【问题】

i have csv as input with 2 columns and want to sort data on basis of date column (dd/mm/yyyy). below code sort the date correctly but i want the related value with that date... output of this code is like

02/05/2012

09/11/2012

10/11/2012

Code:

public static void main(String[] args){
    Date value = null;
    String reader ="";
    String[] input = null ;
    Date date;
    List<Date> dateList = new ArrayList<Date>();
    SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy");
    File file = new File("data.csv");

    try {
        BufferedReader br = new BufferedReader(new FileReader(file));
        while((reader = br.readLine())!=null){             
            input = reader.split(",");             
             date = df.parse(input[0]);
             dateList.add(date);
        }

        Collections.sort(dateList, new Comparator<Date>() {
             public int compare(Date o1, Date o2){
                return o1.compareTo(o2);
             }
        });

         for(Date x : dateList){
             System.out.println(df.format(x));              
         }
    } catch (FileNotFoundException fi) {
       fi.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch(ParseException pe){
        pe.printStackTrace();
    }      
}

【回答】

对记录排序并取某字段，这是最简单的结构化算法，但JAVA缺乏相关的类库，需要自行编写大量代码。这种情况下可以用SPL辅助JAVA来实现。

假设原始数据是：

date,value

10/11/2012,300

02/05/2012,100

09/11/2012,200

脚本如下：

A1：读取文本

A2：按照date排序后取value值，结果如下：

写好的脚本如何在应用程序中调用，可以参考