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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
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.commons.net.ftp.parser;
19  
20  import java.text.ParseException;
21  import java.util.Calendar;
22  
23  import org.apache.commons.net.ftp.Configurable;
24  import org.apache.commons.net.ftp.FTPClientConfig;
25  
26  /**
27   * <p>
28   * This abstract class implements the common timestamp parsing algorithm for all the concrete parsers. Classes derived from this one will parse file listings
29   * via a supplied regular expression that pulls out the date portion as a separate string which is passed to the underlying {@link FTPTimestampParser delegate}
30   * to handle parsing of the file timestamp.
31   * <p>
32   * This class also implements the {@link Configurable Configurable} interface to allow the parser to be configured from the outside.
33   *
34   * @since 1.4
35   */
36  public abstract class ConfigurableFTPFileEntryParserImpl extends RegexFTPFileEntryParserImpl implements Configurable {
37  
38      private final FTPTimestampParser timestampParser;
39  
40      /**
41       * constructor for this abstract class.
42       *
43       * @param regex Regular expression used main parsing of the file listing.
44       */
45      public ConfigurableFTPFileEntryParserImpl(final String regex) {
46          super(regex);
47          this.timestampParser = new FTPTimestampParserImpl();
48      }
49  
50      /**
51       * constructor for this abstract class.
52       *
53       * @param regex Regular expression used main parsing of the file listing.
54       * @param flags the flags to apply, see {@link java.util.regex.Pattern#compile(String, int) Pattern#compile(String, int)}. Use 0 for none.
55       * @since 3.4
56       */
57      public ConfigurableFTPFileEntryParserImpl(final String regex, final int flags) {
58          super(regex, flags);
59          this.timestampParser = new FTPTimestampParserImpl();
60      }
61  
62      /**
63       * Implementation of the {@link Configurable Configurable} interface. Configures this parser by delegating to the underlying Configurable FTPTimestampParser
64       * implementation, ' passing it the supplied {@link FTPClientConfig FTPClientConfig} if that is non-null or a default configuration defined by each concrete
65       * subclass.
66       *
67       * @param config the configuration to be used to configure this parser. If it is null, a default configuration defined by each concrete subclass is used
68       *               instead.
69       */
70      @Override
71      public void configure(final FTPClientConfig config) {
72          if (this.timestampParser instanceof Configurable) {
73              final FTPClientConfig defaultCfg = getDefaultConfiguration();
74              if (config != null) {
75                  if (null == config.getDefaultDateFormatStr()) {
76                      config.setDefaultDateFormatStr(defaultCfg.getDefaultDateFormatStr());
77                  }
78                  if (null == config.getRecentDateFormatStr()) {
79                      config.setRecentDateFormatStr(defaultCfg.getRecentDateFormatStr());
80                  }
81                  ((Configurable) this.timestampParser).configure(config);
82              } else {
83                  ((Configurable) this.timestampParser).configure(defaultCfg);
84              }
85          }
86      }
87  
88      /**
89       * Each concrete subclass must define this member to create a default configuration to be used when that subclass is instantiated without a
90       * {@link FTPClientConfig FTPClientConfig} parameter being specified.
91       *
92       * @return the default configuration for the subclass.
93       */
94      protected abstract FTPClientConfig getDefaultConfiguration();
95  
96      /**
97       * This method is called by the concrete parsers to delegate timestamp parsing to the timestamp parser.
98       *
99       * @param timestampStr the timestamp string pulled from the file listing by the regular expression parser, to be submitted to the
100      *                     <code>timestampParser</code> for extracting the timestamp.
101      * @return a <code>java.util.Calendar</code> containing results of the timestamp parse.
102      * @throws ParseException on parse error
103      */
104     public Calendar parseTimestamp(final String timestampStr) throws ParseException {
105         return this.timestampParser.parseTimestamp(timestampStr);
106     }
107 }