Copy folder based on latest date

[ayonsoni]

Hi,

Can anybody send me the java code to do following:

- A directory containing sub-folders with different name and date
- To copy the folder having the most recent date from the directory.

Thanks in advance.

Ayon

[helloworld922]

Please show us your thoughts/code attempts to solve the problem and we will help you

You will probably want to use the File Class.

[ayonsoni]

Well , I tried using File class, which has a method called file.lastmodified(), this returns long value of the time.
Using this I am not able to sort the latest folder created. Can you please suggest me , how to sort based on long value?

[helloworld922]

The long value returned is the number of milliseconds from a pre-determined time (I believe it's Jan. 1, 1960, but don't quote me on this, and it doesn't really matter for sorting). So, the most recently modified file is the file that has the larges long value returned, and the oldest has the smallest value.

If you need to convert this long value to a Date object, I think there's a method inside the Date class, or possibly one of the Calendar classes (the Java Date/Time representation is a little lacking here)

[dlorde]

If you need to convert this long value to a Date object, I think there's a method inside the Date class...

There's both a constructor and a setTime(..) method that take a long as milliseconds.

[Json]

Basically use the File class and create an instance which points to your base directory.

Use file.listFiles() get all the files in the base directory.
Use a comparator to sort the array by lastModified.
Grab the newest file and add it to your list.
Get all directories in the base directory and do the same for each directory.

As a reply to your question on sorting this is what you could do.

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

Assuming files is an array of File objects. This would put the last edited file/directory at index zero.

// Json

[Time]

Somthing like?

	private static File getRecent(String directory) {
		File file = null;
		for(String x : new File(directory).list()) {
			File inQuestion = new File(directory + x);
			if(file == null) {
				file = inQuestion;
				continue;
			}
			if(inQuestion.lastModified() < file.lastModified()) {
				file = inQuestion;
			}
		}
		return file;
	}

It returns the most recently created file in the directory,

[Json]

Hello Time, would that not also return you a directory if the latest modified file in the directory was actually another directory?

// Json

[Time]

Hello Time, would that not also return you a directory if the latest modified file in the directory was actually another directory?

// Json

Just do, if(!inQuestion.isDirectory())

[Json]

or if(inQuestion.isFile()) perhaps

// Json

[ayonsoni]

Thanks , I have tried this and somehow gotthis working.

Thanks again for your help