遍历文件

package test.io;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeMap;

public class IteratorDirectory {
	/**
	 * get all folders from given path
	 */
	private static final String PATH = "C:\\workspace1\\test";

	public static List<File> getAllDirectory() {
		List<File> list = new ArrayList<File>();
		File dir = new File(PATH);
		File files[] = dir.listFiles();
		for (File file : files) {
			if (file.isDirectory()) {
				list.add(file);
			}
		}
		return list;
	}
	/**
	 * get last 3 modified folders
	 * @return
	 */
	public static List<File> getLast3Directory() {
		/*get all folders*/
		List<File> files = getAllDirectory();
		List<File> results = new ArrayList<File>();
		/*store all files with sortable map*/
		TreeMap<Long, File> treeMap = new TreeMap<Long, File>();
		for (File file : files) {
			System.out.println("file is dir " + file.getAbsolutePath());
			Long lastModifiedTime = file.lastModified();
			treeMap.put(lastModifiedTime, file);
		}
		while (results.size() < 3) {
			/*get the last modified folder*/
			results.add(treeMap.get(treeMap.lastKey()));
			/*remove from map*/
			treeMap.remove(treeMap.lastKey());
		}
		return results;
	}


	public static List<File> getFilesFromFolder(String folderName){
		List<File> results = new ArrayList<File>();
		List<File> folders = getAllDirectory();
		for(File folder :folders){
			if(folderName.equals(folder.getName())){
				File files[] = folder.listFiles();
				for(File f :files){
					results.add(f);
				}
			}
		}
		return results;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		List<File> files = getFilesFromFolder("dir3");
		for(File file:files){
			System.out.println(file.getName());
		}
	}

}