How to display the data column on jsp

My requirements: Display total error count of error description of each database server (column wise). like this:

Description DBServer1 DBServer2

Error1 10 22

Error2 20 30

Error3 66 32 ..

in table of each database having two columns: description, error. but data is dynamic. one database having 2 rows and another database could have 10 rows. so database should be mapped.(error with descrption)

program read a properties file where database server ip is defined and fill a array list with database server ip's. and using a loop over this database server ips to create db connection and all the tasks.

                HashMap hm=null;

                public HashMap getHm() {
                    return hm;
                }

                public void setHm(HashMap hm) {
                    this.hm = hm;
                }
                public  String countErrorData(){

                    //String[][] tempArray = null;
                    // ReadDBFile();
                     hm=new HashMap();
                     for (int j=0; j<dbSizeList.size();j++){
                             //mdList= new ArrayList();
                             //ArrayList errorCountList1= new ArrayList();
                             serverurl=String.valueOf(dbSizeList.get(j));
                            try {   
                                String connectionUrl=null;
                                 Class.forName("com.mysql.jdbc.Driver");

                                     connectionUrl = "jdbc:mysql://"+serverurl+":"+Global.myport+"/"+Global.database+"?" +
                                                           "user="+Global.myuser2+"&password="+Global.mypasswod+"&autoReconnect=true&useUnicode=true&characterEncoding=utf8";
                                    conn = DriverManager.getConnection(connectionUrl);
                                    stmt=conn.createStatement(); 

                    query="select distinct err as Description,count(error) as TotalErrors from tablename where err!='NA' GROUP by ERR ORDER BY TotalErrors desc";

                    System.out.println("error query:"+query);
                    try {
                         ArrayList errorList= new ArrayList();
                         rs=stmt.executeQuery(query);
                        rs.last();
                        row_count=rs.getRow();
                        rs.beforeFirst();
                        column_count=dbSizeList.size();
                        //tempArray = new String[row_count][column_count];

                         while (rs.next())
                         {
                            hm.put(rs.getString(1), rs.getString(2));
                            //errorCountList1.add(rs.getString(2));
                        }
                        dbURLList.add(serverurl);
                        /*for(int row=0; row < row_count; row++){
                            for (int i = z; i <= z; i++) {
                                tempArray[row][i] =(String)errorCountList1.get(row);
                                System.out.println("tempArray["+row+"]["+i+"]: "+tempArray[row][i]);
                                mdList.add(tempArray[row][i]);
                                }
                         }*/
                    }
                    catch(Exception e){

                        e.printStackTrace();
                    }
                            }catch(Exception e)
                            {
                                e.printStackTrace();
                            }

                        }
                        request.setAttribute("row_count", String.valueOf(row_count));
                        request.setAttribute("column_count", String.valueOf(column_count));
                        request.setAttribute("dbURLList", dbURLList); 
                        return "success";
                }

            jsp code:
                    <form id="myForm"   method="post">
                     <% 
                String column_count= (String)request.getAttribute("column_count");
                List dbURLList= (List)request.getAttribute("dbURLList"); 
                    %>
                <H2 align="center">Error Details</H2>
                <table  border="1" align="center">
                <tr><td>Description</td>
                <% for (int i = 0; i < Integer.parseInt(column_count); i++) { %>
                <td>  <%=dbURLList.get(i)%>  </td>
                <% }  %> 
                </tr>
                <c:forEach items="${hm}" var="entry">
                <tr><td>  ${entry.key}</td><td>  ${entry.value}</td></tr>
                </c:forEach>
                </table>
                </form>


            It display the data of last database server and it show in first column of database server column.
            suppose i have 2 database. it is showing like this:

            Description      localhost      localhost  
            Error1           138086
            Error2           1500
            Error3            99


            How i deal with this situtaion. should i set the data in a pojo and display the data in row wise. but database server ip is not fix. there may be 2 database or may be 5 database.
            Mapping (decription with error count of each database) on jsp is also a issue .

June 9, 2017 at 10:12 PM

Hi,

In your code:

 while (rs.next())
              {
              hm.put(rs.getString(1), rs.getString(2));
              //errorCountList1.add(rs.getString(2));
              }

After getting data rs.getString(1) you can dispaly with the code out.println(rs.getString(1)) on jsp page.

Please check tutorial: Display Data from Database in JSP.

Thanks