java get list of files in directory code example

Example 1: how to get all the names of the files in a folder in java?

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());
    }
}

Example 2: java list all non directory files in the directory

public class Pathnames {

    public static void main(String[] args) {
        // Creates an array in which we will store the names of files and directories
        String[] pathnames;

        // Creates a new File instance by converting the given pathname string
        // into an abstract pathname
        File f = new File("D:/Programming");

        // Populates the array with names of files and directories
        pathnames = f.list();

        // For each pathname in the pathnames array
        for (String pathname : pathnames) {
            // Print the names of files and directories
            System.out.println(pathname);
        }
    }
}

Example 3: java get all files in directory

public static List<String> mapFolder(String path, boolean includeEmptyFolders) {
    	List<String> map = new ArrayList<String>();
    	List<String> unmappedDirs = new ArrayList<String>();
    	File[] items = new File(path).listFiles();

    	if (!path.substring(path.length() - 1).equals("/")) {
    		path += "/";
    	}
    		
    	if (items != null) {
	    	for (File item : items) {
	    		if (item.isFile())
	    				map.add(path+item.getName());
	    		else
	    			unmappedDirs.add(path+item.getName());
	    	}
	    	
	    	if (!unmappedDirs.isEmpty()) {
	    		for (String folder : unmappedDirs) {
	    			List<String> temp = mapFolder(folder, includeEmptyFolders);
	    			if (!temp.isEmpty()) {
	    				for (String item : temp)
	    					map.add(item);
    				} else if (includeEmptyFolders == true)
    					map.add(folder+"/");
	    		}
	    	}
    	}
    	return map;
    }

Example 4: java list files in directory

File f = new File("D:/Programming");

// This filter will only include files ending with .py
FilenameFilter filter = new FilenameFilter() {
        @Override
        public boolean accept(File f, String name) {
            return name.endsWith(".py");
        }
    };

// This is how to apply the filter
String [] pathnames = f.list(filter);