| 1 | /** |
| 2 | * BSD-style license; for more info see http://xradar.sourceforge.net/license.html |
| 3 | */ |
| 4 | package org.sourceforge.xradar.util; |
| 5 | |
| 6 | import java.io.BufferedInputStream; |
| 7 | import java.io.BufferedWriter; |
| 8 | import java.io.File; |
| 9 | import java.io.FileInputStream; |
| 10 | import java.io.FileNotFoundException; |
| 11 | import java.io.FileOutputStream; |
| 12 | import java.io.FileWriter; |
| 13 | import java.io.IOException; |
| 14 | import java.io.InputStream; |
| 15 | import java.io.OutputStream; |
| 16 | import java.io.Writer; |
| 17 | import java.net.MalformedURLException; |
| 18 | import java.net.URL; |
| 19 | |
| 20 | import javax.xml.transform.stream.StreamResult; |
| 21 | |
| 22 | import org.sourceforge.xradar.XRadarException; |
| 23 | |
| 24 | /** |
| 25 | * <p>An utility class to regroup every common functions |
| 26 | * about stream handling.</p> |
| 27 | * |
| 28 | * @author rpelisse, belaran@gmail.com |
| 29 | * |
| 30 | */ |
| 31 | //TODO: Maybe a good candidate to create java5 static imports |
| 32 | public final class StreamUtils { |
| 33 | |
| 34 | private static final int EOF = -1; |
| 35 | // Should not be instantiated |
| 36 | private StreamUtils() {} |
| 37 | |
| 38 | /** |
| 39 | * <p>Handy method to easily copy from one inputstream to a file |
| 40 | * <code> |
| 41 | * copy(new File("source.dat"), new File("destination.dat")); |
| 42 | * </code> |
| 43 | * </p> |
| 44 | * @param src, inputstream <u>to copy</u>. |
| 45 | * @param dst, outstream. |
| 46 | * @throws Exception |
| 47 | */ |
| 48 | public static void copy(InputStream in, OutputStream out) throws XRadarException |
| 49 | { |
| 50 | try { |
| 51 | StreamUtils.copyStreamToStream(in, out); |
| 52 | } catch (FileNotFoundException e) { |
| 53 | new XRadarException("Failed to copy",e); |
| 54 | } catch (Exception e) { |
| 55 | new XRadarException("Failed to copy",e); |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | /** |
| 60 | * <p>Commodity method to copy a file into an other file, based only with |
| 61 | * their filename. Also, wraps any exception around an XRadarException.</p> |
| 62 | * |
| 63 | * @param fileIn |
| 64 | * @param fileOut |
| 65 | * @throws XRadarException |
| 66 | */ |
| 67 | public static void copyFileToFile(String fileIn, String fileOut) throws XRadarException |
| 68 | { |
| 69 | |
| 70 | try { |
| 71 | StreamUtils.copy(new FileInputStream(fileIn), new FileOutputStream(fileOut)); |
| 72 | } catch (FileNotFoundException e) { |
| 73 | new XRadarException("Failed to copy",e); |
| 74 | } catch (Exception e) { |
| 75 | new XRadarException("Failed to copy",e); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * <p>Commodity method to copy an inputStream into an Outputstream</p> |
| 81 | * @param in |
| 82 | * @param out |
| 83 | * @throws IOException |
| 84 | */ |
| 85 | public static void copyStreamToStream(InputStream in, OutputStream out) throws IOException |
| 86 | { |
| 87 | // copying data, byte to byte. |
| 88 | byte[] buf = new byte[1024]; |
| 89 | int len; |
| 90 | while ( ( len = in.read(buf) ) > 0 ) //NOPMD |
| 91 | out.write(buf, 0, len); |
| 92 | // closing both resources |
| 93 | in.close(); |
| 94 | out.close(); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Commodity method |
| 99 | */ |
| 100 | public static StreamResult createOuput(Writer writer) { |
| 101 | return new StreamResult(new BufferedWriter(writer)); |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * <p>Commodity method to construct a simple FileWriter with its filename.</p> |
| 106 | * |
| 107 | * @param output |
| 108 | * @return |
| 109 | * @throws XRadarException |
| 110 | */ |
| 111 | public static Writer createFileWriter(String output) throws XRadarException { |
| 112 | Writer writer = null; |
| 113 | try { |
| 114 | writer = new FileWriter(new File(output)); |
| 115 | } catch (IOException e) { |
| 116 | throw new XRadarException("Can't create file " + output,e); |
| 117 | } |
| 118 | return writer; |
| 119 | } |
| 120 | |
| 121 | /** |
| 122 | * Get an InputStream from a path filename. |
