001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2016 the original author or authors. 004// 005// This library is free software; you can redistribute it and/or 006// modify it under the terms of the GNU Lesser General Public 007// License as published by the Free Software Foundation; either 008// version 2.1 of the License, or (at your option) any later version. 009// 010// This library is distributed in the hope that it will be useful, 011// but WITHOUT ANY WARRANTY; without even the implied warranty of 012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 013// Lesser General Public License for more details. 014// 015// You should have received a copy of the GNU Lesser General Public 016// License along with this library; if not, write to the Free Software 017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 018//////////////////////////////////////////////////////////////////////////////// 019 020package com.puppycrawl.tools.checkstyle.utils; 021 022import java.lang.reflect.Field; 023import java.util.Locale; 024import java.util.ResourceBundle; 025 026import com.google.common.collect.ImmutableMap; 027import com.google.common.primitives.Ints; 028import com.puppycrawl.tools.checkstyle.api.TokenTypes; 029 030/** 031 * Contains utility methods for tokens. 032 * 033 * @author <a href="mailto:nesterenko-aleksey@list.ru">Aleksey Nesterenko</a> 034 */ 035public final class TokenUtils { 036 037 /** Maps from a token name to value. */ 038 private static final ImmutableMap<String, Integer> TOKEN_NAME_TO_VALUE; 039 /** Maps from a token value to name. */ 040 private static final String[] TOKEN_VALUE_TO_NAME; 041 042 /** Array of all token IDs. */ 043 private static final int[] TOKEN_IDS; 044 045 /** Prefix for exception when getting token by given id. */ 046 private static final String TOKEN_ID_EXCEPTION_PREFIX = "given id "; 047 048 /** Prefix for exception when getting token by given name. */ 049 private static final String TOKEN_NAME_EXCEPTION_PREFIX = "given name "; 050 051 // initialise the constants 052 static { 053 final ImmutableMap.Builder<String, Integer> builder = 054 ImmutableMap.builder(); 055 final Field[] fields = TokenTypes.class.getDeclaredFields(); 056 String[] tempTokenValueToName = CommonUtils.EMPTY_STRING_ARRAY; 057 for (final Field field : fields) { 058 // Only process the int declarations. 059 if (field.getType() != Integer.TYPE) { 060 continue; 061 } 062 063 final String name = field.getName(); 064 final int tokenValue = getIntFromField(field, name); 065 builder.put(name, tokenValue); 066 if (tokenValue > tempTokenValueToName.length - 1) { 067 final String[] temp = new String[tokenValue + 1]; 068 System.arraycopy(tempTokenValueToName, 0, 069 temp, 0, tempTokenValueToName.length); 070 tempTokenValueToName = temp; 071 } 072 tempTokenValueToName[tokenValue] = name; 073 } 074 075 TOKEN_NAME_TO_VALUE = builder.build(); 076 TOKEN_VALUE_TO_NAME = tempTokenValueToName; 077 TOKEN_IDS = Ints.toArray(TOKEN_NAME_TO_VALUE.values()); 078 } 079 080 /** Stop instances being created. **/ 081 private TokenUtils() { 082 } 083 084 /** 085 * Gets the value of a static or instance field of type int or of another primitive type 086 * convertible to type int via a widening conversion. Does not throw any checked exceptions. 087 * @param field from which the int should be extracted 088 * @param object to extract the int value from 089 * @return the value of the field converted to type int 090 * @throws IllegalStateException if this Field object is enforcing Java language access control 091 * and the underlying field is inaccessible 092 * @see Field#getInt(Object) 093 */ 094 public static int getIntFromField(Field field, Object object) { 095 try { 096 return field.getInt(object); 097 } 098 catch (final IllegalAccessException exception) { 099 throw new IllegalStateException(exception); 100 } 101 } 102 103 /** 104 * Get all token IDs that are available in TokenTypes. 105 * @return array of token IDs 106 */ 107 public static int[] getAllTokenIds() { 108 final int[] safeCopy = new int[TOKEN_IDS.length]; 109 System.arraycopy(TOKEN_IDS, 0, safeCopy, 0, TOKEN_IDS.length); 110 return safeCopy; 111 } 112 113 /** 114 * Returns the name of a token for a given ID. 115 * @param id the ID of the token name to get 116 * @return a token name 117 */ 118 public static String getTokenName(int id) { 119 if (id > TOKEN_VALUE_TO_NAME.length - 1) { 120 throw new IllegalArgumentException(TOKEN_ID_EXCEPTION_PREFIX + id); 121 } 122 final String name = TOKEN_VALUE_TO_NAME[id]; 123 if (name == null) { 124 throw new IllegalArgumentException(TOKEN_ID_EXCEPTION_PREFIX + id); 125 } 126 return name; 127 } 128 129 /** 130 * Returns the ID of a token for a given name. 131 * @param name the name of the token ID to get 132 * @return a token ID 133 */ 134 public static int getTokenId(String name) { 135 final Integer id = TOKEN_NAME_TO_VALUE.get(name); 136 if (id == null) { 137 throw new IllegalArgumentException(TOKEN_NAME_EXCEPTION_PREFIX + name); 138 } 139 return id; 140 } 141 142 /** 143 * Returns the short description of a token for a given name. 144 * @param name the name of the token ID to get 145 * @return a short description 146 */ 147 public static String getShortDescription(String name) { 148 if (!TOKEN_NAME_TO_VALUE.containsKey(name)) { 149 throw new IllegalArgumentException(TOKEN_NAME_EXCEPTION_PREFIX + name); 150 } 151 152 final String tokenTypes = 153 "com.puppycrawl.tools.checkstyle.api.tokentypes"; 154 final ResourceBundle bundle = ResourceBundle.getBundle(tokenTypes, Locale.ROOT); 155 return bundle.getString(name); 156 } 157 158 /** 159 * Is argument comment-related type (SINGLE_LINE_COMMENT, 160 * BLOCK_COMMENT_BEGIN, BLOCK_COMMENT_END, COMMENT_CONTENT). 161 * @param type 162 * token type. 163 * @return true if type is comment-related type. 164 */ 165 public static boolean isCommentType(int type) { 166 return type == TokenTypes.SINGLE_LINE_COMMENT 167 || type == TokenTypes.BLOCK_COMMENT_BEGIN 168 || type == TokenTypes.BLOCK_COMMENT_END 169 || type == TokenTypes.COMMENT_CONTENT; 170 } 171 172 /** 173 * Is argument comment-related type name (SINGLE_LINE_COMMENT, 174 * BLOCK_COMMENT_BEGIN, BLOCK_COMMENT_END, COMMENT_CONTENT). 175 * @param type 176 * token type name. 177 * @return true if type is comment-related type name. 178 */ 179 public static boolean isCommentType(String type) { 180 return isCommentType(getTokenId(type)); 181 } 182 183}