View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.plugins.shade.resource.properties.io;
20  
21  import java.io.BufferedWriter;
22  import java.io.IOException;
23  import java.io.Writer;
24  
25  /**
26   * Simple buffered writer skipping its first write(String) call.
27   */
28  public class SkipPropertiesDateLineWriter extends BufferedWriter {
29      private State currentState = State.MUST_SKIP_DATE_COMMENT;
30  
31      public SkipPropertiesDateLineWriter(Writer out) {
32          super(out);
33      }
34  
35      @Override
36      public void write(String str) throws IOException {
37          if (currentState.shouldSkip(str)) {
38              currentState = currentState.next();
39              return;
40          }
41          super.write(str);
42      }
43  
44      private enum State {
45          MUST_SKIP_DATE_COMMENT {
46              @Override
47              boolean shouldSkip(String content) {
48                  return content.length() > 1 && content.startsWith("#") && !content.startsWith("# ");
49              }
50  
51              @Override
52              State next() {
53                  return SKIPPED_DATE_COMMENT;
54              }
55          },
56          SKIPPED_DATE_COMMENT {
57              @Override
58              boolean shouldSkip(String content) {
59                  return content.trim().isEmpty();
60              }
61  
62              @Override
63              State next() {
64                  return DONE;
65              }
66          },
67          DONE {
68              @Override
69              boolean shouldSkip(String content) {
70                  return false;
71              }
72  
73              @Override
74              State next() {
75                  throw new UnsupportedOperationException("done is a terminal state");
76              }
77          };
78  
79          abstract boolean shouldSkip(String content);
80  
81          abstract State next();
82      }
83  }