| 123 | * @throws XRadarException |
| 124 | */ |
| 125 | public static InputStream retrieveFileContentAsStream(String filename) throws XRadarException { |
| 126 | try |
| 127 | { |
| 128 | //FIXME: move to calling this following line to any calling code |
| 129 | //logger.log(Level.FINE,"Retrieving filename from URL:" + filename); |
| 130 | return new BufferedInputStream(new URL(filename).openStream()); |
| 131 | } |
| 132 | catch (MalformedURLException e) { |
| 133 | throw new XRadarException("Error while retrieving filename from URL" + filename,e); |
| 134 | } |
| 135 | catch (IOException e) { |
| 136 | throw new XRadarException("Error while retrieving filename from URL" + filename,e); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Get an InputStream from a file, on the file system. This method does not |
| 142 | * use the XRadar URL resolver, and will fail with URL. |
| 143 | * |
| 144 | * @param filename |
| 145 | * @return |
| 146 | * @throws XRadarException |
| 147 | */ |
| 148 | public static InputStream readFile(String filename) throws XRadarException |
| 149 | { |
| 150 | try |
| 151 | { |
| 152 | return new FileInputStream(new File(filename)); |
| 153 | } |
| 154 | catch (FileNotFoundException e) |
| 155 | { |
| 156 | throw new XRadarException("Unable to read file : " + filename,e); |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * <p>Utility method to create an InputStream, based on a filename.</p> |
| 162 | * @param filename |
| 163 | * @return |
| 164 | * @throws XRadarException |
| 165 | */ |
| 166 | public static InputStream fromFilenameToInputStream(String filename) throws XRadarException { |
| 167 | try |
| 168 | { |
| 169 | return new FileInputStream(filename); |
| 170 | } |
| 171 | catch (FileNotFoundException e) |
| 172 | { |
| 173 | new XRadarException("Can't convert file to stream",e); |
| 174 | } |
| 175 | return null; |
| 176 | } |
| 177 | |
| 178 | public static OutputStream createOutputStream(String filename) throws XRadarException |
| 179 | { |
| 180 | try { |
| 181 | return new FileOutputStream(new File(filename)); |
| 182 | } catch (FileNotFoundException e) { |
| 183 | throw new XRadarException("Can't create file " + filename,e); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | public static InputStream returnStream(InputStream stream,String filename) { |
| 188 | if ( stream.markSupported() ) { |
| 189 | stream.mark(1); |
| 190 | try { |
| 191 | if ( stream.read() == EOF ) |
| 192 | stream = StreamUtils.rebuildFileInputStream(stream, filename); |
| 193 | else |
| 194 | stream.reset(); |
| 195 | } |
| 196 | catch (IOException error ) { // this should never happens ! |
| 197 | stream = StreamUtils.rebuildFileInputStream(stream, filename); |
| 198 | } |
| 199 | } |
| 200 | else |
| 201 | { |
| 202 | try { |
| 203 | stream.available(); // throw an exception if stream invalid so ... |
| 204 | } |
| 205 | catch (IOException e) { // ... we created again the stream |
| 206 | stream = StreamUtils.rebuildFileInputStream(stream, filename); |
| 207 | } |
| 208 | } |
| 209 | return stream; |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * <p>Rather weird method wrote in order to rebuild a stream that can't be |
| 214 | * "rewinded". Please do not use this method, it is a hack, doomed to |
| 215 | * disappear at some point.</p> |
| 216 | * @param stream |
| 217 | * @param filename |
| 218 | * @return |
| 219 | */ |
| 220 | public static InputStream rebuildFileInputStream(InputStream stream,String filename) { |
| 221 | try { |
| 222 | stream = new FileInputStream(filename); |
| 223 | } |
| 224 | catch (FileNotFoundException fileNotFoundException) { |
| 225 | // well, this should never happens... :) |
| 226 | stream = null; |
| 227 | } |
| 228 | return stream; |
| 229 | } |
| 230 | |
| 231 | public static void closeStream(InputStream stream) throws XRadarException { |
| 232 | if ( stream != null ) { |
| 233 | try { |
| 234 | stream.close(); |
| 235 | } catch (IOException e) { |
| 236 | new XRadarException(e); |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | } |