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      1 /*
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      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  *   - Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  *
     11  *   - Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  *
     15  *   - Neither the name of Oracle nor the names of its
     16  *     contributors may be used to endorse or promote products derived
     17  *     from this software without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
     20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 import java.io.IOException;
     33 import java.lang.reflect.Field;
     34 
     35 /**
     36  * The example illustrates how to use the default method for mixin.
     37  * @see BuildType
     38  * @see Debuggable
     39  */
     40 public class MixIn {
     41 
     42     /**
     43      * Implement this interface for a class that must be in debug print
     44      */
     45     public interface Debuggable {
     46 
     47         /**
     48          * Print the class name and all fields to a string. Uses reflection to
     49          * obtain and access fields of this object.
     50          *
     51          * @return the string formatted like the following: <pre>
     52          * State of the: &lt;Class Name&gt;
     53          * &lt;member name&gt; : &lt;value&gt;
     54          * ...
     55          * </pre>
     56          */
     57         default String toDebugString() {
     58             StringBuilder sb = new StringBuilder();
     59             sb.append("State of the: ").append(
     60                     this.getClass().getSimpleName()).append("\n");
     61             for (Class cls = this.getClass();
     62                     cls != null;
     63                     cls = cls.getSuperclass()) {
     64                 for (Field f : cls.getDeclaredFields()) {
     65                     try {
     66                         f.setAccessible(true);
     67                         sb.append(f.getName()).append(" : ").
     68                                 append(f.get(this)).append("\n");
     69                     } catch (IllegalAccessException e) {
     70                     }
     71                 }
     72             }
     73             return sb.toString();
     74         }
     75     }
     76 
     77     /**
     78      * Sample exception class to demonstrate mixin. This enum inherits the
     79      * behavior of the {@link Debuggable}
     80      */
     81     public static enum BuildType implements Debuggable {
     82 
     83         BUILD(0, "-build"),
     84         PLAN(0, "-plan"),
     85         EXCLUDE(1, "-exclude"),
     86         TOTAL(2, "-total");
     87 
     88         private final int compareOrder;
     89         private final String pathSuffix;
     90 
     91         private BuildType(int compareOrder, String pathSuffix) {
     92             this.compareOrder = compareOrder;
     93             this.pathSuffix = pathSuffix;
     94         }
     95 
     96         public int getCompareOrder() {
     97             return compareOrder;
     98         }
     99 
    100         public String getPathSuffix() {
    101             return pathSuffix;
    102         }
    103     }
    104 
    105     /**
    106      * Illustrate the behavior of the MixClass
    107      *
    108      * @param args command-line arguments
    109      * @throws java.io.IOException internal demo error
    110      */
    111     public static void main(final String[] args) throws IOException {
    112         System.out.println(BuildType.BUILD.toDebugString());
    113     }
    114 }
    115