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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  package org.apache.commons.lang3.text;
18  
19  import java.text.FieldPosition;
20  import java.text.Format;
21  import java.text.ParseException;
22  import java.text.ParsePosition;
23  
24  /**
25   * Formats using one formatter and parses using a different formatter. An
26   * example of use for this would be a webapp where data is taken in one way and
27   * stored in a database another way.
28   */
29  public class CompositeFormat extends Format {
30  
31      /**
32       * Required for serialization support.
33       * 
34       * @see java.io.Serializable
35       */
36      private static final long serialVersionUID = -4329119827877627683L;
37  
38      /** The parser to use. */
39      private final Format parser;
40      /** The formatter to use. */
41      private final Format formatter;
42  
43      /**
44       * Create a format that points its parseObject method to one implementation
45       * and its format method to another.
46       * 
47       * @param parser implementation
48       * @param formatter implementation
49       */
50      public CompositeFormat(final Format parser, final Format formatter) {
51          this.parser = parser;
52          this.formatter = formatter;
53      }
54  
55      /**
56       * Uses the formatter Format instance.
57       * 
58       * @param obj the object to format
59       * @param toAppendTo the {@link StringBuffer} to append to
60       * @param pos the FieldPosition to use (or ignore).
61       * @return <code>toAppendTo</code>
62       * @see Format#format(Object, StringBuffer, FieldPosition)
63       */
64      @Override // Therefore has to use StringBuffer
65      public StringBuffer format(final Object obj, final StringBuffer toAppendTo,
66              final FieldPosition pos) {
67          return formatter.format(obj, toAppendTo, pos);
68      }
69  
70      /**
71       * Uses the parser Format instance.
72       * 
73       * @param source the String source
74       * @param pos the ParsePosition containing the position to parse from, will
75       *            be updated according to parsing success (index) or failure
76       *            (error index)
77       * @return the parsed Object
78       * @see Format#parseObject(String, ParsePosition)
79       */
80      @Override
81      public Object parseObject(final String source, final ParsePosition pos) {
82          return parser.parseObject(source, pos);
83      }
84  
85      /**
86       * Provides access to the parser Format implementation.
87       * 
88       * @return parser Format implementation
89       */
90      public Format getParser() {
91          return this.parser;
92      }
93  
94      /**
95       * Provides access to the parser Format implementation.
96       * 
97       * @return formatter Format implementation
98       */
99      public Format getFormatter() {
100         return this.formatter;
101     }
102 
103     /**
104      * Utility method to parse and then reformat a String.
105      * 
106      * @param input String to reformat
107      * @return A reformatted String
108      * @throws ParseException thrown by parseObject(String) call
109      */
110     public String reformat(final String input) throws ParseException {
111         return format(parseObject(input));
112     }
113 
114 }