Servlet:一个很难解释的问题

Question

String user_type = request.getParameter("user_type");
            page_top.setChargb("" + user_type + "");
            user_type = page_top.charset();
            if (request.getParameter("user_tel") == null ||
                "".equals(request.getParameter("user_tel"))) {
                user_tel = "NO";
            } else {
                user_tel = request.getParameter("user_tel");
                page_top.setCharset(user_tel);
                user_tel = page_top.charcall();
            }
            sql = "SELECT a.*, b.* FROM accept_list a INNER JOIN pub_user b ON a.user_id = b.user_id AND a.accept_time > '" +
                  start_time + "' AND a.accept_time < '" + end_time +
                  "' ";
            if (!"all".equals(what_board)) {
                sql = sql + "and b.user_channel='" + what_board + "'";
            }
            if (!"NO".equals(come_type) && !"all".equals(come_type)) {
                sql = sql + " and a.come_type='" + come_type + "'";
            }
            if (!"all".equals(user_air)) {
                sql = sql + " and a.user_air='" + user_air + "'";
            }
            if (!"NO".equals(admin_name) && !"all".equals(admin_name)) {
                sql = sql + " and a.worker_name='" + admin_name + "'";
            }
            if (!"all".equals(user_type)) {
                sql = sql + " and b.user_type='" + user_type + "'";
            }
            if (!"NO".equals(user_tel)) {
                sql = sql + " and b.user_tel like '" + user_tel + "'";
            }
            out.println(sql);
            try {
                int RowCount = 0;
                Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
                String url =
                        "jdbc:microsoft:sqlserver://134.164.10.8:1433;DatabaseName=tele";
                cn = DriverManager.getConnection(url, "tele", "totele");
                stem = cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                          ResultSet.CONCUR_READ_ONLY);
                rs = stem.executeQuery(sql);
                con = DriverManager.getConnection(url, "tele", "totele");
                stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                           ResultSet.CONCUR_READ_ONLY);                if (rs.next()) {
                    rs.beforeFirst();
                    while (rs.next()) {
                        userchannel = 0;
                        userchannel++;
                        qs = stmt.executeQuery(
                                "select admin_group,count(admin_group) as dd from pub_admin where admin_group='" +
                                rs.getString("user_channel") +
                                "' group by admin_group");
                        if (qs.next()) {
                            if(admingroup.indexOf(qs.getString("admin_group"),0)<0)
                            {
                                admingroup = admingroup + ";" +
                                             qs.getString("admin_group");
                                if (userchannel != 0) {
                                    out.println("<table width=\"98%\" bgcolor=\"#CCCCCC\"  border=\"0\" align=\"center\" cellpadding=\"0\" cellspacing=\"1\" style=\"margin-top: 3px\">");
                                    out.println(
                                            "<tr height=\"25\" bgcolor=\"D0E9FF\">");
                                    out.println("<td align=\"center\">部门</td>");
                                    out.println("<td align=\"center\">" +
                                                qs.getString("admin_group") +
                                                "</td>");
                                    out.println(
                                            "<td align=\"center\">用户态度:</td>");
                                    out.println("<td align=\"center\">");
                                    out.println(
                                            "<table width=\"100%\"  border=\"0\" cellspacing=\"1\" cellpadding=\"1\">");
                                    out.println("<tr>");

Answer 1

strm=cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                           ResultSet.CONCUR_READ_ONLY);
                                    cs=strm.executeQuery("select type_value,type_name from value_type where type_kind='B'");
                                    while(cs.next())
                                    {
                                        out.println("<td align=\"center\">"+cs.getString("type_name")+"</td>");
                                    }
                                    out.println("</tr><tr>");
                                    cs.beforeFirst();
                                    while(cs.next())
                                    {
                                        out.println("<td align=\"center\">");
                                        stmm=cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                           ResultSet.CONCUR_READ_ONLY);
                                        ds=stmm.executeQuery("select count(b.user_air) as dd from pub_user a,accept_list b where a.user_id=b.user_id and b.user_air='"+cs.getString("type_value")+"' and a.user_channel='"+qs.getString("admin_group")+"' group by b.user_air");
                                        if(!ds.next())
                                        {
                                            out.println("0");
                                        }
                                        else
                                        {
                                            ds.beforeFirst();
                                            while(ds.next())
                                            {
                                                out.println(""+ds.getString("dd")+"");
                                            }
                                        }
                                        ds.close();
                                        ds=null;
                                        stmm.close();
                                        stmm=null;
                                        out.println("</td>");
                                    }
                                    cs.close();
                                    cs=null;
                                    strm.close();
                                    strm=null;
                                    out.println("</tr>");
                                    out.println("</table>");
                                    out.println("</td>");
                                    out.println("<td align=\"center\">总数:</td>");
                                    out.println("<td align=\"center\">" +
                                                userchannel +
                                                "</td>");
                                    out.println("</tr>");
                                    out.print("</table>");
                                }
                            }
                        }
                        qs.close();
                        qs = null;
                    }
                }
                rs.close();
                rs = null;
                stem.close();
                stem = null;
                cn.close();
                cn = null;            } catch (Exception e1) {
                out.println(e1.getMessage());
            }
        }
        out.println("</body>");
        out.println("</html>");
        out.close();
    }    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        doGet(request, response);
    }    //Clean up resources
    public void destroy() {
    }
}

Answer 2

String starttime = "" + date.get(Calendar.YEAR) + "-" +
                               (date.get(Calendar.MONTH) + 1) + "-" +
                               date.get(Calendar.DATE) + " " +
                               date.get(Calendar.HOUR_OF_DAY) + ":" +
                               date.get(Calendar.MINUTE) + ":" +
                               date.get(Calendar.SECOND) + "";
这个地方可以这样写String starttime = new java.util.Date().toLocaleString();

Answer 3

这么长的代码，而且混杂着html，让人怎么看么。
建议你用jsp+javabean

Answer 4

楼上的说得对，最好是jsp+servlet+bean
servlet把东西查出来放到list里然后传给页面，
还有一点:public class stat_list extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";
    private String sql="";
    private String come_type="";
    private String admin_name="";
    private String user_tel="";
    Connection cn, con = null;
    Statement stem, stmt = null;
    ResultSet rs, qs = null;
    private int i = 0;
    private int userchannel=0;
    private String admingroup="部门";
    private Statement strm=null;
    private ResultSet cs=null;
    private Statement stmm=null;
    private ResultSet ds=null;
这个千万不要用，你程序出问题估计是这儿(呵呵，太长了，没时间看你的程序)
千万不要在Servlet里写类变量,因为对于Servlet而言，
如果在同一时间有多个Http来请求这个request(都用的同一个URL的话，那么，这个servlet执行时只有一份实例，所以一般在servlet里都是传bean的，除非你这个量在所有的访问里都是一样的，对于Struts的Action而言也一样)

Answer 5

....把CSDN 当智能Debug工具了

Answer 6

如果楼主要做的系统很大的话，试试struts框架吧！

Answer 7

javabean如果同时接收两个不同机器传过来的值会不会传错？