File类的深度学习(超简易文件管理器)——《Thinking in Java》随笔028

Posted 2020-09-15

  1 //: MakeDirectories.java
  2 package c10;
  3 
  4 import java.io.File;
  5 import java.text.SimpleDateFormat;
  6 import java.util.Date;
  7 
  8 /**
  9 *    @time:         下午7:59:23
 10 *    @date:         2017年4月29日
 11 *    @auther:    skyfffire
 12 *    @version:    v0.1
 13 */
 14 public class MakeDirectories {
 15     private final static String usage 
 16         = "\n\n1.Usage:MakeDirectories path1...\n"
 17         + "\tCreates each path\n\n"
 18         + "2.Usage:MakeDirectories -d path1...\n"
 19         + "\tDeletes each path\n\n"
 20         + "3.Usage:MakeDirectories -r path1 path2...\n"
 21         + "\tRenames from path1 to path2\n\n";
 22     
 23     /**
 24      * 使用方法
 25      */
 26     private static void usage() {
 27         System.out.println(usage);
 28         System.exit(1);
 29     }
 30     
 31     /**
 32      * 显示一个path的详细信息
 33      * 
 34      * @param f 需要显示的path
 35      */
 36     private static void fileData(File f) {
 37         System.out.println("\n\nAbsolute path:" + f.getAbsolutePath());
 38         System.out.println("Can read:" + f.canRead());
 39         System.out.println("Can Write:" + f.canWrite());
 40         System.out.println("getName:" + f.getName());
 41         System.out.println("getParent:" + f.getParent());
 42         System.out.println("getPath:" + f.getPath());
 43         System.out.println("length:" + f.length());        
 44         System.out.println("lastModified:" 
 45         + new SimpleDateFormat("yy-MM-dd").
 46         format(new Date(f.lastModified())));
 47         
 48         if (f.isFile()) {
 49             System.out.println("It‘s a file.");
 50         } else if (f.isDirectory()) {
 51             System.out.println("It‘s a directory.");
 52         }
 53         
 54         System.out.println("\n\n");
 55     }
 56     
 57     /**
 58      * 打印当前目录下的所有path
 59      */
 60     private static void printPath() {
 61         System.out.println();
 62         
 63         File point = new File(".");
 64         
 65         String[] path = point.list();
 66         
 67         for (String nowString : path) {
 68             System.out.println(nowString);
 69         }
 70         
 71         System.out.println();
 72     }
 73     
 74     public static void main(String[] args) {
 75         printPath();
 76         
 77         if (args.length < 1) {
 78             usage();
 79         }
 80         
 81         // 更新path名字命令
 82         if (args[0].equals("-r")) {
 83             if (args.length != 3) {
 84                 usage();
 85             } else {
 86                 File old = new File(args[1]);
 87                 File rname = new File(args[2]);
 88                 
 89                 if (old.exists() && !rname.exists()) {
 90                     // 更新文件名
 91                     old.renameTo(rname);
 92                 } else {
 93                     System.out.println("rename error: "
 94                             + old.getName() + " to " + rname.getName());
 95                 }
 96                 
 97                 // 打印信息
 98                 fileData(old);
 99                 fileData(rname);
100             }
101         } // 执行删除命令
102         else if (args[0].equals("-d")) {
103             for (int count = 1; count < args.length; count++) {
104                 File f = new File(args[count]);
105                 
106                 // 判断f是否存在
107                 if (f.exists()) {
108                     System.out.println(f + " exists");
109                     
110                     System.out.println("deleting..." + f);
111                     f.delete();
112 
113                     fileData(f);
114                 } else {
115                     System.out.println(f + " path is not found.");
116                 }
117             }
118         } // 执行创建命令
119         else {
120             for (int count = 0; count < args.length; count++) {
121                 File f = new File(args[count]);
122                 
123                 f.mkdirs();
124                 // f.mkdir()与f.mkdirs()的区别在于
125                 // mkdir不能在不存在的目录创建文件夹
126                 
127                 System.out.println("created " + f);
128 
129                 fileData(f);
130             }
131         }
132         
133         printPath();
134     }
135 }
136 
137 ///:~

 

优化了原书中某些不合理的地方。运行时将参数列表置于java xxx 之后即可。