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.ber.tlv; 021 022 023import org.apache.directory.shared.i18n.I18n; 024 025 026/** 027 * Parse and decode an Integer value. 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public final class IntegerDecoder 032{ 033 /** A mask used to get only the necessary bytes */ 034 private static final int[] MASK = new int[] 035 { 0x000000FF, 0x0000FFFF, 0x00FFFFFF, 0xFFFFFFFF }; 036 037 038 /** 039 * Parse a byte buffer and send back an integer, controlling that this number 040 * is in a specified interval. 041 * 042 * @param value The byte buffer to parse 043 * @param min Lowest value allowed, included 044 * @param max Highest value allowed, included 045 * @return An integer 046 * @throws IntegerDecoderException Thrown if the byte stream does not contains an integer 047 */ 048 public static int parse( Value value, int min, int max ) throws IntegerDecoderException 049 { 050 051 int result = 0; 052 053 byte[] bytes = value.getData(); 054 055 if ( ( bytes == null ) || ( bytes.length == 0 ) ) 056 { 057 throw new IntegerDecoderException( I18n.err( I18n.ERR_00036_0_BYTES_LONG_INTEGER ) ); 058 } 059 060 if ( bytes.length > 4 ) 061 { 062 throw new IntegerDecoderException( I18n.err( I18n.ERR_00037_ABOVE_4_BYTES_INTEGER ) ); 063 } 064 065 for ( int i = 0; ( i < bytes.length ) && ( i < 5 ); i++ ) 066 { 067 result = ( result << 8 ) | ( bytes[i] & 0x00FF ); 068 } 069 070 if ( ( bytes[0] & 0x80 ) == 0x80 ) 071 { 072 result = -( ( ( ~result ) + 1 ) & MASK[bytes.length - 1] ); 073 } 074 075 if ( ( result >= min ) && ( result <= max ) ) 076 { 077 return result; 078 } 079 else 080 { 081 throw new IntegerDecoderException( I18n.err( I18n.ERR_00038_VALUE_NOT_IN_RANGE, min, max ) ); 082 } 083 } 084 085 086 /** 087 * Parse a byte buffer and send back an integer 088 * 089 * @param value The byte buffer to parse 090 * @return An integer 091 * @throws IntegerDecoderException Thrown if the byte stream does not contains an integer 092 */ 093 public static int parse( Value value ) throws IntegerDecoderException 094 { 095 return parse( value, Integer.MIN_VALUE, Integer.MAX_VALUE ); 096 } 097}