001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.directory.shared.asn1.util; 021 022 023import java.io.UnsupportedEncodingException; 024 025 026/** 027 * Little helper class. 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public final class Asn1StringUtils 032{ 033 /** Hex chars */ 034 private static final byte[] HEX_CHAR = new byte[] 035 { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; 036 037 /** 038 * The empty byte[] 039 */ 040 public static final byte[] EMPTY_BYTES = new byte[] 041 {}; 042 043 044 /** 045 * Helper function that dump a byte in hex form 046 * 047 * @param octet The byte to dump 048 * @return A string representation of the byte 049 */ 050 public static String dumpByte( byte octet ) 051 { 052 return new String( new byte[] 053 { '0', 'x', HEX_CHAR[( octet & 0x00F0 ) >> 4], HEX_CHAR[octet & 0x000F] } ); 054 } 055 056 057 /** 058 * Helper function that dump an array of bytes in hex form 059 * 060 * @param buffer The bytes array to dump 061 * @return A string representation of the array of bytes 062 */ 063 public static String dumpBytes( byte[] buffer ) 064 { 065 if ( buffer == null ) 066 { 067 return ""; 068 } 069 070 StringBuffer sb = new StringBuffer(); 071 072 for ( byte b : buffer ) 073 { 074 sb.append( "0x" ).append( ( char ) ( HEX_CHAR[( b & 0x00F0 ) >> 4] ) ).append( 075 ( char ) ( HEX_CHAR[b & 0x000F] ) ).append( " " ); 076 } 077 078 return sb.toString(); 079 } 080 081 082 /** 083 * Return UTF-8 encoded byte[] representation of a String 084 * 085 * @param string The string to be transformed to a byte array 086 * @return The transformed byte array 087 */ 088 public static byte[] getBytesUtf8( String string ) 089 { 090 if ( string == null ) 091 { 092 return new byte[0]; 093 } 094 095 try 096 { 097 return string.getBytes( "UTF-8" ); 098 } 099 catch ( UnsupportedEncodingException uee ) 100 { 101 return new byte[] 102 {}; 103 } 104 } 105 106 107 /** 108 * Transform a string to an array of ASCII bytes, where the byte array will contain 109 * only values in [0, 127]. 110 * 111 * @param string The byte array to transform 112 * @return The resulting string 113 */ 114 public static byte[] asciiStringToByte( String string ) 115 { 116 if ( ( string == null ) || ( string.length() == 0 ) ) 117 { 118 return EMPTY_BYTES; 119 } 120 121 byte[] result = new byte[string.length()]; 122 123 for ( int i = 0; i < result.length; i++ ) 124 { 125 result[i] = ( byte ) string.charAt( i ); 126 } 127 128 return result; 129 } 130}