diff options
Diffstat (limited to 'common/src/at/gv/egovernment/moa/util/StreamUtils.java')
-rw-r--r-- | common/src/at/gv/egovernment/moa/util/StreamUtils.java | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/common/src/at/gv/egovernment/moa/util/StreamUtils.java b/common/src/at/gv/egovernment/moa/util/StreamUtils.java new file mode 100644 index 000000000..88db24504 --- /dev/null +++ b/common/src/at/gv/egovernment/moa/util/StreamUtils.java @@ -0,0 +1,116 @@ +package at.gv.egovernment.moa.util; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; + +/** + * Utility methods for streams. + * + * @author Patrick Peck + * @version $Id$ + */ +public class StreamUtils { + + /** + * Compare the contents of two <code>InputStream</code>s. + * + * @param is1 The 1st <code>InputStream</code> to compare. + * @param is2 The 2nd <code>InputStream</code> to compare. + * @return boolean <code>true</code>, if both streams contain the exactly the + * same content, <code>false</code> otherwise. + * @throws IOException An error occurred reading one of the streams. + */ + public static boolean compareStreams(InputStream is1, InputStream is2) + throws IOException { + + byte[] buf1 = new byte[256]; + byte[] buf2 = new byte[256]; + int length1; + int length2; + + try { + while (true) { + length1 = is1.read(buf1); + length2 = is2.read(buf2); + + if (length1 != length2) { + return false; + } + if (length1 <= 0) { + return true; + } + if (!compareBytes(buf1, buf2, length1)) { + return false; + } + } + } catch (IOException e) { + throw e; + } finally { + // close both streams + try { + is1.close(); + is2.close(); + } catch (IOException e) { + // ignore this + } + } + } + + /** + * Compare two byte arrays, up to a given maximum length. + * + * @param b1 1st byte array to compare. + * @param b2 2nd byte array to compare. + * @param length The maximum number of bytes to compare. + * @return <code>true</code>, if the byte arrays are equal, <code>false</code> + * otherwise. + */ + private static boolean compareBytes(byte[] b1, byte[] b2, int length) { + if (b1.length != b2.length) { + return false; + } + + for (int i = 0; i < b1.length && i < length; i++) { + if (b1[i] != b2[i]) { + return false; + } + } + + return true; + } + + /** + * Reads a byte array from a stream. + * @param in The <code>InputStream</code> to read. + * @return The bytes contained in the given <code>InputStream</code>. + * @throws IOException on any exception thrown + */ + public static byte[] readStream(InputStream in) throws IOException { + ByteArrayOutputStream out = new ByteArrayOutputStream(); + int b; + while ((b = in.read()) >= 0) + out.write(b); + in.close(); + return out.toByteArray(); + } + + /** + * Reads a <code>String</code> from a stream, using given encoding. + * @param in The <code>InputStream</code> to read. + * @param encoding The character encoding to use for converting the bytes + * of the <code>InputStream</code> into a <code>String</code>. + * @return The content of the given <code>InputStream</code> converted into + * a <code>String</code>. + * @throws IOException on any exception thrown + */ + public static String readStream(InputStream in, String encoding) throws IOException { + ByteArrayOutputStream out = new ByteArrayOutputStream(); + int b; + while ((b = in.read()) >= 0) + out.write(b); + in.close(); + return out.toString(encoding); + } + +} |