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
020 package org.apache.james.mime4j.stream;
021
022 /**
023 * This class represents a context of a parsing operation:
024 * <ul>
025 * <li>the current position the parsing operation is expected to start at</li>
026 * <li>the bounds limiting the scope of the parsing operation</li>
027 * </ul>
028 * <p/>
029 * Copied from Apache HttpCore project
030 */
031 public class ParserCursor {
032
033 private final int lowerBound;
034 private final int upperBound;
035 private int pos;
036
037 public ParserCursor(int lowerBound, int upperBound) {
038 super();
039 if (lowerBound < 0) {
040 throw new IndexOutOfBoundsException("Lower bound cannot be negative");
041 }
042 if (lowerBound > upperBound) {
043 throw new IndexOutOfBoundsException("Lower bound cannot be greater then upper bound");
044 }
045 this.lowerBound = lowerBound;
046 this.upperBound = upperBound;
047 this.pos = lowerBound;
048 }
049
050 public int getLowerBound() {
051 return this.lowerBound;
052 }
053
054 public int getUpperBound() {
055 return this.upperBound;
056 }
057
058 public int getPos() {
059 return this.pos;
060 }
061
062 public void updatePos(int pos) {
063 if (pos < this.lowerBound) {
064 throw new IndexOutOfBoundsException("pos: "+pos+" < lowerBound: "+this.lowerBound);
065 }
066 if (pos > this.upperBound) {
067 throw new IndexOutOfBoundsException("pos: "+pos+" > upperBound: "+this.upperBound);
068 }
069 this.pos = pos;
070 }
071
072 public boolean atEnd() {
073 return this.pos >= this.upperBound;
074 }
075
076 public String toString() {
077 StringBuilder buffer = new StringBuilder();
078 buffer.append('[');
079 buffer.append(Integer.toString(this.lowerBound));
080 buffer.append('>');
081 buffer.append(Integer.toString(this.pos));
082 buffer.append('>');
083 buffer.append(Integer.toString(this.upperBound));
084 buffer.append(']');
085 return buffer.toString();
086 }
087
088 }