Java tutorial
//////////////////////////////////////////////////////////////////////////////// // checkstyle: Checks Java source code for adherence to a set of rules. // Copyright (C) 2001-2015 the original author or authors. // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This library 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 // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA //////////////////////////////////////////////////////////////////////////////// package com.puppycrawl.tools.checkstyle.utils; import java.lang.reflect.Field; import java.util.ResourceBundle; import org.apache.commons.lang3.ArrayUtils; import com.google.common.collect.ImmutableCollection; import com.google.common.collect.ImmutableMap; import com.puppycrawl.tools.checkstyle.api.TokenTypes; /** * Contains utility methods for tokens. * * @author <a href="mailto:nesterenko-aleksey@list.ru">Aleksey Nesterenko</a> */ public final class TokenUtils { /** Maps from a token name to value. */ private static final ImmutableMap<String, Integer> TOKEN_NAME_TO_VALUE; /** Maps from a token value to name. */ private static final String[] TOKEN_VALUE_TO_NAME; /** Array of all token IDs. */ private static final int[] TOKEN_IDS; /** Prefix for exception when getting token by given id. */ private static final String TOKEN_ID_EXCEPTION_PREFIX = "given id "; /** Prefix for exception when getting token by given name. */ private static final String TOKEN_NAME_EXCEPTION_PREFIX = "given name "; // initialise the constants static { final ImmutableMap.Builder<String, Integer> builder = ImmutableMap.builder(); final Field[] fields = TokenTypes.class.getDeclaredFields(); String[] tempTokenValueToName = ArrayUtils.EMPTY_STRING_ARRAY; for (final Field field : fields) { // Only process the int declarations. if (field.getType() != Integer.TYPE) { continue; } final String name = field.getName(); final int tokenValue = getIntFromField(field, name); builder.put(name, tokenValue); if (tokenValue > tempTokenValueToName.length - 1) { final String[] temp = new String[tokenValue + 1]; System.arraycopy(tempTokenValueToName, 0, temp, 0, tempTokenValueToName.length); tempTokenValueToName = temp; } tempTokenValueToName[tokenValue] = name; } TOKEN_NAME_TO_VALUE = builder.build(); TOKEN_VALUE_TO_NAME = tempTokenValueToName; final ImmutableCollection<Integer> values = TOKEN_NAME_TO_VALUE.values(); final Integer[] ids = values.toArray(new Integer[values.size()]); TOKEN_IDS = ArrayUtils.toPrimitive(ids); } /** Stop instances being created. **/ private TokenUtils() { } /** * Gets the value of a static or instance field of type int or of another primitive type * convertible to type int via a widening conversion. Does not throw any checked exceptions. * @param field from which the int should be extracted * @param object to extract the int value from * @return the value of the field converted to type int * @throws IllegalStateException if this Field object is enforcing Java language access control * and the underlying field is inaccessible * @see Field#getInt(Object) */ public static int getIntFromField(Field field, Object object) { try { return field.getInt(object); } catch (final IllegalAccessException exception) { throw new IllegalStateException(exception); } } /** * Get all token IDs that are available in TokenTypes. * @return array of token IDs */ public static int[] getAllTokenIds() { final int[] safeCopy = new int[TOKEN_IDS.length]; System.arraycopy(TOKEN_IDS, 0, safeCopy, 0, TOKEN_IDS.length); return safeCopy; } /** * Returns the name of a token for a given ID. * @param id the ID of the token name to get * @return a token name */ public static String getTokenName(int id) { if (id > TOKEN_VALUE_TO_NAME.length - 1) { throw new IllegalArgumentException(TOKEN_ID_EXCEPTION_PREFIX + id); } final String name = TOKEN_VALUE_TO_NAME[id]; if (name == null) { throw new IllegalArgumentException(TOKEN_ID_EXCEPTION_PREFIX + id); } return name; } /** * Returns the ID of a token for a given name. * @param name the name of the token ID to get * @return a token ID */ public static int getTokenId(String name) { final Integer id = TOKEN_NAME_TO_VALUE.get(name); if (id == null) { throw new IllegalArgumentException(TOKEN_NAME_EXCEPTION_PREFIX + name); } return id; } /** * Returns the short description of a token for a given name. * @param name the name of the token ID to get * @return a short description */ public static String getShortDescription(String name) { if (!TOKEN_NAME_TO_VALUE.containsKey(name)) { throw new IllegalArgumentException(TOKEN_NAME_EXCEPTION_PREFIX + name); } final String tokenTypes = "com.puppycrawl.tools.checkstyle.api.tokentypes"; final ResourceBundle bundle = ResourceBundle.getBundle(tokenTypes); return bundle.getString(name); } /** * Is argument comment-related type (SINGLE_LINE_COMMENT, * BLOCK_COMMENT_BEGIN, BLOCK_COMMENT_END, COMMENT_CONTENT). * @param type * token type. * @return true if type is comment-related type. */ public static boolean isCommentType(int type) { return type == TokenTypes.SINGLE_LINE_COMMENT || type == TokenTypes.BLOCK_COMMENT_BEGIN || type == TokenTypes.BLOCK_COMMENT_END || type == TokenTypes.COMMENT_CONTENT; } /** * Is argument comment-related type name (SINGLE_LINE_COMMENT, * BLOCK_COMMENT_BEGIN, BLOCK_COMMENT_END, COMMENT_CONTENT). * @param type * token type name. * @return true if type is comment-related type name. */ public static boolean isCommentType(String type) { return isCommentType(getTokenId(type)); } }