File类基本示例

                  以上各方法实现的测试代码如下：

                            import java.io.File;

/**

 * File类使用示例

 */

public class FileDemo {

         public static void main(String[] args) {

                   //创建File对象

                   File f1 = new File("d:\\test");

                   File f2 = new File("1.txt");

                   File f3 = new File("e:\\file.txt");

                   File f4 = new File("d:\\","1.txt");

                   //创建文件

                   try{

                            boolean b = f3.createNewFile();

                   }catch(Exception e){

                            e.printStackTrace();

                   }

                   //判断文件是否存在

                   System.out.println(f4.exists());

                   //获得文件的绝对路径

                   System.out.println(f3.getAbsolutePath());

                   //获得文件名

                   System.out.println(f3.getName());

                   //获得父路径

                   System.out.println(f3.getParent());

                   //判断是否是目录

                   System.out.println(f1.isDirectory());

                   //判断是否是文件

                   System.out.println(f3.isFile());

                   //获得文件长度

                   System.out.println(f3.length());

                   //获得当前文件夹下所有文件和文件夹名称

                   String[] s = f1.list();

                   for(int i = 0;i < s.length;i++){

                            System.out.println(s[i]);

                   }

                   //获得文件对象

                   File[] f5 = f1.listFiles();

                   for(int i = 0;i < f5.length;i++){

                            System.out.println(f5[i]);

                   }

                   //创建文件夹

                   File f6 = new File("e:\\test\\abc");

                   boolean b1 = f6.mkdir();

                   System.out.println(b1);

                   b1 = f6.mkdirs();

                   System.out.println(b1);

                   //修改文件名

                   File f7 = new File("e:\\a.txt");

                   boolean b2 = f3.renameTo(f7);

                   System.out.println(b2);

                   //设置文件为只读

                   f7.setReadOnly();            

         }

}