Listing Last 10 Modified Files In Directory

Programming Questions

Kelvin Me..

Listing Last 10 Modified Files In Directory

in Programming Questions • 1 month ago

Hi,

Im using the following code to get the last image in a directory, but i wish to get the last 9 images.

I have adapted this code for 9 images

this is just the part of the code i am having issues with currently.

import java.io.*;
FilenameFilter jpgFilter = new FilenameFilter() {
boolean accept(File dir, String name) {
return name.toLowerCase().endsWith(".jpg");
}
};
PImage img = null;
void setup() {
size(1200, 900);
}
void draw() {
if (img != null) {
image(img, 0, 0);
}
}
void folderSelected(File folder) {
if (folder == null) {
println("Window was closed or the user hit cancel.");
}
else {
File[] files = folder.listFiles(jpgFilter);
long timeTest = 0;
File lastImage = null;
for (int i = 0; i < files.length; i++) {
if (files[i].lastModified() > timeTest) {
timeTest = files[i].lastModified();
lastImage = files[i];
}
println(files[i] + " : " + files[i].lastModified());
}
println();
println(lastImage.getPath());
img = loadImage(lastImage.getPath());
}
}
void keyPressed() {
if (key == ' ') {
selectFolder("Select a folder to process:", "folderSelected");
}
}

and here is the adapted code;

import java.io.*;
FilenameFilter jpgFilter = new FilenameFilter() {
boolean accept(File dir, String name) {
return name.toLowerCase().endsWith(".jpg");
}
};
PImage img1 = null;
PImage img2 = null;
PImage img3 = null;
PImage img4 = null;
PImage img5 = null;
PImage img6 = null;
PImage img7 = null;
PImage img8 = null;
PImage img9 = null;
void setup() {
size(1200, 900);
}
void draw() {
if (img1 != null) {
image(img1, 0, 0);
}
if (img2 != null) {
image(img2, 0, 0);
}
if (img3 != null) {
image(img3, 0, 0);
}
if (img4 != null) {
image(img4, 0, 0);
}
if (img5 != null) {
image(img5, 0, 0);
}
if (img6 != null) {
image(img6, 0, 0);
}
if (img7 != null) {
image(img7, 0, 0);
}
if (img8 != null) {
image(img8, 0, 0);
}
if (img9 != null) {
image(img9, 0, 0);
}
}
void folderSelected(File folder) {
if (folder == null) {
println("Window was closed or the user hit cancel.");
}
else {
File[] files = folder.listFiles(jpgFilter);
long timeTest = 0;
File lastImage1 = null;
File lastImage2 = null;
File lastImage3 = null;
File lastImage4 = null;
File lastImage5 = null;
File lastImage6 = null;
File lastImage7 = null;
File lastImage8 = null;
File lastImage9 = null;
for (int i = 0; i < files.length; i++) {
if (files[i].lastModified() > timeTest) {
timeTest = files[i].lastModified();
lastImage1 = files[i];
lastImage2 = files[i-1];
lastImage3 = files[i-2];
lastImage4 = files[i-3];
lastImage5 = files[i-4];
lastImage6 = files[i-5];
lastImage7 = files[i-6];
lastImage8 = files[i-7];
lastImage9 = files[i-8];
}
println(files[i] + " : " + files[i].lastModified());
}
println();
println(lastImage1.getPath());
img1 = loadImage(lastImage1.getPath());
img2 = loadImage(lastImage2.getPath());
img3 = loadImage(lastImage3.getPath());
img4 = loadImage(lastImage4.getPath());
img5 = loadImage(lastImage5.getPath());
img6 = loadImage(lastImage6.getPath());
img7 = loadImage(lastImage7.getPath());
img8 = loadImage(lastImage8.getPath());
img9 = loadImage(lastImage9.getPath());
}
}
void keyPressed() {
if (key == ' ') {
selectFolder("Select a folder to process:", "folderSelected");
}
}

and the errors...

