utility to generate an int from an array of bytes in BigEndian order - Java Internationalization

Java examples for Internationalization:Big Endian Little Endian

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Description

utility to generate an int from an array of bytes in BigEndian order

Demo Code

/**//from   w  w w . j a v a 2  s . c  o  m
 * static byte array utilities
 *
 * Copyright (c) 2004, Pat Farrell, All rights reserved.
 * 
 * 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. * 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.
 */
//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        byte[] buf = new byte[] { 34, 35, 36, 37, 37, 37, 67, 68, 69 };
        int offset = 2;
        int len = 2;
        System.out.println(intFromBigEndianByteArray(buf, offset, len));
    }

    /** utility to generate an int from an array of bytes in BigEndian order
     * @param buf byte array source
     * @param offset into the array
     * @param len number of bytes to use, must be 4 or less
     * @return an int
     */
    public static int intFromBigEndianByteArray(byte[] buf, int offset,
            int len) {
        return (int) longFromBigEndianArray(buf, offset, len);
    }

    /** 
     * utility to build a long from values in an array of bytes in bigEndian order
     * @param buf byte array source
     * @param offset offset into array
     * @param len number to read (must be  8 or less
     * @return a long
     */
    public static long longFromBigEndianArray(byte[] buf, int offset,
            int len) {
        long val = 0;
        for (int i = 0; i < len; i++) {
            val = val << 8;
            int d = (0xff & buf[i + offset]);
            val += d;
        }
        return val;
    }
}

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