Java tutorial
/* * [This class was "borrowed" from the Apache Axis2 project; the * original class name was "org.apache.axiom.om.util.Base64". * See the license belowe for further informations. ] * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package it.unipmn.di.dcs.common.conversion; import java.io.IOException; import java.io.OutputStream; import java.io.Writer; /** * Base64 encoder/decoder class. * * @deprecated As of release 1.6, replaced by * {@link org.apache.commons.codec.binary.Base64} * * @see org.apache.axiom.om.util.Base64 * @see org.apache.commons.codec.binary.Base64 */ @Deprecated public class Base64 { private static final char[] S_BASE64CHAR = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; private static final char S_BASE64PAD = '='; private static final byte[] S_DECODETABLE = new byte[128]; static { for (int i = 0; i < S_DECODETABLE.length; i++) S_DECODETABLE[i] = Byte.MAX_VALUE; // 127 for (int i = 0; i < S_BASE64CHAR.length; i++) // 0 to 63 S_DECODETABLE[S_BASE64CHAR[i]] = (byte) i; } private static int Decode0(char[] ibuf, byte[] obuf, int wp) { int outlen = 3; if (ibuf[3] == S_BASE64PAD) outlen = 2; if (ibuf[2] == S_BASE64PAD) outlen = 1; int b0 = S_DECODETABLE[ibuf[0]]; int b1 = S_DECODETABLE[ibuf[1]]; int b2 = S_DECODETABLE[ibuf[2]]; int b3 = S_DECODETABLE[ibuf[3]]; switch (outlen) { case 1: obuf[wp] = (byte) (b0 << 2 & 0xfc | b1 >> 4 & 0x3); return 1; case 2: obuf[wp++] = (byte) (b0 << 2 & 0xfc | b1 >> 4 & 0x3); obuf[wp] = (byte) (b1 << 4 & 0xf0 | b2 >> 2 & 0xf); return 2; case 3: obuf[wp++] = (byte) (b0 << 2 & 0xfc | b1 >> 4 & 0x3); obuf[wp++] = (byte) (b1 << 4 & 0xf0 | b2 >> 2 & 0xf); obuf[wp] = (byte) (b2 << 6 & 0xc0 | b3 & 0x3f); return 3; default: throw new RuntimeException("internalError00"); } } /** * Decode a Base64 data. * * Original method name is <em>decode</em>. */ public static byte[] Decode(char[] data, int off, int len) { char[] ibuf = new char[4]; int ibufcount = 0; byte[] obuf = new byte[len / 4 * 3 + 3]; int obufcount = 0; for (int i = off; i < off + len; i++) { char ch = data[i]; if (ch == S_BASE64PAD || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) { ibuf[ibufcount++] = ch; if (ibufcount == ibuf.length) { ibufcount = 0; obufcount += Decode0(ibuf, obuf, obufcount); } } } if (obufcount == obuf.length) return obuf; byte[] ret = new byte[obufcount]; System.arraycopy(obuf, 0, ret, 0, obufcount); return ret; } /** * Decode a Base64 data. * * Original method name is <em>decode</em>. */ public static byte[] Decode(String data) { char[] ibuf = new char[4]; int ibufcount = 0; byte[] obuf = new byte[data.length() / 4 * 3 + 3]; int obufcount = 0; for (int i = 0; i < data.length(); i++) { char ch = data.charAt(i); if (ch == S_BASE64PAD || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) { ibuf[ibufcount++] = ch; if (ibufcount == ibuf.length) { ibufcount = 0; obufcount += Decode0(ibuf, obuf, obufcount); } } } if (obufcount == obuf.length) return obuf; byte[] ret = new byte[obufcount]; System.arraycopy(obuf, 0, ret, 0, obufcount); return ret; } /** * Checks input string for invalid