StringTokenizer


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3    *  contributor license agreements.  See the NOTICE file distributed with
4    *  this work for additional information regarding copyright ownership.
5    *  The ASF licenses this file to You under the Apache License, Version 2.0
6    *  (the "License"); you may not use this file except in compliance with
7    *  the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   *
17   */
18  package org.apache.tools.ant.util;
19  
20  import java.io.IOException  ;
21  import java.io.Reader  ;
22  import org.apache.tools.ant.ProjectComponent;
23  
24  /**
25   * Class to tokenize the input as areas separated
26   * by white space, or by a specified list of
27   * delim characters. Behaves like java.util.StringTokenizer.
28   * If the stream starts with delim characters, the first
29   * token will be an empty string (unless the treat delims
30   * as tokens flag is set).
31   * @since Ant 1.7
32   */
33  public class StringTokenizer extends ProjectComponent implements Tokenizer {
34      private String   intraString = "";
35      private int    pushed = -2;
36      private char[] delims = null;
37      private boolean delimsAreTokens = false;
38      private boolean suppressDelims = false;
39      private boolean includeDelims = false;
40  
41      /**
42       * attribute delims - the delimiter characters
43       * @param delims a string containing the delimiter characters
44       */
45      public void setDelims(String   delims) {
46          this.delims = StringUtils.resolveBackSlash(delims).toCharArray();
47      }
48  
49      /**
50       * attribute delimsaretokens - treat delimiters as
51       * separate tokens.
52       * @param delimsAreTokens true if delimiters are to be separate
53       */
54  
55      public void setDelimsAreTokens(boolean delimsAreTokens) {
56          this.delimsAreTokens = delimsAreTokens;
57      }
58      /**
59       * attribute suppressdelims - suppress delimiters.
60       * default - false
61       * @param suppressDelims if true do not report delimiters
62       */
63      public void setSuppressDelims(boolean suppressDelims) {
64          this.suppressDelims = suppressDelims;
65      }
66  
67      /**
68       * attribute includedelims - treat delimiters as part
69       * of the token.
70       * default - false
71       * @param includeDelims if true add delimiters to the token
72       */
73      public void setIncludeDelims(boolean includeDelims) {
74          this.includeDelims = includeDelims;
75      }
76  
77      /**
78       * find and return the next token
79       *
80       * @param in the input stream
81       * @return the token
82       * @exception IOException if an error occurs reading
83       */
84      public String   getToken(Reader   in) throws IOException   {
85          int ch = -1;
86          if (pushed != -2) {
87              ch = pushed;
88              pushed = -2;
89          } else {
90              ch = in.read();
91          }
92          if (ch == -1) {
93              return null;
94          }
95          boolean inToken = true;
96          intraString = "";
97          StringBuffer   word = new StringBuffer  ();
98          StringBuffer   padding = new StringBuffer  ();
99          while (ch != -1) {
100             char c = (char) ch;
101             boolean isDelim = isDelim(c);
102             if (inToken) {
103                 if (isDelim) {
104                     if (delimsAreTokens) {
105                         if (word.length() == 0) {
106                             word.append(c);
107                         } else {
108                             pushed = ch;
109                         }
110                         break;
111                     }
112                     padding.append(c);
113                     inToken = false;
114                 } else {
115                     word.append(c);
116                 }
117             } else {
118                 if (isDelim) {
119                     padding.append(c);
120                 } else {
121                     pushed = ch;
122                     break;
123                 }
124             }
125             ch = in.read();
126         }
127         intraString = padding.toString();
128         if (includeDelims) {
129             word.append(intraString);
130         }
131         return word.toString();
132     }
133 
134     /**
135      * @return the intratoken string
136      */
137     public String   getPostToken() {
138         return suppressDelims || includeDelims ? "" : intraString;
139     }
140 
141     private boolean isDelim(char ch) {
142         if (delims == null) {
143             return Character.isWhitespace(ch);
144         }
145         for (int i = 0; i < delims.length; ++i) {
146             if (delims[i] == ch) {
147                 return true;
148             }
149         }
150         return false;
151     }
152 }
153
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