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help with looping through an ArrayList to only get specific results

开发者 https://www.devze.com 2023-03-13 16:23 出处:网络
I have a SQL query that returns a number of results (unfortunately, the number of results will vary).Currently, I am storing the results into an arrayList like so:

I have a SQL query that returns a number of results (unfortunately, the number of results will vary). Currently, I am storing the results into an arrayList like so:

ArrayList allTerms = new ArrayList();


try {

  String selStmt = "SELECT .... ";

  stmt = conn.prepareStatement(selStmt);
  result = stmt.executeQuery();
  Object result_data;

  while (result.next()) {    
      term = (((result_data = result.getObject("internal_code"))==null || result.wasNull())?" ":result_data.toString());
      allTerms.add(term);
      desc = (((result_data = result.getObject("external_representation"))==null || result.wasNull())?" ":result_data.toString());
      allTerms.add(desc);
      sorter = (((result_data = result.getObject("sorter"))==null || result.wasNull())?" ":result_data.toString());
      allTerms.add(sorter);
      sDate = (开发者_运维技巧((result_data = result.getObject("sDate"))==null || result.wasNull())?" ":result_data.toString());
      allTerms.add(sDate);
  }
  System.out.println(allTerms);

Okay, so when I run this, the system prints:

[2011SP, Spring 2011, 1, 11-15-2010, 2011SU, Summer 2011, 1, 01-15-2011, 2011FL, Fall 2011, 1, 04-01-2011, 2010Q2, CE Qtr 2 2010 Dec - Feb, 2, 08-01-2010, 2011Q3, CE Qtr 3 2011 Mar - May, 2, 11-01-2010, 2011Q4, CE Qtr 4 2011 Jun - Aug, 2, 02-01-2011, 2011Q1, CE Qtr 1 2011 Sep-Nov, 2, 05-01-2011]

I dont know if this is the correct way of doing it or not, but it is working so far, so what I want to do now is use my allTerms arrayList to transfer these results to parts of a HTML page. so for ex:

<table class="t1">
  <tr>
    <td><!--Here I would want to show all rows from the allTerms arrayList with a "sorter" of 1--></td>
  </tr>
</table>
<table class="t2">
  <tr>
    <td><!--Here I would want to show all rows from the allTerms arrayList with a "sorter" of 1 and a term of ....SU (where '....' is the year) --></td>
  </tr>
</table>


It's a lot easier if you just define a short value holder class, like:

public class Row {  // give it a better name ;)
  public String internalCode;
  public String externalRepresentation;
  public String sorter;
  public String sDate;
}

then, define a collection that holds these row values:

List<Row> rows = new ArrayList<Row>();

and add the rows to the list:

while (result.next()) {    
      Row row = new Row();
      row.internalCode = (((result_data = result.getObject("internal_code"))==null || result.wasNull())?" ":result_data.toString());
      row.externalRepresentation = (((result_data = result.getObject("external_representation"))==null || result.wasNull())?" ":result_data.toString());
      row.sorter = (((result_data = result.getObject("sorter"))==null || result.wasNull())?" ":result_data.toString());
      row.sDate = (((result_data = result.getObject("sDate"))==null || result.wasNull())?" ":result_data.toString());      
}

Now you can filter on the collection like this:

 for (Row row:rows) {
   if (!row.sorter.equals("1"))
     continue;

   // do what has to be done with records where sorter = "1"
 }
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