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 }