import java.util.*;
import java.io.*;public class Hello
{public static void main(String[] args) throws Exception{File f = new File("C:" + File.separator + "D" + File.separator + "code" + File.separator + "resource" + File.separator + "test.txt");if(f.exists()){f.delete();}else{f.createNewFile();}}
}

import java.util.*;
import java.io.*;public class Hello
{public static void main(String[] args) throws Exception{File f = new File("C:" + File.separator + "D" + File.separator + "hello" + File.separator + "abc" + File.separator + "test.txt");String parentFolderPath = f.getParent();File parentFolder = f.getParentFile();System.out.println("文件的父路径是:" + parentFolderPath);if(!parentFolder.exists()){//创建文件的所有父文件夹System.out.println("该父路径不存在,现在为其创建一个。");parentFolder.mkdirs();}else{System.out.println("该父路径已经存在.");}if(f.exists())//判断文件是否存在{//若存在,则删除
            f.delete();}else{//若不存在,则创建
            f.createNewFile();}}
}

import java.util.*;
import java.io.*;
import java.math.*;
import java.text.*;public class Hello
{public static void main(String[] args) throws Exception{File f = new File("C:" + File.separator + "F"  + File.separator + "JAVA" + File.separator + "JavaWeb" + File.separator + "java_ee_javadocs.zip");long fileLength = f.length();long lastModifiedTime = f.lastModified();System.out.println("文件大小:" + new BigDecimal(fileLength).divide(new BigDecimal(1024*1024),2,RoundingMode.HALF_DOWN ) + "M");System.out.println("最后修改时间:" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS").format(lastModifiedTime));System.out.println("是否是文件:" + f.isFile());System.out.println("是否是文件夹:" + f.isDirectory());}
}

import java.util.*;
import java.io.*;
import java.math.*;
import java.text.*;public class Hello
{public static void main(String[] args) throws Exception{File f = new File("C:" + File.separator + "F"  + File.separator + "JAVA" + File.separator + "JavaWeb");if(f.isDirectory()){File[] files = f.listFiles();for(File item : files){System.out.println(item.getName());}System.out.println("===================");String[] filesName = f.list();for(String item : filesName){System.out.println(item);}} }
}