I need to create a list with all names of the files in a folder.
For example, i开发者_运维问答f I have:
000.jpg
012.jpg
013.jpg
I want to store them in a ArrayList
with [000,012,013]
as values.
What's the best way to do it in Java ?
PS: I'm on Mac OS X
You could do it like that:
File folder = new File("your/path");
File[] listOfFiles = folder.listFiles();
for (int i = 0; i < listOfFiles.length; i++) {
if (listOfFiles[i].isFile()) {
System.out.println("File " + listOfFiles[i].getName());
} else if (listOfFiles[i].isDirectory()) {
System.out.println("Directory " + listOfFiles[i].getName());
}
}
Do you want to only get JPEG files or all files?
Create a File
object, passing the directory path to the constructor. Use the listFiles()
to retrieve an array of File
objects for each file in the directory, and then call the getName()
method to get the filename.
List<String> results = new ArrayList<String>();
File[] files = new File("/path/to/the/directory").listFiles();
//If this pathname does not denote a directory, then listFiles() returns null.
for (File file : files) {
if (file.isFile()) {
results.add(file.getName());
}
}
Here's how to look in the documentation.
First, you're dealing with IO, so look in the java.io
package.
There are two classes that look interesting: FileFilter and FileNameFilter. When I clicked on the first, it showed me that there was a a listFiles()
method in the File class. And the documentation for that method says:
Returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname.
Scrolling up in the File
JavaDoc, I see the constructors. And that's really all I need to be able to create a File
instance and call listFiles()
on it. Scrolling still further, I can see some information about how files are named in different operating systems.
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