java.lang.reflect.InvocationTargetException

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:597)

at processing.core.PApplet.selectCallback(PApplet.java:6697)

at processing.core.PApplet.access$000(PApplet.java:158)

at processing.core.PApplet$6.run(PApplet.java:6684)

at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)

at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:715)

at java.awt.EventQueue.access$400(EventQueue.java:82)

at java.awt.EventQueue$2.run(EventQueue.java:676)

at java.awt.EventQueue$2.run(EventQueue.java:674)

at java.security.AccessController.doPrivileged(Native Method)

at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:86)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:685)

at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)

at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)

at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

Caused by: java.lang.ArrayIndexOutOfBoundsException: -1

at sketch_130820d.folderSelected(sketch_130820d.java:98)

... 21 more

now i think the issue is the for loop starting at 0, and trying to -1 from it, but i don't know how to get around it.

or if there is a plainer way?

thanks!

Replies(10)

GoToLoop

Re: Listing Last 10 Modified Files In Directory

1 month ago

Life would be easier if programmers used an Array or another composite to store related data.
Nevertheless, I've converted img1 up to img9 to PImage[].
So as to be much easier to deal with them from now on!
Also, implemented an Array.sort() w/ Comparator, using ( f2.lastModified() - f1.lastModified() )
as a parameter to determine which 1 has been more recently modified.

/** 
 * Display by Last Modified (v2.51)
 * by Kelvin Mead (2013/Aug)
 * mod GoToLoop
 * 
 * http://forum.processing.org/topic/
 * listing-last-10-modified-files-in-directory
 */

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

final FilenameFilter jpgFilter = new FilenameFilter() {
  boolean accept(File dir, String name) {
    return name.toLowerCase().endsWith(".jpg");
  }
};

final Comparator lastModifiedComparator = new Comparator<File>() {
  int compare(File f1, File f2) {
    return 1 | (int) (f2.lastModified() - f1.lastModified() >> 63);
    //return Long.signum(f2.lastModified() - f1.lastModified());
  }
};

final static int NUM = 10;
final PImage[] imgs = new PImage[NUM];

final static float FPS = .5;
final static color BG = 0;
int cw, ch;

void setup() {
  size(1100, 800);
  frameRate(FPS);
  imageMode(CENTER);
  background(BG);

  cw = width>>1;
  ch = height>>1;
}

synchronized void draw() {
  if (imgs[frameCount %= NUM] == null)  frameCount = 0;

  if (imgs[frameCount] != null) {
    background(BG);
    image(imgs[frameCount], cw, ch);
    frame.setTitle("Image #" + (frameCount + 1));
  }
}

void mouseClicked() {
  selectFolder("Select a folder to process:", "folderSelected");
}

void folderSelected(File folder) {
  if (folder == null) {
    println("Window was closed or the user hit cancel.");
    return;
  }

  final File[] files = folder.listFiles(jpgFilter);
  Arrays.sort(files, lastModifiedComparator);

  final int num = min(NUM, files.length);

  synchronized(this) {
    Arrays.fill(imgs, null);
    for (int i = 0; i != num; imgs[i] = loadImage(files[i++].getPath()));
    frameCount = NUM;
  }
}

Kelvin Me..

Re: Listing Last 10 Modified Files In Directory

1 month ago

thanks!

i've only been processing for 2 days now so i doubt that i would be called a programmer but i will look into arrays as the rest of the code is an awful lot of copy/paste/number change!

i will implement this in the morning!

GoToLoop

Re: Listing Last 10 Modified Files In Directory

1 month ago

Array data-type is the most basic composite in any programming language.

Take a look at some composites used in Processing/Java:

Any doubts about my example, just ask!

Just a warning:
Program was bugged a while ago. It was picking the oldest accessed files within a folder!

Correct is -> ( f2.lastModified() - f1.lastModified() )

I was doing the opposite!

Fixed version is from 2.30 and up.

PhiLho

Re: Listing Last 10 Modified Files In Directory

1 month ago

See From several variables to arrays and other entries from the Technical FAQ...

GoToLoop

Re: Listing Last 10 Modified Files In Directory

1 month ago

Updated bug warning:

If a folder have files modified too many days apart, about more than 2 billion milliseconds apart;
the ( int) cast operator would swallow any negative sign from the diff. of lastModified() files within compare().

Version 2.50 and up is fixed now!

