Here you can find the source of base64Encode(String s)
public static String base64Encode(String s)
//package com.java2s; /*/*w w w . j a va 2 s.co m*/ * Copyright (c) 2001-2007 Sun Microsystems, Inc. All rights reserved. * * The Sun Project JXTA(TM) Software License * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The end-user documentation included with the redistribution, if any, must * include the following acknowledgment: "This product includes software * developed by Sun Microsystems, Inc. for JXTA(TM) technology." * Alternately, this acknowledgment may appear in the software itself, if * and wherever such third-party acknowledgments normally appear. * * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must * not be used to endorse or promote products derived from this software * without prior written permission. For written permission, please contact * Project JXTA at http://www.jxta.org. * * 5. Products derived from this software may not be called "JXTA", nor may * "JXTA" appear in their name, without prior written permission of Sun. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN * MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * JXTA is a registered trademark of Sun Microsystems, Inc. in the United * States and other countries. * * Please see the license information page at : * <http://www.jxta.org/project/www/license.html> for instructions on use of * the license in source files. * * ==================================================================== * * This software consists of voluntary contributions made by many individuals * on behalf of Project JXTA. For more information on Project JXTA, please see * http://www.jxta.org. * * This license is based on the BSD license adopted by the Apache Foundation. */ import java.io.StringReader; import java.io.IOException; public class Main { private static final boolean VERBOSE = false; private static byte[] code = new byte[64]; public static String base64Encode(String s) { StringBuilder sb = new StringBuilder(); StringReader r = new StringReader(s); int c = 0; int d = 0; int e = 0; int k = 0; int end = 0; byte u; byte v; byte w; byte x; while (end == 0) { try { if ((c = r.read()) == -1) { c = 0; end = 1; } if ((d = r.read()) == -1) { d = 0; end += 1; } if ((e = r.read()) == -1) { e = 0; end += 1; } } catch (IOException ioe) { if (VERBOSE) { ioe.printStackTrace(); } sb = null; break; } u = code[c >> 2]; v = code[(3 & c) << 4 | d >> 4]; w = code[(15 & d) << 2 | e >> 6]; x = code[e & 63]; if (k == 76) { k = 0; System.out.println(""); } if (end >= 1) { x = (byte) '='; } if (end == 2) { w = (byte) '='; } if (end < 3) { sb.append("" + (char) u + (char) v + (char) w + (char) x); } k += 4; } return sb != null ? sb.toString() : null; } }