java之io之file类的常用操作

package com.westward.io;

import java.io.File;
import java.io.IOException;

public class FileDemo {
public static void main(String[] args) {
File file= new File("d:\\javaio");
@SuppressWarnings("static-access")

File file2= new File("d:"+ file.separator+"javaio\\imooc.txt");
File file3= new File("d:\\javaio\\txt\\read");
System.out.println(file3.exists());
if (!file3.exists()) {
file3.mkdirs();
}
System.out.println(file3.exists());

System.out.println(file2);
System.out.println(file2.getAbsolutePath());
System.out.println(file2.getName());
System.out.println(file2.getParentFile());
System.out.println(file2.getParentFile().getAbsolutePath());
if (file.exists()) {
file.delete();
}
System.out.println(file2.isDirectory());
System.out.println(file2.isFile());
if (!file2.exists()) {
try {
file2.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

package com.westward.io;

import java.io.File;
import java.io.IOException;

public class FileUtil {
public static void listDirectory(File  file) throws IOException{
if (!file.exists()) {
throw new IllegalArgumentException("目录："+ file+ "不存在！");
}
if (!file.isDirectory()) {
throw new IllegalArgumentException(file +"不是目录！");
}
File[] files = file.listFiles();
if (files!= null&& files.length> 0) {
for (File file2 : files) {
if (file2.isDirectory()) {
listDirectory(file2);
}
else {
System.out.println(file2);
}
}
}
}

public static void main(String[] args) throws IOException {
File file= new File("d:\\javaio");
listDirectory(file);
}

}