/*
* This file is part of muCommander, http://www.mucommander.com
* Copyright (C) 2002-2016 Maxence Bernard
*
* muCommander is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* muCommander is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.mucommander.commons.io.base64;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
/**
* <code>Base64Encoder</code> provides methods to ease the encoding of strings and byte arrays in base64.
* The {@link Base64OutputStream} class is used under the hood to perform the actual base64 encoding.
*
* @see Base64OutputStream
* @author Maxence Bernard
*/
public abstract class Base64Encoder {
/**
* Shorthand for {@link #encode(byte[], Base64Table)} invoked with {@link Base64Table#STANDARD_TABLE}.
*
* @param b bytes to base64-encode
* @return the base64-encoded String
*/
public static String encode(byte[] b) {
return encode(b, 0, b.length, Base64Table.STANDARD_TABLE);
}
/**
* Base64-encodes the given byte array using {@link Base64Table#STANDARD_TABLE} using the given Base64 table
* and returns the result.
*
* @param b bytes to base64-encode
* @param table the table to use to encode data
* @return the base64-encoded String
*/
public static String encode(byte[] b, Base64Table table) {
return encode(b, 0, b.length, table);
}
/**
* Shorthand for {@link #encode(byte[], int, int, Base64Table)} invoked with {@link Base64Table#STANDARD_TABLE}.
*
* @param b bytes to base64-encode
* @param off position to the first byte in the array to be encoded
* @param len number of bytes in the array to encode
* @return the base64-encoded String
*/
public static String encode(byte[] b, int off, int len) {
return encode(b, off, len, Base64Table.STANDARD_TABLE);
}
/**
* Base64-encodes the given byte array, from off to len, and returns the result.
*
* @param b bytes to base64-encode
* @param off position to the first byte in the array to be encoded
* @param len number of bytes in the array to encode
* @param table the table to use to encode data
* @return the base64-encoded String
*/
public static String encode(byte[] b, int off, int len, Base64Table table) {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
Base64OutputStream out64 = new Base64OutputStream(bout, false, table);
try {
out64.write(b, off, len);
out64.writePadding();
return new String(bout.toByteArray());
}
catch(IOException e) {
// Should never happen
return null;
}
finally {
try { out64.close(); }
catch(IOException e) {
// Should never happen
}
}
}
/**
* Shorthand for {@link #encode(String, String, Base64Table)} invoked with <code>UTF-8</code> encoding and
* {@link Base64Table#STANDARD_TABLE}.
*
* @param s the String to base64-encode
* @return the base64-encoded String
*/
public static String encode(String s) {
try {
return encode(s, "UTF-8", Base64Table.STANDARD_TABLE);
}
catch(UnsupportedEncodingException e) {
// Should never happen, UTF-8 is necessarily supported by the Java runtime
return null;
}
}
/**
* Base64-encodes the given String and returns result. The specified encoding is used for tranforming
* the string into bytes.
*
* @param s the String to base64-encode
* @param encoding the character encoding to use for transforming the string into bytes
* @param table the table to use to encode data
* @return the base64-encoded String
* @throws UnsupportedEncodingException if the specified encoding is not supported by the Java runtime
*/
public static String encode(String s, String encoding, Base64Table table) throws UnsupportedEncodingException {
return encode(s.getBytes(encoding), table);
}
}