Uncompress


1   /*
2    * Copyright (c) 2001 Matthew Feldt. All rights reserved.
3    *
4    * Redistribution and use in source and binary forms, with or without
5    * modification, are permitted provided the copyright notice above is
6    * retained.
7    *
8    * THIS SOFTWARE IS PROVIDED ''AS IS'' AND WITHOUT ANY EXPRESSED OR
9    * IMPLIED WARRANTIES.
10   */
11  
12  /**
13   * DirectoryList.java
14   *
15   * Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
16   * Exercise 3-6:
17   * Write a program named Uncompress that uncompresses files and directories
18   * compressed by the Compress example in this chapter.
19   *
20   * @author Matthew Feldt <matthew@feldt.com>
21   * @version 1.0, 02/08/2001 22:08
22   */
23  
24  /*
25   * Some lines are changed for this application
26   */
27  package org.openuss.utility;
28  
29  import java.io.*;
30  
31  import java.util.zip.*;
32  
33  
34  public class Uncompress {
35      /**
36       * Use gunzip the string.
37       */
38      public static void gunzipFile(String   from, String   to)
39                             throws IllegalArgumentException  , IOException {
40          byte[] buffer = new byte[4096];
41          int bytes_read;
42  
43          // check input file
44          File fin = new File(from);
45  
46          if (!fin.exists()) {
47              throw new IllegalArgumentException  (from + " does not exist.");
48          }
49  
50          if (!fin.canRead()) {
51              throw new IllegalArgumentException  (from + " read protected.");
52          }
53  
54          // GZIPInputStream in = new GZIPInputStream(fileInputStream);
55          GZIPInputStream in = new GZIPInputStream(new FileInputStream(from));
56  
57          File fout = new File(to);
58  
59          if (fout.exists()) {
60              // don't overwrite existing files
61              throw new IllegalArgumentException  ("File '" + to + 
62                                                 "' already exisits.");
63          }
64  
65          FileOutputStream out = new FileOutputStream(to);
66  
67          while ((bytes_read = in.read(buffer)) != -1)
68  
69              // write file
70              out.write(buffer, 0, bytes_read);
71  
72          in.close();
73          out.close();
74      }
75  
76      /**
77       * Use unzip the string.
78       */
79      public static void unzipFile(String   from, String   to)
80                            throws IllegalArgumentException  , IOException {
81          byte[] buffer = new byte[4096];
82          int bytes_read;
83  
84          // check input file
85          File fin = new File(from);
86  
87          if (!fin.exists()) {
88              throw new IllegalArgumentException  (from + " does not exist.");
89          }
90  
91          if (!fin.canRead()) {
92              throw new IllegalArgumentException  (from + " read protected.");
93          }
94  
95          ZipInputStream in = new ZipInputStream(new FileInputStream(from));
96          ZipEntry entry;
97          FileOutputStream out;
98  
99          while ((entry = in.getNextEntry()) != null) {
100             String   toName = to + File.separator + entry.getName();
101             File fout = new File(toName);
102 
103             /*
104              * This must be removed
105              *
106                                                        
107             if (fout.exists()) { // don't overwrite existing files and continue
108               System.err.println("File '" + toName + "' already exisits.");
109               continue;
110             }
111                                                 
112             * This must be insert
113             */
114             if (entry.isDirectory()) {
115                 // create directory for directory entries
116                 if (!fout.mkdirs()) {
117                     System.err.println("Unable to create directory: " + 
118                                        toName);
119                 }
120             } else {
121                 // write file
122                 out = new FileOutputStream(toName);
123 
124                 while ((bytes_read = in.read(buffer)) != -1)
125                     out.write(buffer, 0, bytes_read);
126 
127                 out.close();
128             }
129 
130             // System.out.println(toName);
131         }
132 
133         in.close();
134     }
135 }
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