Question

i am fetching all data from database and stored the resultset to a list. but could not fetch all data. i want to store the data in a dropdownlist. My code is bellow.

public static void updateChallan(){
    ChallanNumber pd=null;
    int i=0;
    String customerName="";
    List<ChallanNumber> challanList= new ArrayList<ChallanNumber>();
    Connection con = DB.getConnection();
    try
    {
    String st="select CHALLAN_NUMBER,CUSTOMER_CODE,CHALLAN_DATE from DELIVERY_CHALLAN_DETAILS order by CHALLAN_NUMBER";
    Statement stmt=con.createStatement();
    ResultSet rs=stmt.executeQuery(st);
    while(rs.next())
    {
        String stCustName="select CUSTOMER_NAME from CUSTOMER_DETAILS where CUSTOMER_CODE='"+rs.getString(2)+"'";
        Statement stmtCustName=con.createStatement();
        ResultSet rsCustName=stmtCustName.executeQuery(stCustName);
        while(rsCustName.next()){
            customerName=rsCustName.getString(1);
        }

        customerName=rsCustName.getString(1);
        //System.out.println(customerName +" "+i);
        pd=new ChallanNumber(rs.getString(1),customerName,rs.getString(3));
        challanList.add(i,pd);
        i++;
    }
    }
    catch(Exception e)
    {
        //e.printStackTrace();
    }
    render(challanList);
}

Dropdownlish code is in bellow.

<select name="challanNumber" id="challanNumber">
              <option value="selected" selected="selected">ChallanNumber-CustomerCode-    Date</option>

              #{list challanList, as:'cl'}

              <option value="${cl.challanNumber}">${cl.challanNumber}(${cl.customercode}-${cl.challanDate})</option>

                #{/list}



            </select>

Answer 1

You need to close everything you open, it means statement, resultsets. You do that in the finally part of your try/catch to ensure things are correctly closed.

When you close a statement, the resultset linked to that statement is closed too.

public static void updateChallan() throws Exception {
    ChallanNumber pd = null;
    int i=0;
    String customerName = "";
    List<ChallanNumber> challanList= new ArrayList<ChallanNumber>();
    Connection con = DB.getConnection();
    Statement stmt = null;
    try {
        String st = "select CHALLAN_NUMBER,CUSTOMER_CODE,CHALLAN_DATE from DELIVERY_CHALLAN_DETAILS order by CHALLAN_NUMBER";
        stmt = con.createStatement();
        ResultSet rs = stmt.executeQuery(st);
        while (rs.next()) {
            String stCustName = "select CUSTOMER_NAME from CUSTOMER_DETAILS where CUSTOMER_CODE='" + rs.getString(2) + "'";
            Statement stmtCustName = con.createStatement();
            try {
                ResultSet rsCustName = stmtCustName.executeQuery(stCustName);
                while (rsCustName.next()){
                    customerName = rsCustName.getString(1);
                }
            } finally {
                if (stmtCustName != null) 
                    stmtCustName.close();
            }

            customerName = rsCustName.getString(1);
            //System.out.println(customerName +" "+i);
            pd = new ChallanNumber(rs.getString(1), customerName, rs.getString(3));
            challanList.add(i, pd);
            i++;
        }
    } catch(Exception e) {
        e.printStackTrace();
    } finally {
        if (stmt != null) 
            stmt.close();
    }
    render(challanList);
}

Besides, you should read the docs of PlayFramework (here for Play2) there are database stuff to avoid using ResultSets and Statements directly, dealing with higher structures like domain objects, the framework will do the rest for you.