Base64 characters * * @param data * @return true, if String contains only valid Base64 characters. false, * otherwise */ public static boolean IsValidBase64Encoding(String data) { for (int i = 0; i < data.length(); i++) { char ch = data.charAt(i); if (ch == S_BASE64PAD || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) { //valid character.Do nothing } else if (ch == '\r' || ch == '\n') { //do nothing } else { return false; } } //iterate over all characters in the string return true; } /** * Decode a Base64 data. * * Original method name is <em>decode</em>. */ public static void Decode(char[] data, int off, int len, OutputStream ostream) throws IOException { char[] ibuf = new char[4]; int ibufcount = 0; byte[] obuf = new byte[3]; for (int i = off; i < off + len; i++) { char ch = data[i]; if (ch == S_BASE64PAD || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) { ibuf[ibufcount++] = ch; if (ibufcount == ibuf.length) { ibufcount = 0; int obufcount = Decode0(ibuf, obuf, 0); ostream.write(obuf, 0, obufcount); } } } } /** * Decode a Base64 data. * * Original method name is <em>decode</em>. */ public static void Decode(String data, OutputStream ostream) throws IOException { char[] ibuf = new char[4]; int ibufcount = 0; byte[] obuf = new byte[3]; for (int i = 0; i < data.length(); i++) { char ch = data.charAt(i); if (ch == S_BASE64PAD || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) { ibuf[ibufcount++] = ch; if (ibufcount == ibuf.length) { ibufcount = 0; int obufcount = Decode0(ibuf, obuf, 0); ostream.write(obuf, 0, obufcount); } } } } /** * Returns base64 representation of specified byte array. * * Original method name is <em>encode</em>. */ public static String Encode(byte[] data) { return Encode(data, 0, data.length); } /** * Returns base64 representation of specified byte array. * * Original method name is <em>encode</em>. */ public static String Encode(byte[] data, int off, int len) { if (len <= 0) return ""; char[] out = new char[len / 3 * 4 + 4]; int rindex = off; int windex = 0; int rest = len - off; while (rest >= 3) { int i = ((data[rindex] & 0xff) << 16) + ((data[rindex + 1] & 0xff) << 8) + (data[rindex + 2] & 0xff); out[windex++] = S_BASE64CHAR[i >> 18]; out[windex++] = S_BASE64CHAR[(i >> 12) & 0x3f]; out[windex++] = S_BASE64CHAR[(i >> 6) & 0x3f]; out[windex++] = S_BASE64CHAR[i & 0x3f]; rindex += 3; rest -= 3; } if (rest == 1) { int i = data[rindex] & 0xff; out[windex++] = S_BASE64CHAR[i >> 2]; out[windex++] = S_BASE64CHAR[(i << 4) & 0x3f]; out[windex++] = S_BASE64PAD; out[windex++] = S_BASE64PAD; } else if (rest == 2) { int i = ((data[rindex] & 0xff) << 8) + (data[rindex + 1] & 0xff); out[windex++] = S_BASE64CHAR[i >> 10]; out[windex++] = S_BASE64CHAR[(i >> 4) & 0x3f]; out[windex++] = S_BASE64CHAR[(i << 2) & 0x3f]; out[windex++] = S_BASE64PAD; } return new String(out, 0, windex); } /** * Outputs base64 representation of the specified byte array to the * specified String Buffer */ public static void Encode(byte[] data, int off, int len, StringBuffer buffer) { if (len <= 0) { return; } char[] out = new char[4]; int