Java tutorial
/* The contents of this file are subject to the license and copyright terms * detailed in the license directory at the root of the source tree (also * available online at http://fedora-commons.org/license/). */ package fedora.utilities; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import fedora.common.FaultException; /** * Base-64 utility methods. */ public abstract class Base64 { /** * Encodes bytes to base 64, returning bytes. * * @param in bytes to encode * @return encoded bytes */ public static byte[] encode(byte[] in) { return org.apache.commons.codec.binary.Base64.encodeBase64(in); } /** * Encodes an input stream to base64, returning bytes. * <p> * The stream is guaranteed to be closed when this method returns, whether * successful or not. * * @param in stream to encode * @param encoded bytes, or null if there's an error reading the stream */ public static byte[] encode(InputStream in) { try { ByteArrayOutputStream out = new ByteArrayOutputStream(); byte[] buf = new byte[4096]; int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } return encode(out.toByteArray()); } catch (IOException e) { return null; } finally { try { in.close(); } catch (IOException e) { throw new FaultException(e); } } } /** * Encodes bytes to base 64, returning a string. * * @param in bytes to encode * @return encoded string */ public static String encodeToString(byte[] in) { return getString(encode(in)); } /** * Encodes an input stream to base64, returning a string. * <p> * The stream is guaranteed to be closed when this method returns, whether * successful or not. * * @param in stream to encode * @param encoded string, or null if there's an error reading the stream */ public static String encodeToString(InputStream in) { return getString(encode(in)); } /** * Decodes bytes from base 64, returning bytes. * * @param in bytes to decode * @return decoded bytes */ public static byte[] decode(byte[] in) { return org.apache.commons.codec.binary.Base64.decodeBase64(in); } /** * Decodes a string from base 64, returning bytes. * * @param in string to decode * @return decoded bytes */ public static byte[] decode(String in) { return decode(getBytes(in)); } /** * Decodes bytes from base 64, returning a string. * * @param in bytes to decode * @return decoded string */ public static String decodeToString(byte[] in) { return getString(decode(in)); } private static String getString(byte[] bytes) { try { if (bytes == null) return null; return new String(bytes, "UTF-8"); } catch (UnsupportedEncodingException wontHappen) { throw new FaultException(wontHappen); } } private static byte[] getBytes(String string) { try { if (string == null) return null; return string.getBytes("UTF-8"); } catch (UnsupportedEncodingException wontHappen) { throw new FaultException(wontHappen); } } }