Support combine.keys

codehaus-plexus · Dec 7, 2019 · 844da90 · 844da90
2 parents 89f74c5 + 177a0cd
commit 844da90
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Showing 3 changed files with 73 additions and 3 deletions.
diff --git a/pom.xml b/pom.xml
@@ -26,7 +26,7 @@ limitations under the License.
   </parent>
 
   <artifactId>plexus-utils</artifactId>
-  <version>3.3.1-SNAPSHOT</version>
+  <version>3.4.0-SNAPSHOT</version>
 
   <name>Plexus Common Utilities</name>
   <description>A collection of various utility classes to ease working with strings, files, command lines, XML and

diff --git a/src/main/java/org/codehaus/plexus/util/xml/Xpp3DomUtils.java b/src/main/java/org/codehaus/plexus/util/xml/Xpp3DomUtils.java
@@ -19,9 +19,7 @@
 import org.codehaus.plexus.util.xml.pull.XmlSerializer;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.Map;
 
 /** @author Jason van Zyl */
@@ -52,6 +50,14 @@ public class Xpp3DomUtils
      * @since 3.0.22
      */
     public static final String ID_COMBINATION_MODE_ATTRIBUTE = "combine.id";
+
+    /**
+     * In case of complex XML structures, combining can be done based on keys.
+     * This is a comma separated list of attribute names.
+     * 
+     * @Since 3.4.0
+     */
+    public static final String KEYS_COMBINATION_MODE_ATTRIBUTE = "combine.keys";
 
     /**
      * This default mode for combining a DOM node during merge means that where element names match, the process will
@@ -106,6 +112,8 @@ public void writeToSerializer( String namespace, XmlSerializer serializer, Xpp3D
      *     <ol type="i">
      *     <li> if 'combine.id' is set and there is a corresponding dominant child (matched by value of 'combine.id'),
      *          merge the two.</li>
+     *     <li> if 'combine.keys' is set and there is a corresponding dominant child (matched by value of key elements),
+     *          merge the two.</li>
      *     <li> if mergeChildren == true and there is a corresponding dominant child (matched by element name),
      *          merge the two.</li>
      *     <li> otherwise, add the recessive child as a new child on the dominant root node.</li>
@@ -167,6 +175,7 @@ private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boole
             for ( Xpp3Dom recessiveChild : children )
             {
                 String idValue = recessiveChild.getAttribute( ID_COMBINATION_MODE_ATTRIBUTE );
+                String keysValue = recessiveChild.getAttribute( KEYS_COMBINATION_MODE_ATTRIBUTE );
 
                 Xpp3Dom childDom = null;
                 if ( isNotEmpty( idValue ) )
@@ -181,6 +190,32 @@ private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boole
                         }
                     }
                 }
+                else if ( isNotEmpty( keysValue ) ) 
+                {
+                    String[] keys = keysValue.split( "," );
+                    Map<String, String> recessiveKeyValues = new HashMap<String, String>( keys.length );
+                    for ( String key : keys )
+                    {
+                        recessiveKeyValues.put( key, recessiveChild.getChild( key ).getValue() );
+                    }
+
+                    for ( Xpp3Dom dominantChild : dominant.getChildren() )
+                    {
+                        Map<String, String> dominantKeyValues = new HashMap<String, String>( keys.length );
+                        for ( String key : keys )
+                        {
+                            dominantKeyValues.put( key, dominantChild.getChild( key ).getValue() );
+                        }
+
+                        if ( recessiveKeyValues.equals( dominantKeyValues ) )
+                        {
+                            childDom = dominantChild;
+                            // we have a match, so don't append but merge
+                            mergeChildren = true;
+                        }
+                    }
+
+                }
                 else
                 {
                     childDom = dominant.getChild( recessiveChild.getName() );

diff --git a/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomUtilsTest.java b/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomUtilsTest.java
@@ -60,6 +60,41 @@ public void testCombineId()
         assertEquals( "right", p2.getChild( "value" ).getInputLocation() );
     }
 
+    @Test
+    public void testCombineKeys()
+        throws Exception
+    {
+        String lhs = "<props>" + "<property combine.keys='name'><name>LHS-ONLY</name><value>LHS</value></property>"
+                        + "<property combine.keys='name'><name>TOOVERWRITE</name><value>LHS</value></property>" + "</props>";
+
+        String rhs = "<props>" + "<property combine.keys='name'><name>RHS-ONLY</name><value>RHS</value></property>"
+            + "<property combine.keys='name'><name>TOOVERWRITE</name><value>RHS</value></property>" + "</props>";
+
+        Xpp3Dom leftDom = Xpp3DomBuilder.build( new StringReader( lhs ), new FixedInputLocationBuilder( "left" ) );
+        Xpp3Dom rightDom = Xpp3DomBuilder.build( new StringReader( rhs ), new FixedInputLocationBuilder( "right" ) );
+
+        Xpp3Dom mergeResult = Xpp3DomUtils.mergeXpp3Dom( leftDom, rightDom, true );
+        assertEquals( 3, mergeResult.getChildren( "property" ).length );
+
+        Xpp3Dom p0 = mergeResult.getChildren( "property" )[0];
+        assertEquals( "LHS-ONLY", p0.getChild( "name" ).getValue() );
+        assertEquals( "left", p0.getChild( "name" ).getInputLocation() );
+        assertEquals( "LHS", p0.getChild( "value" ).getValue() );
+        assertEquals( "left", p0.getChild( "value" ).getInputLocation() );
+
+        Xpp3Dom p1 = mergeResult.getChildren( "property" )[1];
+        assertEquals( "TOOVERWRITE", mergeResult.getChildren( "property" )[1].getChild( "name" ).getValue() );
+        assertEquals( "left", p1.getChild( "name" ).getInputLocation() );
+        assertEquals( "LHS", mergeResult.getChildren( "property" )[1].getChild( "value" ).getValue() );
+        assertEquals( "left", p1.getChild( "value" ).getInputLocation() );
+
+        Xpp3Dom p2 = mergeResult.getChildren( "property" )[2];
+        assertEquals( "RHS-ONLY", mergeResult.getChildren( "property" )[2].getChild( "name" ).getValue() );
+        assertEquals( "right", p2.getChild( "name" ).getInputLocation() );
+        assertEquals( "RHS", mergeResult.getChildren( "property" )[2].getChild( "value" ).getValue() );
+        assertEquals( "right", p2.getChild( "value" ).getInputLocation() );
+    }
+
     private static class FixedInputLocationBuilder
         implements Xpp3DomBuilder.InputLocationBuilder
     {