GoToLoop

Re: Listing Last 10 Modified Files In Directory

1 month ago

File.lastModified() is a very slow, as any IO operation.
And it was being invoked twice within Comparator.compare() for each Arrays.sort() iteration!

As a way to diminish redundant calls to File.lastModified(),
I had the idea to cache temporarily each result within a WeakHashMap< File, Long> composite.

I believe it got a little better. Dunno for sure.

/** 
 * Display by Last Modified (v3.62)
 * by Kelvin Mead (2013/Aug)
 * mod GoToLoop
 * 
 * http://forum.processing.org/topic/listing-last-10-modified-files-in-directory
 */

import java.io.FilenameFilter;

final static String EXT = ".jpg";

final static FilenameFilter pictsFilter = new FilenameFilter() {
  boolean accept(File dir, String name) {
    return name.toLowerCase().endsWith(EXT);
  }
};

import java.util.Arrays;
import java.util.Comparator;

final static Comparator lastModifiedComparator = new Comparator<File>() {
  int compare(File f1, File f2) {
    //return Long.signum(lastModifiedCache.get(f2) - lastModifiedCache.get(f1));
    return 1 | (int) (lastModifiedCache.get(f2) - lastModifiedCache.get(f1) >> 63);
  }
};

import java.util.Map;
import java.util.WeakHashMap;

final static Map<File, Long> lastModifiedCache = new WeakHashMap(0100);

final static int NUM = 10;
final static PImage[] picts = new PImage[NUM];
final static String[] paths = new String[NUM];

final static float FPS = .5;
final static color BG = 0;
static int cw, ch;

void setup() {
  size(1100, 800);
  frameRate(FPS);
  imageMode(CENTER);
  background(BG);

  cw = width>>1;
  ch = height>>1;
}

void draw() {
  if (picts[0] == null)  return;

  background(BG);

  if (picts[frameCount %= NUM] == null)  frameCount = 0;
  final int idx = frameCount;

  image(picts[idx], cw, ch);
  frame.setTitle("#" + (idx + 1) + ":  " + paths[idx]);
}

void keyPressed() {
  looping = !looping;
}

void mouseClicked() {
  selectFolder("Select a folder to process:", "folderSelected");
}

void folderSelected(File folder) {
  if (folder == null) {
    println("Window was closed or the user hit cancel.");
    return;
  }

  else if (!folder.isDirectory()) {
    println("\"" + folder + "\" is an invalid folder.");
    return;
  }

  final File[] files = folder.listFiles(pictsFilter);
  final int len = files.length;

  if (len == 0) {
    println("No \"" + EXT + "\" pictures found in " + folder + ".");
    return;
  }

  lastModifiedCaching(files);
  Arrays.sort(files, lastModifiedComparator);

  final PImage[] images = picts;
  final String[] names  = paths;
  final int num = min(NUM, len);

  //Arrays.fill(images, null);
  if (num < NUM)  images[num] = null;

  for (int i = num; i-- != 0; images[i] = loadImage(names[i] = files[i].getPath()));

  frameCount = NUM;
}

final static void lastModifiedCaching(File[] archives) {
  //lastModifiedCache.clear();
  System.gc();

  for (File f: archives)  lastModifiedCache.put(f, f.lastModified());
}

Kelvin Me..

Re: Re: Listing Last 10 Modified Files In Directory

1 month ago

just plain amazing! thanks!

after tweaking, i have all my images, in order on may page.

how would i tweak this code to either;

a/ automatically update the images if a new photo is taken

b/ add a time function to check to see if there are any new images

thanks!

GoToLoop

Re: Listing Last 10 Modified Files In Directory

1 month ago

It took a while but here it is. Any doubts about it, just ask:

