Java tutorial
/* * 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.ok2c.lightmtp.util; import java.net.InetAddress; import java.net.UnknownHostException; import java.text.ParseException; import java.util.ArrayList; import java.util.List; import org.apache.http.message.ParserCursor; import org.apache.http.util.Args; import org.apache.http.util.CharArrayBuffer; public final class InetAddressRangeParser { private static final char[] COMMA = new char[] { ',' }; private static boolean isOneOf(char c, char[] delimiters) { if (delimiters != null) { for (char delimiter : delimiters) { if (c == delimiter) { return true; } } } return false; } public InetAddressRange parse(final CharArrayBuffer buffer, final ParserCursor cursor, final char[] delimiters) throws ParseException, UnknownHostException { Args.notNull(buffer, "Char array buffer"); Args.notNull(cursor, "Parser cursor"); int pos = cursor.getPos(); int indexFrom = cursor.getPos(); int indexTo = cursor.getUpperBound(); while (pos < indexTo) { char ch = buffer.charAt(pos); if (ch == '/') { break; } if (isOneOf(ch, delimiters)) { break; } pos++; } InetAddress address = InetAddress.getByName(buffer.substringTrimmed(indexFrom, pos)); int mask = 0; if (pos < indexTo && buffer.charAt(pos) == '/') { pos++; indexFrom = pos; while (pos < indexTo) { char ch = buffer.charAt(pos); if (isOneOf(ch, delimiters)) { break; } pos++; } try { mask = Integer.parseInt(buffer.substringTrimmed(indexFrom, pos)); if (mask < 0) { throw new ParseException("Negative range mask", indexFrom); } } catch (NumberFormatException ex) { throw new ParseException("Invalid range mask", indexFrom); } } cursor.updatePos(pos); return new InetAddressRange(address, mask); } public InetAddressRange parse(final String s) throws ParseException, UnknownHostException { CharArrayBuffer buffer = new CharArrayBuffer(s.length()); buffer.append(s); ParserCursor cursor = new ParserCursor(0, s.length()); return parse(buffer, cursor, COMMA); } public List<InetAddressRange> parseAll(final CharArrayBuffer buffer, final ParserCursor cursor, final char[] delimiters) throws ParseException, UnknownHostException { Args.notNull(buffer, "Char array buffer"); Args.notNull(cursor, "Parser cursor"); char[] delims = delimiters != null ? delimiters : COMMA; List<InetAddressRange> ranges = new ArrayList<InetAddressRange>(); while (!cursor.atEnd()) { ranges.add(parse(buffer, cursor, delims)); int pos = cursor.getPos(); if (pos < cursor.getUpperBound() && isOneOf(buffer.charAt(pos), delims)) { cursor.updatePos(pos + 1); } } return ranges; } public List<InetAddressRange> parseAll(final String s) throws ParseException, UnknownHostException { CharArrayBuffer buffer = new CharArrayBuffer(s.length()); buffer.append(s); ParserCursor cursor = new ParserCursor(0, s.length()); return parseAll(buffer, cursor, null); } }