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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.lang3.builder;
19  
20  import org.apache.commons.lang3.ClassUtils;
21  import org.apache.commons.lang3.StringUtils;
22  
23  /**
24   * Works with {@link ToStringBuilder} to create a "deep" {@code toString}.
25   * But instead a single line like the {@link RecursiveToStringStyle} this creates a multiline String
26   * similar to the {@link ToStringStyle#MULTI_LINE_STYLE}.
27   *
28   * <p>To use this class write code as follows:</p>
29   *
30   * <pre>
31   * public class Job {
32   *   String title;
33   *   ...
34   * }
35   *
36   * public class Person {
37   *   String name;
38   *   int age;
39   *   boolean smoker;
40   *   Job job;
41   *
42   *   ...
43   *
44   *   public String toString() {
45   *     return new ReflectionToStringBuilder(this, new MultilineRecursiveToStringStyle()).toString();
46   *   }
47   * }
48   * </pre>
49   *
50   * <p>
51   * This will produce a toString of the format:<br>
52   * {@code Person@7f54[ <br>
53   * &nbsp; name=Stephen, <br>
54   * &nbsp; age=29, <br>
55   * &nbsp; smokealse, <br>
56   * &nbsp; job=Job@43cd2[ <br>
57   * &nbsp; &nbsp; title=Manager <br>
58   * &nbsp;  ] <br>
59   * ]
60   * }
61   * </p>
62   *
63   * @since 3.4
64   */
65  public class MultilineRecursiveToStringStyle extends RecursiveToStringStyle {
66  
67      /**
68       * Required for serialization support.
69       * @see java.io.Serializable
70       */
71      private static final long serialVersionUID = 1L;
72  
73      /** Indenting of inner lines. */
74      private static final int INDENT = 2;
75  
76      /** Current indenting. */
77      private int spaces = 2;
78  
79      /**
80       * Constructs a new instance.
81       */
82      public MultilineRecursiveToStringStyle() {
83          resetIndent();
84      }
85  
86      @Override
87      protected void appendDetail(final StringBuffer buffer, final String fieldName, final boolean[] array) {
88          spaces += INDENT;
89          resetIndent();
90          super.appendDetail(buffer, fieldName, array);
91          spaces -= INDENT;
92          resetIndent();
93      }
94  
95      @Override
96      protected void appendDetail(final StringBuffer buffer, final String fieldName, final byte[] array) {
97          spaces += INDENT;
98          resetIndent();
99          super.appendDetail(buffer, fieldName, array);
100         spaces -= INDENT;
101         resetIndent();
102     }
103 
104     @Override
105     protected void appendDetail(final StringBuffer buffer, final String fieldName, final char[] array) {
106         spaces += INDENT;
107         resetIndent();
108         super.appendDetail(buffer, fieldName, array);
109         spaces -= INDENT;
110         resetIndent();
111     }
112 
113     @Override
114     protected void appendDetail(final StringBuffer buffer, final String fieldName, final double[] array) {
115         spaces += INDENT;
116         resetIndent();
117         super.appendDetail(buffer, fieldName, array);
118         spaces -= INDENT;
119         resetIndent();
120     }
121 
122     @Override
123     protected void appendDetail(final StringBuffer buffer, final String fieldName, final float[] array) {
124         spaces += INDENT;
125         resetIndent();
126         super.appendDetail(buffer, fieldName, array);
127         spaces -= INDENT;
128         resetIndent();
129     }
130 
131     @Override
132     protected void appendDetail(final StringBuffer buffer, final String fieldName, final int[] array) {
133         spaces += INDENT;
134         resetIndent();
135         super.appendDetail(buffer, fieldName, array);
136         spaces -= INDENT;
137         resetIndent();
138     }
139 
140     @Override
141     protected void appendDetail(final StringBuffer buffer, final String fieldName, final long[] array) {
142         spaces += INDENT;
143         resetIndent();
144         super.appendDetail(buffer, fieldName, array);
145         spaces -= INDENT;
146         resetIndent();
147     }
148 
149     @Override
150     public void appendDetail(final StringBuffer buffer, final String fieldName, final Object value) {
151         if (!ClassUtils.isPrimitiveWrapper(value.getClass()) && !String.class.equals(value.getClass())
152                 && accept(value.getClass())) {
153             spaces += INDENT;
154             resetIndent();
155             buffer.append(ReflectionToStringBuilder.toString(value, this));
156             spaces -= INDENT;
157             resetIndent();
158         } else {
159             super.appendDetail(buffer, fieldName, value);
160         }
161     }
162 
163     @Override
164     protected void appendDetail(final StringBuffer buffer, final String fieldName, final Object[] array) {
165         spaces += INDENT;
166         resetIndent();
167         super.appendDetail(buffer, fieldName, array);
168         spaces -= INDENT;
169         resetIndent();
170     }
171 
172     @Override
173     protected void appendDetail(final StringBuffer buffer, final String fieldName, final short[] array) {
174         spaces += INDENT;
175         resetIndent();
176         super.appendDetail(buffer, fieldName, array);
177         spaces -= INDENT;
178         resetIndent();
179     }
180 
181     @Override
182     protected void reflectionAppendArrayDetail(final StringBuffer buffer, final String fieldName, final Object array) {
183         spaces += INDENT;
184         resetIndent();
185         super.reflectionAppendArrayDetail(buffer, fieldName, array);
186         spaces -= INDENT;
187         resetIndent();
188     }
189 
190     /**
191      * Resets the fields responsible for the line breaks and indenting.
192      * Must be invoked after changing the {@link #spaces} value.
193      */
194     private void resetIndent() {
195         setArrayStart("{" + System.lineSeparator() + spacer(spaces));
196         setArraySeparator("," + System.lineSeparator() + spacer(spaces));
197         setArrayEnd(System.lineSeparator() + spacer(spaces - INDENT) + "}");
198 
199         setContentStart("[" + System.lineSeparator() + spacer(spaces));
200         setFieldSeparator("," + System.lineSeparator() + spacer(spaces));
201         setContentEnd(System.lineSeparator() + spacer(spaces - INDENT) + "]");
202     }
203 
204     /**
205      * Creates a StringBuilder responsible for the indenting.
206      *
207      * @param spaces how far to indent
208      * @return a StringBuilder with {spaces} leading space characters.
209      */
210     private String spacer(final int spaces) {
211         return StringUtils.repeat(' ', spaces);
212     }
213 
214 }