求助用户登陆的程序(连接数据库)

/**
   * 返回唯一实例.如果是第一次调用此方法,则创建实例
   * @return DBConnBean 唯一实例
   */
  static synchronized public DBConnBean getInstance() {
    if (instance == null) {
      instance = new DBConnBean();
    }
    clients++;
    return instance;
  }    /**
   * 获得一个可用的(空闲的)连接.如果没有可用连接,且已有连接数小于最大连接数
   * 限制,则创建并返回新连接
   *
   * @param name 在属性文件中定义的连接池名字
   * @return Connection 可用连接或null
   */
  public Connection getConnection(String name) {
    DBConnectionPool pool = (DBConnectionPool) pools.get(name);
    if (pool != null) {
      return pool.getConnection();
    }
    return null;
  }
  ObjDBConnBean=getInstance();
  Connection Conn=ObjDBConnBean.getConnection("goa");
  if (Conn==null) {
    response.sendRedirect("../index.jsp?MessageType=98");
    return;
  }else{
    ResultSet rs = null;
    Statement stmt = null;
    try {
      stmt = Conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
      strSql = "select PASSWORD,DEPTNAME,DEPTID,EMPLOYEE,EMPLOYEENAME,SUPERUSER";
      strSql = strSql + " from T_USERMAIN ";      rs = stmt.executeQuery(strSql);
登陆页面
<html>
<head>
<title>主页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<br><br>
<center><img src="images/tree.jpg" width="500" height="300"></center>
      <form name="myform" method="post" action="chklogin.jsp">
        <table width="23%" border="0" align="center" bgcolor="efefef">
          <tr>
            <td><br></td>
          </tr>
          <tr>
            <td width="37%" align="center">用户:</td>
            <td width="63%" align="center">
              <input type="text" name="username" size=14>
            </td>
          </tr>
          <tr>
            <td width="37%" align="center">密码:</td>
            <td width="63%" align="center">
              <input type="password" name="password" size=14>
            </td>
          </tr>
          <tr>
            <td colspan=2 align="center"><br><a href="javascript:myform.submit();">登陆</a>
                &nbsp&nbsp&nbsp&nbsp <a href="register.jsp">新用户注册</a>
            </td>
         </tr>
         <tr>
            <td><br></td>
          </tr>
        </table>
      </form>
</body>
</html>登陆验证<html>
<head>
<title>登陆验证</title>
</head>
<%@page import="java.util.*, java.sql.*" contentType="text/html;charset=GB2312" %>
<jsp:useBean id="pool" scope="application" class="connection.ConnPool"/>
<body>
<%
  boolean success=false; //是否能够登陆
  boolean valid=true; //是否重复登陆
  String username=new String(request.getParameter("username").getBytes("ISO8859_1"),"GBK");
  String password=new String(request.getParameter("password").getBytes("ISO8859_1"),"GBK");
  int rankid=0;
  //加载数据库驱动并用连接池连结数据库
  String sql="";
  Connection con = null;
  try{
      if (pool.getDriver()==null){
    pool.setDriver("sun.jdbc.odbc.JdbcOdbcDriver");
    pool.setURL("jdbc:odbc:MyForum");
    pool.setSize(5);
    pool.initializePool();
  }
      con = pool.getConnection();
      Statement statement = con.createStatement();
      sql="select * from Users where UserName='"+username+"' and Password='"+password+"'";
      ResultSet rs =statement.executeQuery(sql);
      if (rs.next()){
               success=true;
               rankid=rs.getInt("Rank");
       }else{
          success=false;
       }
  //释放数据库连结
      pool.releaseConnection(con);
  }catch (Exception e){
   out.println(e.getMessage());
   }
  //根据登陆结果判断
  Vector UserList=(Vector)session.getAttribute("userlist");
  if(UserList==null){
                     UserList=new Vector();
                    }
   if (success){
       session.setAttribute("username",username);
       UserList.addElement(username);
       //判断同一用户名是否重复登陆
       for(int i=0;i<UserList.size()-1;i++)
       {
          if(username.equals(UserList.elementAt(i).toString()))
          {
              UserList.removeElement(username);
              valid=false; %><h3>用户 <%=username%> 已经登陆，您不要再尝试用此用户名登陆了！</h3>
        <%}
       }
       if(valid)
       {
           session.setAttribute("userlist",UserList);
   session.setAttribute("username",username);
           response.sendRedirect("listboard.jsp?rankid="+String.valueOf(rankid));
       }
   }else{%>
          <h3>用户名或密码有误，请重新登录！</h3>
<%}%>
<a href="javascript:history.back();">返回</a>
</body>
</html>
还需要一个连接bean,可以自己写了

调试易

求助用户登陆的程序(连接数据库)

解决方案 »