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Android example source code file (HexDump.java)

This example Android source code file (HexDump.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

a, f, hex_digits, hexdump, invalid, runtimeexception, string, stringbuilder

The HexDump.java Android example source code

/*
 * Copyright (C) 2006 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.
 */

package com.android.internal.util;

public class HexDump
{
    private final static char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
    
    public static String dumpHexString(byte[] array)
    {
        return dumpHexString(array, 0, array.length);
    }
    
    public static String dumpHexString(byte[] array, int offset, int length)
    {
        StringBuilder result = new StringBuilder();
        
        byte[] line = new byte[16];
        int lineIndex = 0;
        
        result.append("\n0x");
        result.append(toHexString(offset));
        
        for (int i = offset ; i < offset + length ; i++)
        {
            if (lineIndex == 16)
            {
                result.append(" ");
                
                for (int j = 0 ; j < 16 ; j++)
                {
                    if (line[j] > ' ' && line[j] < '~')
                    {
                        result.append(new String(line, j, 1));
                    }
                    else
                    {
                        result.append(".");
                    }
                }
                
                result.append("\n0x");
                result.append(toHexString(i));
                lineIndex = 0;
            }
            
            byte b = array[i];
            result.append(" ");
            result.append(HEX_DIGITS[(b >>> 4) & 0x0F]);
            result.append(HEX_DIGITS[b & 0x0F]);
            
            line[lineIndex++] = b;
        }
        
        if (lineIndex != 16)
        {
            int count = (16 - lineIndex) * 3;
            count++;
            for (int i = 0 ; i < count ; i++)
            {
                result.append(" ");
            }
            
            for (int i = 0 ; i < lineIndex ; i++)
            {
                if (line[i] > ' ' && line[i] < '~')
                {
                    result.append(new String(line, i, 1));
                }
                else
                {
                    result.append(".");
                }
            }
        }
        
        return result.toString();
    }
    
    public static String toHexString(byte b)
    {
        return toHexString(toByteArray(b));
    }

    public static String toHexString(byte[] array)
    {
        return toHexString(array, 0, array.length);
    }
    
    public static String toHexString(byte[] array, int offset, int length)
    {
        char[] buf = new char[length * 2];

        int bufIndex = 0;
        for (int i = offset ; i < offset + length; i++) 
        {
            byte b = array[i];
            buf[bufIndex++] = HEX_DIGITS[(b >>> 4) & 0x0F];
            buf[bufIndex++] = HEX_DIGITS[b & 0x0F];
        }

        return new String(buf);        
    }
    
    public static String toHexString(int i)
    {
        return toHexString(toByteArray(i));
    }
    
    public static byte[] toByteArray(byte b)
    {
        byte[] array = new byte[1];
        array[0] = b;
        return array;
    }
    
    public static byte[] toByteArray(int i)
    {
        byte[] array = new byte[4];
        
        array[3] = (byte)(i & 0xFF);
        array[2] = (byte)((i >> 8) & 0xFF);
        array[1] = (byte)((i >> 16) & 0xFF);
        array[0] = (byte)((i >> 24) & 0xFF);
        
        return array;
    }
    
    private static int toByte(char c)
    {
        if (c >= '0' && c <= '9') return (c - '0');
        if (c >= 'A' && c <= 'F') return (c - 'A' + 10);
        if (c >= 'a' && c <= 'f') return (c - 'a' + 10);

        throw new RuntimeException ("Invalid hex char '" + c + "'");
    }
    
    public static byte[] hexStringToByteArray(String hexString)
    {
        int length = hexString.length();
        byte[] buffer = new byte[length / 2];

        for (int i = 0 ; i < length ; i += 2)
        {
            buffer[i / 2] = (byte)((toByte(hexString.charAt(i)) << 4) | toByte(hexString.charAt(i+1)));
        }
        
        return buffer;
    }    
}

Other Android examples (source code examples)

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