How to determine whether it is a folder in java

package com.tij.io.file;

import java.io.File;

/**
 * 检查File对象是文件还是目录
 * @author guoyoujun
 * @date 2014-3-17
 */
public class CheckDirectoryOrFile {

	/**
	 * java.io.File包含两个方法：isFile(); isDirectory()
	 * <p>isFile();检查改文件对象是否是普通文件,是则return true; 如果文件不存在或者是目录则return false
	 * <p>isDirectory();检查文件对象是否是目录,是则return true; 如果目录不存在或者是普通文件则return false
	 * <p>判断之前应该先exists();
	 * @param args
	 */
	public static void main(String[] args) {
		File file = new File("/Users/GYJ/java1.txt");
		File dir = new File("/Users/GYJ/funshion");
		File notExists = new File("/Users/GYJ/notafile");
		//java1.txt文件存在
		System.out.println("/Users/GYJ/java1.txt is file?" + file.isFile());
		System.out.println("/Users/GYJ/java1.txt is dir?" + file.isDirectory());
		//funshion是目录
		System.out.println("/Users/GYJ/funshion is file?" + dir.isFile());
		System.out.println("/Users/GYJ/funshion is dir?" + dir.isDirectory());
		//notafile不存在
		System.out.println("/Users/GYJ/notafile is file?" + notExists.isFile());
		System.out.println("/Users/GYJ/notafile is dir?" + notExists.isDirectory());
	}

}

out put==========
/Users/GYJ/java1.txt is file?true
/Users/GYJ/java1.txt is dir?false
/Users/GYJ/funshion is file?false
/Users/GYJ/funshion is dir?true
/Users/GYJ/notafile is file?false
/Users/GYJ/notafile is dir?false