rindex = off; int rest = len - off; while (rest >= 3) { int i = ((data[rindex] & 0xff) << 16) + ((data[rindex + 1] & 0xff) << 8) + (data[rindex + 2] & 0xff); out[0] = S_BASE64CHAR[i >> 18]; out[1] = S_BASE64CHAR[(i >> 12) & 0x3f]; out[2] = S_BASE64CHAR[(i >> 6) & 0x3f]; out[3] = S_BASE64CHAR[i & 0x3f]; buffer.append(out); rindex += 3; rest -= 3; } if (rest == 1) { int i = data[rindex] & 0xff; out[0] = S_BASE64CHAR[i >> 2]; out[1] = S_BASE64CHAR[(i << 4) & 0x3f]; out[2] = S_BASE64PAD; out[3] = S_BASE64PAD; buffer.append(out); } else if (rest == 2) { int i = ((data[rindex] & 0xff) << 8) + (data[rindex + 1] & 0xff); out[0] = S_BASE64CHAR[i >> 10]; out[1] = S_BASE64CHAR[(i >> 4) & 0x3f]; out[2] = S_BASE64CHAR[(i << 2) & 0x3f]; out[3] = S_BASE64PAD; buffer.append(out); } } /** * Outputs base64 representation of the specified byte array to a byte * stream. * * Original method name is <em>encode</em>. */ public static void Encode(byte[] data, int off, int len, OutputStream ostream) throws IOException { if (len <= 0) return; byte[] out = new byte[4]; int rindex = off; int rest = len - off; while (rest >= 3) { int i = ((data[rindex] & 0xff) << 16) + ((data[rindex + 1] & 0xff) << 8) + (data[rindex + 2] & 0xff); out[0] = (byte) S_BASE64CHAR[i >> 18]; out[1] = (byte) S_BASE64CHAR[(i >> 12) & 0x3f]; out[2] = (byte) S_BASE64CHAR[(i >> 6) & 0x3f]; out[3] = (byte) S_BASE64CHAR[i & 0x3f]; ostream.write(out, 0, 4); rindex += 3; rest -= 3; } if (rest == 1) { int i = data[rindex] & 0xff; out[0] = (byte) S_BASE64CHAR[i >> 2]; out[1] = (byte) S_BASE64CHAR[(i << 4) & 0x3f]; out[2] = (byte) S_BASE64PAD; out[3] = (byte) S_BASE64PAD; ostream.write(out, 0, 4); } else if (rest == 2) { int i = ((data[rindex] & 0xff) << 8) + (data[rindex + 1] & 0xff); out[0] = (byte) S_BASE64CHAR[i >> 10]; out[1] = (byte) S_BASE64CHAR[(i >> 4) & 0x3f]; out[2] = (byte) S_BASE64CHAR[(i << 2) & 0x3f]; out[3] = (byte) S_BASE64PAD; ostream.write(out, 0, 4); } } /** * Outputs base64 representation of the specified byte array to a character * stream. * * Original method name is <em>encode</em>. */ public static void Encode(byte[] data, int off, int len, Writer writer) throws IOException { if (len <= 0) return; char[] out = new char[4]; int rindex = off; int rest = len - off; int output = 0; while (rest >= 3) { int i = ((data[rindex] & 0xff) << 16) + ((data[rindex + 1] & 0xff) << 8) + (data[rindex + 2] & 0xff); out[0] = S_BASE64CHAR[i >> 18]; out[1] = S_BASE64CHAR[(i >> 12) & 0x3f]; out[2] = S_BASE64CHAR[(i >> 6) & 0x3f]; out[3] = S_BASE64CHAR[i & 0x3f]; writer.write(out, 0, 4); rindex += 3; rest -= 3; output += 4; if (output % 76 == 0) writer.write("\n"); } if (rest == 1) { int i = data[rindex] & 0xff; out[0] = S_BASE64CHAR[i >> 2]; out[1] = S_BASE64CHAR[(i << 4) & 0x3f]; out[2] = S_BASE64PAD; out[3] = S_BASE64PAD; writer.write(out, 0, 4); } else if (rest == 2) { int i = ((data[rindex] & 0xff) << 8) + (data[rindex + 1] & 0xff); out[0] = S_BASE64CHAR[i >> 10]; out[1] = S_BASE64CHAR[(i >> 4) & 0x3f]; out[2] = S_BASE64CHAR[(i << 2) & 0x3f]; out[3] = S_BASE64PAD; writer.write(out, 0, 4); } } }