Java: obtenga el archivo más nuevo en un directorio?

Question

¿Alguien tiene un fragmento de Java que puede devolver el archivo más reciente en un directorio (o conocimiento de una biblioteca que simplifica este tipo de cosas)?

Answer 1

Algo así como:

import java.io.File; 
import java.util.Arrays; 
import java.util.Comparator; 


public class Newest { 
    public static void main(String[] args) { 
     File dir = new File("C:\\your\\dir"); 
     File [] files = dir.listFiles(); 
     Arrays.sort(files, new Comparator(){ 
      public int compare(Object o1, Object o2) { 
       return compare((File)o1, (File)o2); 
      } 
      private int compare(File f1, File f2){ 
       long result = f2.lastModified() - f1.lastModified(); 
       if(result > 0){ 
        return 1; 
       } else if(result < 0){ 
        return -1; 
       } else { 
        return 0; 
       } 
      } 
     }); 
     System.out.println(Arrays.asList(files)); 
    } 
} 

Answer 2

Esto devuelve la última modificación:

public static File lastFileModified(String dir) { 
    File fl = new File(dir); 
    File[] files = fl.listFiles(new FileFilter() {   
     public boolean accept(File file) { 
      return file.isFile(); 
     } 
    }); 
    long lastMod = Long.MIN_VALUE; 
    File choice = null; 
    for (File file : files) { 
     if (file.lastModified() > lastMod) { 
      choice = file; 
      lastMod = file.lastModified(); 
     } 
    } 
    return choice; 
} 

Answer 3

Esto funciona perfectamente bien para mí:

import org.apache.commons.io.FileUtils; 
import org.apache.commons.io.comparator.LastModifiedFileComparator; 
import org.apache.commons.io.filefilter.WildcardFileFilter; 

... 

/* Get the newest file for a specific extension */ 
public File getTheNewestFile(String filePath, String ext) { 
    File theNewestFile = null; 
    File dir = new File(filePath); 
    FileFilter fileFilter = new WildcardFileFilter("*." + ext); 
    File[] files = dir.listFiles(fileFilter); 

    if (files.length > 0) { 
     /** The newest file comes first **/ 
     Arrays.sort(files, LastModifiedFileComparator.LASTMODIFIED_REVERSE); 
     theNewestFile = files[0]; 
    } 

    return theNewestFile; 
} 

Answer 4

En Java 8:

Path dir = Paths.get("./path/somewhere"); // specify your directory 

Optional<Path> lastFilePath = Files.list(dir) // here we get the stream with full directory listing 
    .filter(f -> !Files.isDirectory(f)) // exclude subdirectories from listing 
    .max(Comparator.comparingLong(f -> f.toFile().lastModified())); // finally get the last file using simple comparator by lastModified field 

if (lastFilePath.isPresent()) // your folder may be empty 
{ 
    // do your code here, lastFilePath contains all you need 
}  

Answer 5

private File getLatestFilefromDir(String dirPath){ 
    File dir = new File(dirPath); 
    File[] files = dir.listFiles(); 
    if (files == null || files.length == 0) { 
     return null; 
    } 

    File lastModifiedFile = files[0]; 
    for (int i = 1; i < files.length; i++) { 
     if (lastModifiedFile.lastModified() < files[i].lastModified()) { 
      lastModifiedFile = files[i]; 
     } 
    } 
    return lastModifiedFile; 
} 

Answer 6

public File getLastDownloadedFile() { 
    File choice = null; 
    try { 
     File fl = new File("C:/Users/" + System.getProperty("user.name") 
       + "/Downloads/"); 
     File[] files = fl.listFiles(new FileFilter() { 
      public boolean accept(File file) { 
       return file.isFile(); 
      } 
     }); 
     Thread.sleep(60000); 
     long lastMod = Long.MIN_VALUE; 

     for (File file : files) { 
      if (file.lastModified() > lastMod) { 
       choice = file; 
       lastMod = file.lastModified(); 
      } 
     } 
    } catch (Exception e) { 
     Reporter.log("Exception while getting the last download file :" 
       + e.getMessage()); 
    } 
    log.info("The last downloaded file is " + choice.getPath()); 
    Reporter.log("The last downloaded file is " + choice.getPath(),true); 
    return choice; 
}