Question

我正在尝试使用jdbc连接池，因为我创建了IntialContext obj和datasource obj，并将“dsjndi”作为initialcontext的查找方法的参数，但是当我运行我的项目项目时它显示“”名称[dsjndi ]不受此上下文的约束。找不到[dsjndi]。“” 任何人都可以指导我的问题是什么？

Connection con = null;
Statement st = null;
ResultSet rs = null;
ResultSetMetaData rsmd = null;
public void process(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException 
{
    //general settings 
    //get print Writer obj
    PrintWriter pw = res.getWriter();
    //set content type 
    res.setContentType("text/html");
    //read form data 
    String tableName = req.getParameter("table");
    try
    {
        //get con obj from jdbc con pool
        con = makeConnection();
        //create Statement obj
        st = con.createStatement();
        //execute query
        rs = st.executeQuery("select * form" +tableName);
        //use metadata obj to get db vlaues along with the col names 
        rsmd = rs.getMetaData();
        int cnt = rsmd.getColumnCount();
        pw.println("<hmtl><body bgcolor='#ffffa9'>");
        pw.println("<center><h3>the details of the table" +tableName);
        pw.println("<br><br><table cellsapcing='1' bgcolor='#00ff00'>");
        pw.println("<tr bgcolor='#ffffa9'>");
        //pritnt col names 
        for(int col=1;col<=cnt;col++)
        {
            pw.println("<th>" +rsmd.getColumnLabel(col)+ "&nbsp;&nbsp");
        }
        pw.println("</tr>");
        //print col values
        while(rs.next())
        {
            pw.println("<tr bgcolor='#ffffa9'>");
            for(int i=1;i<=cnt;i++)
            {
                pw.println("<td>" +rs.getString(i)+ "&nbsp;&nbsp;</td>");
            }
            pw.println("</td>");
        }//while
        pw.println("<table><br/>");
        pw.println("<b>to view another table</b><ahref='index.html'>click here</a>");
        pw.println("</body></html>");
    }//try
    catch(Exception e)
    {
        e.printStackTrace();
    }
}
private Connection makeConnection()
{
    Connection con = null;
    try
    {
        //get IntialConetext 
        InitialContext ic = new InitialContext();
        //get data sourse obj
        DataSource ds = (DataSource) ic.lookup("DsJndi");
        //get jdbc con obj from con pool 
        con = ds.getConnection();
    }//try
    catch(Exception e)
    {
        e.printStackTrace();
    }
    return con;
}//make Connection
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException 
{
    process(req,res);
}
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
{
    process(req,res);           
}

}

名称[dsjndi]未在此上下文中绑定。无法找到[dsjndi]

0 个答案: