如何在Android中按升序或降序按文件名或日期排序文件或文件夹？

以下示例代码来自Internet，我希望按文件名以升序或降序对the List<String> files进行排序。我希望能通过升序或降序的L ist<String> files文件的日期，我该怎么办？谢谢！如何在Android中按升序或降序按文件名或日期排序文件或文件夹？

与List<String> directories相同的制式。

List<String> files = Arrays.asList(f.list(new FilenameFilter() { 
     @Override 
     public boolean accept(File dir, String name) { 
      File f=new File(dir, name);    

      return f.isFile()&&(f.isHidden()==false); 
     } 
    })); 
    Collections.sort(files); 




List<String> directories = Arrays.asList(f.list(new FilenameFilter() { 
    @Override 
    public boolean accept(File dir, String name) { 
     File f=new File(dir, name); 
     return f.isDirectory()&& (f.isHidden()==false); 
    } 
})); 
Collections.sort(directories);

来源

2016-07-29 HelloCW

只需提供您的文件数组，并且它排序简单。

Arrays.sort(files, new Comparator<File>() { 
    public int compare(File f1, File f2) { 
     return Long.compare(f1.lastModified(), f2.lastModified()); 
    } 
});

演示：

@Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 


     File path = Environment.getExternalStoragePublicDirectory("/DCIM/Camera"); 
     File[] filesList = path.listFiles(); 
     for (int i = 0; i < filesList.length; i++) { 
      Date lastModDate = new Date(filesList[i].lastModified()); 
      Log.i("Pre sorted", "File last modified @ : " + lastModDate.toString()); 
     } 

     Arrays.sort(filesList, new Comparator<File>() { 
      public int compare(File f1, File f2) { 
       return Long.compare(f1.lastModified(), f2.lastModified()); 
      } 
     }); 
     Log.i("sorted", "----------------------------------------"); 
     for (int i = 0; i < filesList.length; i++) { 
      Date lastModDate = new Date(filesList[i].lastModified()); 
      Log.i("Pro sorted", "File last modified @ : " + lastModDate.toString()); 
     } 
    }

来源

2016-07-29 06:18:04

谢谢！给Sohail Zahid：但是你的代码不起作用 – HelloCW

错误的第二个参数类型。发现：'java.util.Comparator '，必需：'java.util.Comparator <？ super java.lang.Object>' – HelloCW

请显示你如何使用这段代码？ –

您可以使用如下的排序基于文件名和更改日期等比较该值。或者干脆用ApacheCommons，它会给直接的API

File[] directoryList = currentFolder.listFiles(); 
if (directoryList != null) { 
    List<File> directoryListing = new ArrayList<File>(); 
    directoryListing.addAll(Arrays.asList(directoryList)); 
    Collections.sort(directoryListing, new SortFileName()); 
    Collections.sort(directoryListing, new SortFolder()); 
} 


//sorts based on the files name 
public class SortFileName implements Comparator<File> { 
    @Override 
    public int compare(File f1, File f2) { 
      return f1.getName().compareTo(f2.getName()); 
    } 
} 

//sorts based on a file or folder. folders will be listed first 
public class SortFolder implements Comparator<File> { 
    @Override 
    public int compare(File f1, File f2) { 
     if (f1.isDirectory() == f2.isDirectory()) 
      return 0; 
     else if (f1.isDirectory() && !f2.isDirectory()) 
      return -1; 
     else 
      return 1; 
      } 
}

来源

2016-07-29 06:24:59 jettimadhuChowdary

如何在Android中按升序或降序按文件名或日期排序文件或文件夹？

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