--
        <a href="addUser.jsp?username=<%=u %>">返回上一页</a>
        -->
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

操作失败界面_UserManageSys2/WebRoot/WEB-INF/err.jsp
操作失败界面

<!-- 登录界面 -->
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
    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 'login.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 bgcolor="ff9900">
<center>
    <!-- 引入一张图片 -->
    <img src="imgs/1.gif"/>
    <hr>
    <%
        String u=request.getParameter("username");
        //String pageNow=request.getParameter("pageNow");
        //String flag=request.getParameter("flag");
    %>
    <h1>操作不成功！</h1><br>
    <a href="Main.jsp?username=<%=u %>">返回主界面</a>
    <!--
        <a href="addUser.jsp?username=<%=u %>">返回上一页</a>
        -->
    <hr>
    <!-- 引入一张图片 -->
    <img src="imgs/logo.gif"/>
</center>
</body>
</html>

控制器层(controller层)

登录处理_UserManageSys2/ src/user.controller/LoginClServer.java

/**
 * 这是一个控制器，主要完成对用户身份的验证
 * 控制器本身是不会去完成业务逻辑，它主要是去调用模型完成对数据的处理
 */
package user.controller;
import user.model.*;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginClServlet extends HttpServlet {
    /**
     * 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 {
        //得到用户名和密码
        String u=request.getParameter("username");
        //u=new String(u.getBytes("iso-8859-1"),"gb2312");//将用户名转码，解决中文乱码而导致的验证错误
        String p=request.getParameter("passwd");
        System.out.println("username="+u+" password="+p);
        //使用模型(UserBeanCl)，完成对用户的验证
        //1.创建一个UserBeanCl对象
        UserBeanCl ubc=new UserBeanCl();
        //调用方法
        if(ubc.checkUser(u, p))
        {
            //System.out.println("使用了servlet控制器完成验证！");
            //在跳转到wel.jsp页面时，就把要显示的数据给wel.jsp准备好
            ArrayList al=ubc.getUserByPage(1);
            int pageCount=ubc.getPageCount();
            int pageSize=ubc.getPageSize();
            //将al,pageCount,pageNow,pageSize放入request当中
            request.setAttribute("result", al);
            request.setAttribute("pageCount", pageCount+"");
            //因为第二个参数是对象，用int直接传递，后边使用时不好处理，所以把它转成String
            request.setAttribute("pageSize", pageSize+"");
            request.setAttribute("pageNow", "1");
            //合法
            //response.sendRedirect("wel.jsp?username="+u);
            //因为sendRedirect方法效率不高，所以一般多是用转发的方法
            //将用户名放入session,以备后用
            request.getSession().setAttribute("myName", u);
            //这种方法的效率高，同时保证了request中的原有对象还可以在下一面页使用
            //所以就不需要加(?username="+u)了
            request.getRequestDispatcher("Main.jsp").forward(request, response);
        }else
        {
            //不合法
            request.getRequestDispatcher("login.jsp").forward(request, response);
            System.out.println("LoginClServlet验证不合法");
        }
    }
    /**
     * 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 {
        //合二为一
        this.doGet(request, response);
    }
}

处理用户的服务_UserManageSys2/ src/user.controller/UserClServer.java

/**
 * 这个控制器，将处理用户的分页显示，用户的删除，修改，添加
 */
package user.controller;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import user.model.*;
public class UserClServlet extends HttpServlet {
    /**
     * 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 {
        //获得标志
        String flag=request.getParameter("flag");
        if(flag.equals("fenye")) //如果是分页
        {
            try {
                //得到用户希望显示的信息
                int pageNow=Integer.parseInt(request.getParameter("pageNow"));
                String u=request.getParameter("username");
                System.out.println("UserClServlet得到的username="+u);
                //调用UserBeanCl
                UserBeanCl ubc=new UserBeanCl();
                //在跳转到wel.jsp页面时，就把要显示的数据给wel.jsp准备好
                ArrayList al=ubc.getUserByPage(pageNow); //经UserBeanCl处理后，获得当前页的数据
                int pageCount=ubc.getPageCount();
                int pageSize=ubc.getPageSize();
                //将al,pageCount,pageNow,pageSize放入request当中
                request.setAttribute("result", al);
                request.setAttribute("pageCount", pageCount+"");
                //因为第二个参数是对象，用int直接传递，后边使用时不好处理，所以把它转成String
                request.setAttribute("pageSize", pageSize+"");
                request.setAttribute("username", u);
                request.setAttribute("pageNow", pageNow+"");
                //重新跳转回wel.jsp
                request.getRequestDispatcher("wel.jsp").forward(request, response);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }else if(flag.equals("delUser")) //如果是删除
        {
            //完成删除
            //1.得到要删除的用户的id
            String userId=request.getParameter("userid");
            //创建UserBeanCl
            UserBeanCl ubc=new UserBeanCl();
            if(ubc.delUserById(userId))
            {
                //删除成功
                request.getRequestDispatcher("suc.jsp").forward(request, response);
            }else
            {
                //删除失败
                request.getRequestDispatcher("err.jsp").forward(request, response);
            }
        }else if(flag.equals("addUser")) //如果是添加
        {
            //完成添加用户
            //1.得到用户输入的信息
            String name=request.getParameter("userName");
            String passwd=request.getParameter("password");
            String email=request.getParameter("email");
            String grade=request.getParameter("grade");
            //创建UserBeanCl
            UserBeanCl ubc=new UserBeanCl();
            if(ubc.addUser(name, passwd, email, grade))
            {
                //添加成功
                request.getRequestDispatcher("suc.jsp").forward(request, response);
            }else
            {
                //添加失败
                request.getRequestDispatcher("err.jsp").forward(request, response);
            }
        }else if(flag.equals("updateUser")) //如果是修改
        {
            //完成添加用户
            //1.得到用户输入的信息
            String id=request.getParameter("userId");
            String name=request.getParameter("userName");
            String passwd=request.getParameter("passWd");
            String email=request.getParameter("email");
            String grade=request.getParameter("grade");
            //创建UserBeanCl
            UserBeanCl ubc=new UserBeanCl();
            if(ubc.updateUser(id,name, passwd, email, grade))
            {
                //修改成功
                request.getRequestDispatcher("suc.jsp").forward(request, response);
            }else
            {
                //修改失败
                request.getRequestDispatcher("err.jsp").forward(request, response);
            }
        }
    }
    /**
     * 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 {
        this.doGet(request, response);
    }
}

业务逻辑层(model层)

Users表_UserManageSys2/src/user.model/UserBean.java

/**
 * 这是一个javabean,对应user表，代表数据
 * 他的一个实例(对象),对应users的一条
 */
package user.model;
public class UserBean {
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPasswd() {
        return passwd;
    }
    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public int getGrade() {
        return grade;
    }
    public void setGrade(int grade) {
        this.grade = grade;
    }
    private int userId;
    private String username;
    private String passwd;
    private String email;
    private int grade;
}

