Question

我有一个返回大量结果的SQL查询（不幸的是，结果的数量会有所不同）。目前，我将结果存储到arrayList中，如下所示：

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 = (((result_data = result.getObject("sDate"))==null || result.wasNull())?" ":result_data.toString());
      allTerms.add(sDate);
  }
  System.out.println(allTerms);

好的，所以当我运行它时，系统会输出：

[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]

我不知道这是否是正确的做法，但它到目前为止工作，所以我现在要做的是使用我的allTerms arrayList将这些结果传输到HTML页面的某些部分。所以对于前：

<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>

Answer 1

如果你只是定义一个短值持有者类，那就容易多了，比如：

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

然后，定义一个包含这些行值的集合：

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

并将行添加到列表中：

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());      
}

现在您可以过滤集合，如下所示：

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

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

帮助循环遍历ArrayList以仅获取特定结果

1 个答案: