Android Byte Array Decode decode(byte[] input, int offset, int len, int flags)

Description

Decode the Base64-encoded data in input and return the data in a new byte array.

License

Apache License

Parameter

Parameter	Description
input	the data to decode
offset	the position within the input array at which to start
len	the number of bytes of input to decode
flags	controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.

Exception

Parameter	Description
IllegalArgumentException	if the input containsincorrect padding

Declaration

public static byte[] decode(byte[] input, int offset, int len, int flags) 

Method Source Code

/*/* www  .ja va2 s .c o  m*/
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed 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.
 */

import java.io.UnsupportedEncodingException;

public class Main{
    /**
     * Decode the Base64-encoded data in input and return the data in
     * a new byte array.
     *
     * <p>The padding '=' characters at the end are considered optional, but
     * if any are present, there must be the correct number of them.
     *
     * @param str    the input String to decode, which is converted to
     *               bytes using the default charset
     * @param flags  controls certain features of the decoded output.
     *               Pass {@code DEFAULT} to decode standard Base64.
     *
     * @throws IllegalArgumentException if the input contains
     * incorrect padding
     */
    public static byte[] decode(String str, int flags) {
        return decode(str.getBytes(), flags);
    }
    /**
     * Decode the Base64-encoded data in input and return the data in
     * a new byte array.
     *
     * <p>The padding '=' characters at the end are considered optional, but
     * if any are present, there must be the correct number of them.
     *
     * @param input the input array to decode
     * @param flags  controls certain features of the decoded output.
     *               Pass {@code DEFAULT} to decode standard Base64.
     *
     * @throws IllegalArgumentException if the input contains
     * incorrect padding
     */
    public static byte[] decode(byte[] input, int flags) {
        return decode(input, 0, input.length, flags);
    }
    /**
     * Decode the Base64-encoded data in input and return the data in
     * a new byte array.
     *
     * <p>The padding '=' characters at the end are considered optional, but
     * if any are present, there must be the correct number of them.
     *
     * @param input  the data to decode
     * @param offset the position within the input array at which to start
     * @param len    the number of bytes of input to decode
     * @param flags  controls certain features of the decoded output.
     *               Pass {@code DEFAULT} to decode standard Base64.
     *
     * @throws IllegalArgumentException if the input contains
     * incorrect padding
     */
    public static byte[] decode(byte[] input, int offset, int len, int flags) {
        // Allocate space for the most data the input could represent.
        // (It could contain less if it contains whitespace, etc.)
        Decoder decoder = new Decoder(flags, new byte[len * 3 / 4]);

        if (!decoder.process(input, offset, len, true)) {
            throw new IllegalArgumentException("bad base-64");
        }

        // Maybe we got lucky and allocated exactly enough output space.
        if (decoder.op == decoder.output.length) {
            return decoder.output;
        }

        // Need to shorten the array, so allocate a new one of the
        // right size and copy.
        byte[] temp = new byte[decoder.op];
        System.arraycopy(decoder.output, 0, temp, 0, decoder.op);
        return temp;
    }
}

Related

1. decode(String s)
2. decode(String s)
3. decode(byte[] input, int flags)
4. decode(byte[] source)
5. decode(byte[] source)
6. decode(byte[] source)
7. decode(byte[] source, int off, int len)