/** 
 * Display by Last Modified (v4.12)
 * by Kelvin Mead (2013/Aug)
 * mod GoToLoop
 * 
 * http://forum.processing.org/topic/listing-last-10-modified-files-in-directory
 */

import java.io.FilenameFilter;

final static String[] exts = {
  ".gif", ".png", ".jpeg", ".jpg"
};

final static FilenameFilter pictsFilter = new FilenameFilter() {
  boolean accept(File dir, String name) {
    name = name.toLowerCase();
    for (int i = exts.length; i-- != 0;)  if (name.endsWith(exts[i]))  return true;
    return false;
  }
};

import java.util.Arrays;
import java.util.Comparator;

final static Comparator lastModifiedComparator = new Comparator<File>() {
  int compare(File f1, File f2) {
    //return Long.signum(lastModifiedCache.get(f2) - lastModifiedCache.get(f1));
    return 1 | (int) (lastModifiedCache.get(f2) - lastModifiedCache.get(f1) >> 63);
  }
};

import java.util.Map;
import java.util.WeakHashMap;

final static Map<File, Long> lastModifiedCache = new WeakHashMap(0200);

final static int NUM = 10, SLEEP = 1 * 60*1000;
final static PImage[] picts = new PImage[NUM];
final static String[] paths = new String[NUM];

final static float FPS = .5;
final static color BG = 0;

static boolean isBusy, isWatching = true;
static File currDir;
static int  currLen, cw, ch;

void setup() {
  size(1100, 800);
  frameRate(FPS);
  imageMode(CENTER);
  background(BG);

  cw = width>>1;
  ch = height>>1;

  thread("currentFolderSentinel");
}

void draw() {
  if (picts[0] == null)  return;

  background(BG);

  if (picts[frameCount %= NUM] == null)  frameCount = 0;
  final int idx = frameCount;

  image(picts[idx], cw, ch);
  frame.setTitle("#" + (idx + 1) + ":  " + paths[idx]);
}

void keyPressed() {
  looping = !looping;
}

void mouseClicked() {
  selectFolder("Select a folder to process:", "folderSelected");
}

void currentFolderSentinel() {
  while (isWatching) {
    delay(SLEEP);
    if (currDir == null)   continue;

    println("Re-checking \"" + currDir + "\" for new files.");

    final File[] filteredFiles = getFolderContent(currDir);
    final int len = filteredFiles.length;

    if (len != currLen) {
      println("# of files changed from " + currLen + " to " + len + ".");
      println("Updating files now...");

      if (sortLastModified(filteredFiles))  println("Failed!");
      else                                  println("Done!");
    }

    else println("Nothing has changed.");
  }
}

void folderSelected(File folder) {
  if (folder == null)
    println("Window was closed or the user hit cancel.");

  else if (!folder.isDirectory())
    println("\"" + folder + "\" is an invalid folder.");

  else {
    final File[] filteredFiles = getFolderContent(folder);

    for (int i = 0; i != 3; delay(300), ++i)
      if (!sortLastModified(filteredFiles))   return;

    println("Attempts to call sortLastModified() have timed-out!!!");
  }
}

final static File[] getFolderContent(File dir) {
  return dir.listFiles(pictsFilter);
}

boolean sortLastModified(File[] files) {
  synchronized(this) {
    if (isBusy) {
      println("Function sortLastModified() is busy!");
      return true;
    }

    if (files.length == 0) {
      println("No valid picture formats found here.");
      return false;
    }

    isBusy = true;
  }

  currDir = files[0].getParentFile();
  currLen = files.length;

  lastModifiedCaching(files);
  Arrays.sort(files, lastModifiedComparator);

  final PImage[] images = picts;
  final String[] names  = paths;
  final int num = min(NUM, files.length);

  //Arrays.fill(images, null);
  if (num < NUM)  images[num] = null;

  for (int i = num; i-- != 0; images[i] = loadImage(names[i] = files[i].getPath()));
  frameCount = NUM;

  return isBusy = false;
}

final static void lastModifiedCaching(File[] archives) {
  //lastModifiedCache.clear();
  System.gc();

  for (File f: archives)  lastModifiedCache.put(f, f.lastModified());
}

Kelvin Me..

Re: Listing Last 10 Modified Files In Directory

1 month ago

i see a delay(sleep) in here, but part of the sentinel void. does this delay freeze the rest of the program whilst it checks, or will i need to convert this to a millis, lastmillis, currentmillis?

thanks!

Kelvin Me..

Re: Listing Last 10 Modified Files In Directory

1 month ago

i see a delay(sleep) in here, but part of the sentinel void. does this delay freeze the rest of the program whilst it checks, or will i need to convert this to a millis, lastmillis, currentmillis?

thanks!

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