| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| /* |
| * Copyright 1999-2004 The Apache Software Foundation. |
| * |
| * 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.sun.org.apache.regexp.internal; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| /** |
| * Encapsulates java.io.InputStream as CharacterIterator. |
| * |
| * @author <a href="mailto:ales.novak@netbeans.com">Ales Novak</a> |
| */ |
| public final class StreamCharacterIterator implements CharacterIterator |
| { |
| /** Underlying is */ |
| private final InputStream is; |
| |
| /** Buffer of read chars */ |
| private final StringBuffer buff; |
| |
| /** read end? */ |
| private boolean closed; |
| |
| /** @param is an InputStream, which is parsed */ |
| public StreamCharacterIterator(InputStream is) |
| { |
| this.is = is; |
| this.buff = new StringBuffer(512); |
| this.closed = false; |
| } |
| |
| /** @return a substring */ |
| public String substring(int beginIndex, int endIndex) |
| { |
| try |
| { |
| ensure(endIndex); |
| return buff.toString().substring(beginIndex, endIndex); |
| } |
| catch (IOException e) |
| { |
| throw new StringIndexOutOfBoundsException(e.getMessage()); |
| } |
| } |
| |
| /** @return a substring */ |
| public String substring(int beginIndex) |
| { |
| try |
| { |
| readAll(); |
| return buff.toString().substring(beginIndex); |
| } |
| catch (IOException e) |
| { |
| throw new StringIndexOutOfBoundsException(e.getMessage()); |
| } |
| } |
| |
| |
| /** @return a character at the specified position. */ |
| public char charAt(int pos) |
| { |
| try |
| { |
| ensure(pos); |
| return buff.charAt(pos); |
| } |
| catch (IOException e) |
| { |
| throw new StringIndexOutOfBoundsException(e.getMessage()); |
| } |
| } |
| |
| /** @return <tt>true</tt> iff if the specified index is after the end of the character stream */ |
| public boolean isEnd(int pos) |
| { |
| if (buff.length() > pos) |
| { |
| return false; |
| } |
| else |
| { |
| try |
| { |
| ensure(pos); |
| return (buff.length() <= pos); |
| } |
| catch (IOException e) |
| { |
| throw new StringIndexOutOfBoundsException(e.getMessage()); |
| } |
| } |
| } |
| |
| /** Reads n characters from the stream and appends them to the buffer */ |
| private int read(int n) throws IOException |
| { |
| if (closed) |
| { |
| return 0; |
| } |
| |
| int c; |
| int i = n; |
| while (--i >= 0) |
| { |
| c = is.read(); |
| if (c < 0) // EOF |
| { |
| closed = true; |
| break; |
| } |
| buff.append((char) c); |
| } |
| return n - i; |
| } |
| |
| /** Reads rest of the stream. */ |
| private void readAll() throws IOException |
| { |
| while(! closed) |
| { |
| read(1000); |
| } |
| } |
| |
| /** Reads chars up to the idx */ |
| private void ensure(int idx) throws IOException |
| { |
| if (closed) |
| { |
| return; |
| } |
| |
| if (idx < buff.length()) |
| { |
| return; |
| } |
| |
| read(idx + 1 - buff.length()); |
| } |
| } |