Question

我从目录中获取所有文件，然后根据需要从中挑选文件并将它们存储在数组中，现在我想对最后修改过的文件进行排序。这是我正在使用的代码

public static int GetFilesCount(File folderPath,int count,String type,Context context)
{
    BackupCount=count;
    BackupFolderPath=folderPath;
    Backuptype=type;
    con=context;
    DatabaseHandler objhandler;
    Cursor     cursor=null;
    int total = 0;
    String ext="";

    // Check files count set by user

    File[] fList = folderPath.listFiles();
    ArrayList<String> myfiles = new ArrayList<String>();

    for (File file : fList){
        if (file.isFile()){
            try {
                String FileName=file.getName();
                ext=GetFileExtension(FileName);
                if(ext.equals("db"))
                {
                    objhandler=new DatabaseHandler(context, folderPath+File.separator+FileName, null);
                    database= objhandler.openDataBase();
                    String selectQuery = "SELECT * FROM "+ type + " LIMIT 1";
                    cursor = database.rawQuery(selectQuery, null);
                    Integer ColCount=cursor.getColumnCount();
                    if(cursor.getCount()>0)
                    {
                        if(Backuptype.equals("SMS"))
                        {
                            if(ColCount.equals(9))
                            {
                                myfiles.add(FileName);

                                total++; 
                            }
                        }
                        else if(Backuptype.equals("CallLogs"))
                        {
                            if(ColCount.equals(6))
                            {
                                myfiles.add(FileName);
                                total++; 
                            }
                        }
                        else if(Backuptype.equals("Contacts"))
                        {
                            if(ColCount.equals(9))
                            {
                                myfiles.add(FileName);
                                total++; 
                            }
                        }
                    }    
                    if(total>count)
                    {
                        // String[] listFiles=new String[myfiles.size()];
                        // listFiles = myfiles.toArray(listFiles);
                        // File[] f = null;
                        for(int i=0;i<=myfiles.size();i++)
                        {
                            // f[i]=new File(folderPath+File.separator+myfiles.get(i));
                            System.out.println("Total SMS Files: "+myfiles.size());
                            System.out.println("file in folder: "+myfiles.get(i).toString());
                        }



                        /*Arrays.sort(f, new Comparator<File>(){
                          public int compare(File f1, File f2)
                          {
                          return Long.valueOf(f1.lastModified()).compareTo(f2.lastModified());
                          } });*/

                        System.out.println("file in folder: "+myfiles.size());
                        // Deletefile(folderPath+File.separator+myfiles.get(0));
                    }
                }


            }catch (Exception e) {
                e.printStackTrace();
                // TODO: handle exception
            }finally{
                cursor.close();
                database.close();
            }
        }
    }
    return 1;
}

Answer 1

尝试将这部分代码合并到您的代码中：

 final List<File> files = new ArrayList<File>();
    Collections.sort(files, new Comparator<File>()
    {

      @Override
      public int compare(final File o1, final File o2)
      {
        return o1.lastModified() >= o2.lastModified() ? 1 : -1;
      }

    });

Answer 2

来自你的评论：

我很困惑如何将所选文件放入File []

因为你有：

// File[] f = null;

我认为这是你缺少的部分

File[] f = new File[myfiles.size()]; // init the array which should hold the files
for(int i = 0; i < myfiles.size(); i++) {
    files[i] = new File(folderPath+File.separator+myfiles.get(i));
}

然后你可以使用Arrays.sort方法

Arrays.sort(files, new Comparator<File>() {
    @Override
    public int compare(File o1, File o2) {
        return Long.valueOf(o1.lastModified()).compareTo(o2.lastModified());
    }
});

更好的是，您应该使用List并使用Collections.sort

List<File> f = new ArrayList<>();
for(int i = 0; i < myfiles.size(); i++) {
    f.add(new File(folderPath+File.separator+myfiles.get(i)));
}

Collections.sort(f, new Comparator<File>() {
    @Override
    public int compare(File o1, File o2) {
        return Long.valueOf(o1.lastModified()).compareTo(o2.lastModified());
    }
});

如何按照上次修改的顺序对文件进行排序

2 个答案: