基于列的日期排序java的csv文件 [英] Java sort a csv file based on column date

问题描述

需要梳理的基础上的日期列csv文件。这是masterRecords数组列表的样子

Need to sort a csv file based on the date column. This is how the masterRecords array list looks like

GBEP-1-2-4,FRAG,PMTypeEthernet,NEND,TDTN,15-MIN,Dec 15 2014  - 07:15:00 AM MYT,+0,COMPL
GBEP-1-2-1,FRAG,PMTypeEthernet,NEND,TDTN,15-MIN,Dec 15 2014  - 07:00:00 AM MYT,+0,COMPL
GBEP-2-2-1,FRAG,PMTypeEthernet,NEND,TDTN,15-MIN,Dec 15 2014  - 07:30:00 AM MYT,+0,COMPL

我需要从我创建了一个code梳理出来日七时15分00秒，七点30分00秒，等它基于梳理：

I need to sort it out based from the date 07:15:00, 07:30:00, etc. I created a code to sort it out:

// Date is fixed on per 15min interval
ArrayList<String> sortDate = new ArrayList<String>();
    sortDate.add(":00:");
    sortDate.add(":15:");
    sortDate.add(":30:");
    sortDate.add(":45:");

    BufferedWriter bw = new BufferedWriter(new FileWriter(tempPath + filename));

    for (int k = 0; k < sortDate.size(); k++) {
        String date = sortDate.get(k);
        for (int j = 0; j < masterRecords.size(); j++) {
            String[] splitLine = masterRecords.get(j).split(",", -1);
            if (splitLine[10].contains(date)) {
                bw.write(masterRecords.get(j) + System.getProperty("line.separator").replaceAll(String.valueOf((char) 0x0D), ""));
                masterRecords.remove(j);
            }
        }
    }
bw.close();

您可以从上面它会看到环通的第一阵列（sortDate）和环路直通再次第二个数组这是masterRecord，写在一个新的文件上。这似乎为新的文件整理出来进行工作，但我发现我的masterRecord有10000条记录，但创建一个新文件记录收缩到5000后，林假设它如何从主列表中删除的记录。任何人都知道这是为什么？

You can see from above it will loop thru a first array (sortDate) and loop thru again on the second array which is the masterRecord and write it on a new file. It seems to be working as the new file is sorted out but I notice that my masterRecord has 10000 records but after creating a new file the record shrinks to 5000, Im assuming its how I remove the records from the master list. Anyone knows why?

推荐答案

是不是安全地删除一个循环内的项目。
您对迭代器遍历数组，例如：

Is not safe to remove an item inside of a loop. You have to iterate array over Iterator, for example:

List<String> names = ....
Iterator<String> i = names.iterator();
while (i.hasNext()) {
   String s = i.next(); // must be called before you can call i.remove()
   // Do something
   i.remove();
}

该文件说：

此类的iterator和listIterator方法返回的迭代器是快速失败的：如果列表随时结构上修改迭代器创建之后，以任何方式，除了通过迭代器自身的remove或add方法，迭代器将抛出一个ConcurrentModificationException的。因此，在并发的修改，迭代器很快就会完全失败，而不是在将来不确定的时间任意冒险，不确定性的行为。

The iterators returned by this class's iterator and listIterator methods are fail-fast: if the list is structurally modified at any time after the iterator is created, in any way except through the iterator's own remove or add methods, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.

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