Java Integer From intFromBase64(String value)

Description

int From Base

License

Apache License

Declaration

public static int intFromBase64(String value) 

Method Source Code

//package com.java2s;
/*// w w  w  . ja  v a  2s . c  om
 * Copyright 2009 Google Inc.
 * 
 * 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.
 */

public class Main {
    /**
     * An array mapping legal base 64 characters [a-zA-Z0-9$_] to their associated
     * 6-bit values. The source indices will be given by 7-bit ASCII characters,
     * thus the array size needs to be 128 (actually 123 would suffice for the
     * given set of characters in use).
     */
    private static final byte[] base64Values = new byte[128];

    public static int intFromBase64(String value) {
        return (int) longFromBase64(value);
    }

    /**
     * Decode a base64 string into a long value.
     */
    public static long longFromBase64(String value) {
        int pos = 0;
        long longVal = base64Values[value.charAt(pos++)];
        int len = value.length();
        while (pos < len) {
            longVal <<= 6;
            longVal |= base64Values[value.charAt(pos++)];
        }
        return longVal;
    }
}

Related

1. intFrom(byte a, byte b, byte c, byte d)
2. intFrom2Bytes(byte[] bytes, int index)
3. intFrom4Bytes(byte[] bytes, int index)
4. intFromBigEndainByteArray(byte[] buf, int offset, int len)
5. intFromByte(byte byteValue)
6. intFromByteArray(final byte[] buf, final int offset)
7. intFromByteArray(final byte[] byteArray)