java - 如何在java中对这个数组列表进行排序

Question

我正在使用 OpenCsv 访问一个文件，我希望对其进行排序，然后写回另一个文件名。对列表进行排序时遇到问题。谢谢。

我正在尝试按第一列和第二列对 csv 文件进行排序。

 CSVReader reader = new CSVReader(new FileReader("d:\\temp\\data1.csv"), ',', '"', 1);

 //Read all rows at once
 List<String[]> allRows = reader.readAll();

 //Read CSV line by line and use the string array as you want
 for(String[] row : allRows){
    System.out.println(Arrays.toString(row));
 }

 *Arrays.sort(allRows.toArray());*

 CSVWriter writer = new CSVWriter(new FileWriter("d:\\temp\\data1sorted.csv"));
 writer.writeAll(allRows);

 //close the writer
 writer.close();

运行此代码时出现以下错误:

Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.Comparable
    at java.util.ComparableTimSort.countRunAndMakeAscending(Unknown Source)
    at java.util.ComparableTimSort.sort(Unknown Source)
    at java.util.ComparableTimSort.sort(Unknown Source)
    at java.util.Arrays.sort(Unknown Source)
    at CompareCsv.main(CompareCsv.java:31)

Answer 1

这对你有帮助吗？

public static void main(String args[]) {
            ArrayList<String> animalList = new ArrayList<String>();

        animalList.add("Dog");
        animalList.add("Cat");
        animalList.add("Snake");
        animalList.add("Bison");

        System.out.println("Before Sorting:");
        for (String tmpStr : animalList) {
            System.out.println(tmpStr);
        }

        // sorting
        Collections.sort(animalList);

        System.out.println("After Sorting:");
        for (String tmpStr : animalList) {
            System.out.println(tmpStr);
        }
    }