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1   package org.apache.maven.internal;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.ArrayList;
23  import java.util.List;
24  
25  /**
26   * Helper class to format multiline messages to the console
27   */
28  public class MultilineMessageHelper
29  {
30  
31      private static final int DEFAULT_MAX_SIZE = 65;
32      private static final char BOX_CHAR = '*';
33  
34      public static String separatorLine()
35      {
36          StringBuilder sb = new StringBuilder( DEFAULT_MAX_SIZE );
37          repeat( sb, '*', DEFAULT_MAX_SIZE );
38          return sb.toString();
39      }
40  
41      public static List<String> format( String... lines )
42      {
43          int size = DEFAULT_MAX_SIZE;
44          int remainder = size - 4; // 4 chars = 2 box_char + 2 spaces
45          List<String> result = new ArrayList<>();
46          StringBuilder sb = new StringBuilder( size );
47          // first line
48          sb.setLength( 0 );
49          repeat( sb, BOX_CHAR, size );
50          result.add( sb.toString() );
51          // lines
52          for ( String line : lines )
53          {
54              sb.setLength( 0 );
55              String[] words = line.split( "\\s+" );
56              for ( String word : words )
57              {
58                  if ( sb.length() >= remainder - word.length() - ( sb.length() > 0 ? 1 : 0 ) )
59                  {
60                      repeat( sb, ' ', remainder - sb.length() );
61                      result.add( BOX_CHAR + " " + sb + " " + BOX_CHAR );
62                      sb.setLength( 0 );
63                  }
64                  if ( sb.length() > 0 )
65                  {
66                      sb.append( ' ' );
67                  }
68                  sb.append( word );
69              }
70  
71              while ( sb.length() < remainder )
72              {
73                  sb.append( ' ' );
74              }
75              result.add( BOX_CHAR + " " + sb + " " + BOX_CHAR );
76          }
77          // last line
78          sb.setLength( 0 );
79          repeat( sb, BOX_CHAR, size );
80          result.add( sb.toString() );
81          return result;
82      }
83  
84      private static void repeat( StringBuilder sb, char c, int nb )
85      {
86          for ( int i = 0; i < nb; i++ )
87          {
88              sb.append( c );
89          }
90      }
91  }