Java tutorial
/* * Overchan Android (Meta Imageboard Client) * Copyright (C) 2014-2016 miku-nyan <https://github.com/miku-nyan> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package nya.miku.wishmaster.chans.dvach; import java.io.BufferedReader; import java.io.Closeable; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.lang3.StringEscapeUtils; import nya.miku.wishmaster.api.models.SimpleBoardModel; public class DvachBoardsListReader implements Closeable { private static final List<String> SFW_BOARDS = Arrays.asList(new String[] { "au", "bo", "bg", "c", "ew", "fi", "fl", "mu", "n", "ne", "ra", "s", "sn", "t", "tr", "vg", "a" }); private final Reader _in; private StringBuilder readBuffer = new StringBuilder(); private String currentCategory; private List<SimpleBoardModel> boards; private boolean end = false; private static final int FILTER_CATEGORY = 0; private static final int FILTER_BOARD = 1; private static final char[][] FILTERS = { "<dt class=\"header\"".toCharArray(), "<dd class=\"".toCharArray() }; private static final char[] CLOSE = ">".toCharArray(); private static final char[] DT_CLOSE = "</dt>".toCharArray(); private static final char[] DD_CLOSE = "</dd>".toCharArray(); private static final Pattern BOARD_PATTERN = Pattern.compile("<a href=\"/(\\w+)/\"(?:[^>]*)>(.*?)</a>", Pattern.DOTALL); public DvachBoardsListReader(Reader reader) { _in = reader; } public DvachBoardsListReader(InputStream in) { this(new BufferedReader(new InputStreamReader(in))); } public SimpleBoardModel[] readBoardsList() throws IOException { boards = new ArrayList<SimpleBoardModel>(); int filtersCount = FILTERS.length; int[] pos = new int[filtersCount]; int[] len = new int[filtersCount]; for (int i = 0; i < filtersCount; ++i) len[i] = FILTERS[i].length; int curChar; while ((curChar = _in.read()) != -1) { for (int i = 0; i < filtersCount; ++i) { if (curChar == FILTERS[i][pos[i]]) { ++pos[i]; if (pos[i] == len[i]) { handleFilter(i); pos[i] = 0; } } else { if (pos[i] != 0) pos[i] = curChar == FILTERS[i][0] ? 1 : 0; } } if (end) break; } return boards.toArray(new SimpleBoardModel[boards.size()]); } private void handleFilter(int filter) throws IOException { switch (filter) { case FILTER_CATEGORY: skipUntilSequence(CLOSE); String cat = readUntilSequence(DT_CLOSE); if (!cat.contains("?")) currentCategory = StringEscapeUtils.unescapeHtml4(cat); else end = true; break; case FILTER_BOARD: skipUntilSequence(CLOSE); String board = readUntilSequence(DD_CLOSE); Matcher boardMatcher = BOARD_PATTERN.matcher(board); if (boardMatcher.find()) { SimpleBoardModel model = new SimpleBoardModel(); model.chan = DvachModule.CHAN_NAME; model.boardName = boardMatcher.group(1); model.boardDescription = boardMatcher.group(2); model.boardCategory = currentCategory; model.nsfw = SFW_BOARDS.indexOf(model.boardName) == -1; boards.add(model); } } } private void skipUntilSequence(char[] sequence) throws IOException { int len = sequence.length; if (len == 0) return; int pos = 0; int curChar; while ((curChar = _in.read()) != -1) { if (curChar == sequence[pos]) { ++pos; if (pos == len) break; } else { if (pos != 0) pos = curChar == sequence[0] ? 1 : 0; } } } private String readUntilSequence(char[] sequence) throws IOException { int len = sequence.length; if (len == 0) return ""; readBuffer.setLength(0); int pos = 0; int curChar; while ((curChar = _in.read()) != -1) { readBuffer.append((char) curChar); if (curChar == sequence[pos]) { ++pos; if (pos == len) break; } else { if (pos != 0) pos = curChar == sequence[0] ? 1 : 0; } } int buflen = readBuffer.length(); if (buflen >= len) { readBuffer.setLength(buflen - len); return readBuffer.toString(); } else { return ""; } } @Override public void close() throws IOException { _in.close(); } }