java的file

public class Hello { public static void main(String[] args) throws Exception {  // TODO Auto-generated method stub  System.out.println("File类只用于表示文件或者目录的信息，不能对文件或目录进行访问");  System.out.println("---------目录属性--------------");  File mulu = new File("G:/ceshifile/hello");  System.out.println(mulu.length());  System.out.println(mulu.lastModified());  System.out.println(mulu.getName());  System.out.println(mulu.getPath());  System.out.println(mulu.exists());  System.out.println(mulu.isFile());  System.out.println(mulu.isDirectory());  System.out.println(mulu.canRead());  System.out.println(mulu.canWrite());  System.out.println("--------文件属性---------------");  File wenjian = new File("G:/ceshifile/hello.txt");  System.out.println(wenjian.length());  System.out.println(wenjian.lastModified());  System.out.println(wenjian.getName());  System.out.println(wenjian.getPath());  System.out.println(wenjian.exists());  System.out.println(wenjian.isFile());  System.out.println(wenjian.isDirectory());  System.out.println(wenjian.canRead());  System.out.println(wenjian.canWrite());  System.out.println("----------创建目录-------------");  File xinjianmulu = new File("demo");  if (!xinjianmulu.exists()) {   xinjianmulu.mkdir();// 新建文件夹  }  System.out.println(xinjianmulu.exists());  System.out.println(xinjianmulu.getPath());  System.out.println(xinjianmulu.getAbsolutePath());  System.out.println(xinjianmulu.getCanonicalPath());  System.out.println("---------创建文件--------------");  File xinjianwenjian = new File(xinjianmulu, "hello.txt");  if (!xinjianwenjian.exists()) {   xinjianwenjian.createNewFile();// 新建文件  }  System.out.println(xinjianwenjian.getPath());  System.out.println(xinjianwenjian.getCanonicalPath());  System.out.println("----------------------------------");  File mulu2 = new File(xinjianmulu,"demo2");  if (!mulu2.exists()) {   mulu2.mkdir();// 新建文件夹  }  File wenjian2 = new File(mulu2, "hello2.txt");  if (!wenjian2.exists()) {   wenjian2.createNewFile();// 新建文件     }  System.out.println("---------创建文件，连带创建目录--------------");  File mulu3 = new File(new File(xinjianmulu,"demo3"),"demo3s");  if (!mulu3.exists()) {   mulu3.mkdirs();// 新建文件夹包同时新建父文件夹  }  System.out.println("-----------------------"); }}