Stuart McCulloch | 26e7a5a | 2011-10-17 10:31:43 +0000 | [diff] [blame] | 1 | package aQute.lib.deployer.obr; |
| 2 | |
| 3 | import java.io.File; |
| 4 | import java.io.FileNotFoundException; |
| 5 | import java.io.FileOutputStream; |
| 6 | import java.io.IOException; |
| 7 | import java.io.InputStream; |
| 8 | import java.io.OutputStream; |
| 9 | import java.io.UnsupportedEncodingException; |
| 10 | import java.net.URL; |
| 11 | import java.net.URLEncoder; |
| 12 | |
| 13 | import aQute.bnd.service.ResourceHandle; |
| 14 | |
| 15 | public class URLResourceHandle implements ResourceHandle { |
| 16 | |
| 17 | static final String FILE_SCHEME = "file:"; |
| 18 | static final String HTTP_SCHEME = "http:"; |
| 19 | |
| 20 | final File cacheDir; |
| 21 | |
| 22 | // The resolved, absolute URL of the resource |
| 23 | final URL url; |
| 24 | |
| 25 | // The local file, if the resource IS a file, otherwise null. |
| 26 | final File localFile; |
| 27 | |
| 28 | // The cached file copy of the resource, if it is remote and has been downloaded. |
| 29 | final File cachedFile; |
| 30 | |
| 31 | public URLResourceHandle(String url, String baseUrl, final File cacheDir) throws IOException { |
| 32 | this.cacheDir = cacheDir; |
| 33 | if (url.startsWith(FILE_SCHEME)) { |
| 34 | // File URL may be relative or absolute |
| 35 | File file = new File(url.substring(FILE_SCHEME.length())); |
| 36 | if (file.isAbsolute()) { |
| 37 | this.localFile = file; |
| 38 | } else { |
| 39 | if (!baseUrl.startsWith(FILE_SCHEME)) |
| 40 | throw new IllegalArgumentException("Relative file URLs cannot be resolved if the base URL is a non-file URL."); |
| 41 | this.localFile = resolveFile(baseUrl.substring(FILE_SCHEME.length()), file.toString()); |
| 42 | } |
| 43 | this.url = localFile.toURI().toURL(); |
| 44 | if (!localFile.isFile() && !localFile.isDirectory()) |
| 45 | throw new FileNotFoundException("File URL " + this.url + " points at a non-existing file."); |
| 46 | this.cachedFile = null; |
| 47 | } else if (url.startsWith(HTTP_SCHEME)) { |
| 48 | // HTTP URLs must be absolute |
| 49 | this.url = new URL(url); |
| 50 | this.localFile = null; |
| 51 | this.cachedFile = mapRemoteURL(this.url); |
| 52 | } else { |
| 53 | // A path with no scheme means resolve relative to the base URL |
| 54 | if (baseUrl.startsWith(FILE_SCHEME)) { |
| 55 | this.localFile = resolveFile(baseUrl.substring(FILE_SCHEME.length()), url); |
| 56 | this.url = localFile.toURI().toURL(); |
| 57 | this.cachedFile = null; |
| 58 | } else { |
| 59 | URL base = new URL(baseUrl); |
| 60 | this.url = new URL(base, url); |
| 61 | this.localFile = null; |
| 62 | this.cachedFile = mapRemoteURL(this.url); |
| 63 | } |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | File resolveFile(String baseFileName, String fileName) { |
| 68 | File resolved; |
| 69 | |
| 70 | File baseFile = new File(baseFileName); |
| 71 | if (baseFile.isDirectory()) |
| 72 | resolved = new File(baseFile, fileName); |
| 73 | else if (baseFile.isFile()) |
| 74 | resolved = new File(baseFile.getParentFile(), fileName); |
| 75 | else |
| 76 | throw new IllegalArgumentException("Cannot resolve relative to non-existant base file path: " + baseFileName); |
| 77 | |
| 78 | return resolved; |
| 79 | } |
| 80 | |
| 81 | private File mapRemoteURL(URL url) throws UnsupportedEncodingException { |
| 82 | String encoded = URLEncoder.encode(url.toString(), "UTF-8"); |
| 83 | return new File(cacheDir, encoded); |
| 84 | } |
| 85 | |
| 86 | public String getName() { |
| 87 | return url.toString(); |
| 88 | } |
| 89 | |
| 90 | public Location getLocation() { |
| 91 | Location result; |
| 92 | |
| 93 | if (localFile != null) |
| 94 | result = Location.local; |
| 95 | else if (cachedFile.exists()) |
| 96 | result = Location.remote_cached; |
| 97 | else |
| 98 | result = Location.remote; |
| 99 | |
| 100 | return result; |
| 101 | } |
| 102 | |
| 103 | public File request() throws IOException { |
| 104 | if (localFile != null) |
| 105 | return localFile; |
| 106 | if (cachedFile == null) |
| 107 | throw new IllegalStateException("Invalid URLResourceHandle: both local file and cache file are uninitialised."); |
| 108 | |
| 109 | if (!cachedFile.exists()) { |
| 110 | cacheDir.mkdirs(); |
| 111 | downloadToFile(url, cachedFile); |
| 112 | } |
| 113 | |
| 114 | return cachedFile; |
| 115 | } |
| 116 | |
| 117 | private static void downloadToFile(URL url, File file) throws IOException { |
| 118 | InputStream in = null; |
| 119 | OutputStream out = null; |
| 120 | try { |
| 121 | in = url.openStream(); |
| 122 | out = new FileOutputStream(file); |
| 123 | |
| 124 | byte[] buf = new byte[1024]; |
| 125 | for(;;) { |
| 126 | int bytes = in.read(buf, 0, 1024); |
| 127 | if (bytes < 0) break; |
| 128 | out.write(buf, 0, bytes); |
| 129 | } |
| 130 | } finally { |
| 131 | try { if (in != null) in.close(); } catch (IOException e) {}; |
| 132 | try { if (out != null) in.close(); } catch (IOException e) {}; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | } |