URLHandler


1   /*
2    * This file is subject to the license found in LICENCE.TXT in the root directory of the project.
3    * 
4    * #SNAPSHOT#
5    */
6   package fr.jayasoft.ivy.url;
7   
8   import java.io.File  ;
9   import java.io.IOException  ;
10  import java.io.InputStream  ;
11  import java.net.URL  ;
12  
13  import fr.jayasoft.ivy.util.CopyProgressListener;
14  
15  /**
16   * This interface is responsible for handling some URL manipulation
17   * (stream opening, downloading, check reachability, ...). 
18   * 
19   * @author Xavier Hanin
20   *
21   */
22  public interface URLHandler {
23      public static class URLInfo {
24          private long _contentLength;
25          private long _lastModified;
26          private boolean _available;
27          
28          protected URLInfo(boolean available, long contentLength, long lastModified) {
29              _available = available;
30              _contentLength = contentLength;
31              _lastModified = lastModified;
32          }
33          public boolean isReachable() {
34              return _available;
35          }
36          public long getContentLength() {
37              return _contentLength;
38          }
39          public long getLastModified() {
40              return _lastModified;
41          }
42      }
43      public static final URLInfo UNAVAILABLE = new URLInfo(false, 0,0);
44      
45      /**
46       * Please prefer getURLInfo when several infos are needed.
47       * @param url the url to check
48       * @return true if the target is reachable
49       */
50      public boolean isReachable(URL   url);
51      /**
52       * Please prefer getURLInfo when several infos are needed.
53       * @param url the url to check
54       * @return true if the target is reachable
55       */
56      public boolean isReachable(URL   url, int timeout);
57      /**
58       * Returns the length of the target if the given url is reachable, and without
59       * error code in case of http urls.
60       * Please prefer getURLInfo when several infos are needed.
61       * @param url the url to check
62       * @return the length of the target if available, 0 if not reachable
63       */
64      public long getContentLength(URL   url);
65      /**
66       * Returns the length of the target if the given url is reachable, and without
67       * error code in case of http urls.
68       * @param url the url to check
69       * @param timeout the maximum time before considering an url is not reachable
70       *        a timeout of zero indicates no timeout
71       * @return the length of the target if available, 0 if not reachable
72       */
73      public long getContentLength(URL   url, int timeout);
74      
75      /**
76       * Please prefer getURLInfo when several infos are needed.
77       * @param url the url to check
78       * @return last modified timestamp of the given url
79       */
80      public long getLastModified(URL   url);
81      /**
82       * Please prefer getURLInfo when several infos are needed.
83       * @param url the url to check
84       * @return last modified timestamp of the given url
85       */
86      public long getLastModified(URL   url, int timeout);
87      
88      /**
89       * never returns null, return UNAVAILABLE when url is not reachable
90       * @param url
91       * @return
92       */
93      public URLInfo getURLInfo(URL   url);
94      /**
95       * never returns null, return UNAVAILABLE when url is not reachable
96       * @param url
97       * @return
98       */
99      public URLInfo getURLInfo(URL   url, int timeout);
100     
101     public InputStream   openStream(URL   url) throws IOException  ;
102     public void download(URL   src, File   dest, CopyProgressListener l) throws IOException  ;
103 }
104
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