表处理_UserManageSys2/ src/user.model/UserBeanCl.java

/**
 * 这是一个处理类，有些人把它叫做BO,主要是封装对user表的各种操作，(主要
 * 是增，删，修，查...)
 */
package user.model;
import java.io.UnsupportedEncodingException;
import java.sql.*;
import java.util.*;
public class UserBeanCl {
    private Statement sm=null;
    private ResultSet rs=null;
    private Connection ct=null;
    private int pageSize=5;
    public int getPageSize() {
        return pageSize;
    }
    private int rowCount=0; //行数
    private int pageCount=0;//页数
    /**
     * 验证用户是否存在
     * @param u
     * @param p
     * @return
     */
    public boolean checkUser(String u,String p)
    {
        boolean b=false;
        try {
            //到数据库去验证
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //4.查询
            ResultSet rs=sm.executeQuery("select passwd from users where username='"+u+"'");
            //验证
            if(rs.next())
            {
                //到此说明输入的用户名存在
                if(rs.getString(1).equals(p))
                {
                    b=true;
                    //合法，跳转wel.jsp
                    //如何将loginCl.jsp得到的数据传到下一个页面
                    //1.cookie 2.session 3.response.sendRedirect
                    //response.sendRedirect("wel.jsp?user="+u);//将用户发送过去
                }else
                {
                    //密码错误
                }
            }else
            {
                //用户名错误
                //不合法，跳转到login.jsp
                //response.sendRedirect("login.jsp?errNo=1");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            //关闭打开的各种资源
            this.close();
        }
        return b;
    }
    /**添加用户
     * @author luowei
     * @param name:用户名
     * @param passwd:密码
     * @param email:电子邮件
     * @param grade:级别
     * @return boolean
     */
    public boolean addUser(String name,String passwd,String email,String grade)
    {
        boolean b=false;
        try {
            //得到连接
            ct=new ConnDB().getConn();
            sm=ct.createStatement();
            //执行
            int a=sm.executeUpdate("insert into users(username,passwd,email,grade) "
                    +"values('"+name+"','"+passwd+"','"+email+"','"+grade+"') ");
            if(a==1) //1表示是否是成功的添加了1条记录
            {
                //添加成功
                b=true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return b;
    }
    /**
     * 修改用户
     * @author luowei
     *
     */
    public boolean updateUser(String id,String name,String passwd,String email,String grade)
    {
        boolean b=false;
        try {
            //得到连接
            ct=new ConnDB().getConn();
            sm=ct.createStatement();
            //执行
            int a=sm.executeUpdate("update users set username='"+name+"',passwd='"+passwd+"',email='"
                    +email+"',grade='"+grade+"' where useId='"+id+"'");
            if(a==1) //1表示是否是成功的修改了1条记录
            {
                //修改成功
                b=true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return b;
    }
    /**删除用户
     * @author luowei
     */
    public boolean delUserById(String id)
    {
        boolean b=false;
        //int Id=Integer.parseInt(id);
        try {
            //得到连接
            ct=new ConnDB().getConn();
            sm=ct.createStatement();
            //执行
            int a=sm.executeUpdate("delete from users where useId='"+id+"'");
            if(a==1)
            {
                //删除成功
                b=true;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            this.close();
        }
        return b;
    }
    /**
     * @author luowei
     * @return 返回分页的总页数
     */
    public int getPageCount()
    {
        try {
            //得到连接
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //4.查询
            ResultSet rs=sm.executeQuery("select count(*) from users");
            if(rs.next())//将游标从第0条记录移到第1条记录，并判断是否为空
            {
                rowCount=rs.getInt(1);
            }
            //计算
            if(rowCount%pageSize==0)
            {
                pageCount=rowCount/pageSize;
            }else
            {
                pageCount=rowCount/pageSize+1;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally
        {
            this.close();
        }
        return pageCount;
    }
    /**得到用户需要显示的用户信息(分页)
     * @author luowei
     * @param 当前页
     * @return
     */
    public ArrayList getUserByPage(int pageNow)
    {
        ArrayList al=new ArrayList();
        try {
            //得到连接
            ct=new ConnDB().getConn();
            //3.创建Statement
            Statement sm=ct.createStatement();
            //查询出需要显示的记录
            rs=sm.executeQuery("select * from users order by useId limit "+(pageSize*(pageNow-1))+","+pageSize);
            //开始将rs封装到ArrayList
            while(rs.next())
            {
                UserBean ub=new UserBean();
                ub.setUserId(rs.getInt(1));
                ub.setUsername(rs.getString(2));
                ub.setPasswd(rs.getString(3));
                ub.setEmail(rs.getString(4));
                ub.setGrade(rs.getInt(5));
                al.add(ub);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            this.close();
        }
        return al;
    }
    /**@author luowei
     * @see关闭资源
     * @return null
     *
     */
    public void close()
    {
        try {
            if(rs!=null)
            {
                rs.close();
                rs=null;
            }
            if(sm!=null)
            {
                sm.close();
                sm=null;
            }
            if(ct!=null)
            {
                ct.close();
                ct=null;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

工具类_UserManageSys2/ src/user.model/Tools.java

/**
 * 工具类
 */
package user.model;
public class Tools {
    /**提供一个方法，将乱码转成gb2312,gbk,utf-8
     *
     * @param input
     * @return
     */
    public static String getNewString(String input)
    {
        String result="";
        try{
            result=new String(input.getBytes("gb2312"),"iso-8859-1");
        }catch(Exception e)
        {
            e.printStackTrace();
        }
        return result;
    }
}

连接数据库_UserManageSys2/ src/user.model/ConnDB.java

/**
 * 得到数据库的连接
 */
package user.model;
import java.sql.*;
public class ConnDB {
    private Connection ct=null;
    public Connection getConn()
    {
        try {
            //1.加载驱动
            Class.forName("org.gjt.mm.mysql.Driver").newInstance();
            //Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
            //2.得到连接
            ct=DriverManager.getConnection("jdbc:mysql://localhost:3306/test_user","root","root");
            //ct=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databaseName=testusr","sa","luowei");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ct;
    }
}

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