Code cleanup - It's better (for perfs) to use a chain of append() calls than a unique append with several Strings concatenations

maven-artifact/src/main/java/org/apache/maven/artifact/resolver/AbstractArtifactResolutionException.java

@@ -199,13 +199,14 @@ public class AbstractArtifactResolutionException
         if ( message == null || !message.contains( "from the specified remote repositories:" ) )
         {
             sb.append( LS );
-            sb.append( "  " + groupId + ":" + artifactId + ":" + type + ":" + version );
+            sb.append( "  " ).append( groupId ).append( ":" ).append( artifactId ).append( ":" ).append( type ).append(
+                ":" ).append( version );
             sb.append( LS );
             if ( remoteRepositories != null )
             {
                 sb.append( LS );
                 sb.append( "from the specified remote repositories:" );
-                sb.append( LS + "  " );
+                sb.append( LS ).append( "  " );
 
                 if ( remoteRepositories.isEmpty() )
                 {

maven-compat/src/main/java/org/apache/maven/project/validation/ModelValidationResult.java

@@ -85,7 +85,8 @@ public class ModelValidationResult
 //
         for ( int i = 0; i < messages.size(); i++ )
         {
-            message.append( indentation + "[" + i + "]  " + messages.get( i ) + NEWLINE );
+            message.append( indentation ).append( "[" ).append( i ).append( "]  " ).append( messages.get( i ) ).append(
+                NEWLINE );
         }
 
         return message.toString();

maven-compat/src/main/java/org/apache/maven/repository/metadata/ClasspathContainer.java

@@ -129,12 +129,12 @@ implements Iterable<ArtifactMetadata>
     public String toString()
     {
         StringBuilder sb = new StringBuilder( 256 );
-        sb.append( "[scope=" + scope.getScope() );
+        sb.append( "[scope=" ).append( scope.getScope() );
         if ( classpath != null )
         {
             for ( ArtifactMetadata md : classpath )
             {
-                sb.append( ": " + md.toString() + '{' + md.getArtifactUri() + '}' );
+                sb.append( ": " ).append( md.toString() ).append( '{' ).append( md.getArtifactUri() ).append( '}' );
             }
         }
         sb.append( ']' );

maven-compat/src/main/java/org/apache/maven/repository/metadata/MetadataGraph.java

@@ -485,13 +485,13 @@ public class MetadataGraph
         }
         for ( MetadataGraphVertex v : vertices )
         {
-            sb.append( "Vertex:  " + v.getMd().toString() + "\n" );
+            sb.append( "Vertex:  " ).append( v.getMd().toString() ).append( "\n" );
             List<MetadataGraphEdge> ins = getIncidentEdges( v );
             if ( ins != null )
             {
                 for ( MetadataGraphEdge e : ins )
                 {
-                    sb.append( "       from :  " + e.toString() + "\n" );
+                    sb.append( "       from :  " ).append( e.toString() ).append( "\n" );
                 }
             }
             else
@@ -504,7 +504,7 @@ public class MetadataGraph
             {
                 for ( MetadataGraphEdge e : outs )
                 {
-                    sb.append( "        to :  " + e.toString() + "\n" );
+                    sb.append( "        to :  " ).append( e.toString() ).append( "\n" );
                 }
             }
             else

maven-compat/src/main/java/org/apache/maven/repository/metadata/MetadataGraphVertex.java

@@ -192,17 +192,17 @@ public class MetadataGraphVertex
             return super.hashCode();
         }
         StringBuilder hashString = new StringBuilder( 128 );
-        hashString.append( md.groupId + "|" );
+        hashString.append( md.groupId ).append( "|" );
-        hashString.append( md.artifactId + "|" );
+        hashString.append( md.artifactId ).append( "|" );
 
         if ( compareVersion )
         {
-            hashString.append( md.version + "|" );
+            hashString.append( md.version ).append( "|" );
         }
 
         if ( compareScope )
         {
-            hashString.append( md.getArtifactScope() + "|" );
+            hashString.append( md.getArtifactScope() ).append( "|" );
         }
 
         return hashString.toString().hashCode();

maven-core/src/main/java/org/apache/maven/plugin/PluginParameterException.java

@@ -144,8 +144,8 @@ public class PluginParameterException
             String alias = param.getAlias();
             if ( StringUtils.isNotEmpty( alias ) && !alias.equals( param.getName() ) )
             {
-                messageBuffer.append(
+                messageBuffer.append( "\n\n-OR-\n\n<configuration>\n  ...\n  <" ).append( alias ).append(
-                    "\n\n-OR-\n\n<configuration>\n  ...\n  <" + alias + ">VALUE</" + alias + ">\n</configuration>\n" );
+                    ">VALUE</" ).append( alias ).append( ">\n</configuration>\n" );
             }
         }
 

maven-embedder/src/main/java/org/apache/maven/cli/CLIReportingUtils.java

@@ -55,13 +55,14 @@ public final class CLIReportingUtils
         version.append( createMavenVersionString( properties ) ).append( LS );
         version.append( reduce( properties.getProperty( "distributionShortName" ) + " home: "
                             + System.getProperty( "maven.home", "<unknown maven home>" ) ) ).append( LS );
-        version.append( "Java version: " + System.getProperty( "java.version", "<unknown java version>" )
+        version.append( "Java version: " ).append(
-                            + ", vendor: " + System.getProperty( "java.vendor", "<unknown vendor>" ) ).append( LS );
+            System.getProperty( "java.version", "<unknown java version>" ) ).append( ", vendor: " ).append(
-        version.append( "Java home: " + System.getProperty( "java.home", "<unknown java home>" ) ).append( LS );
+            System.getProperty( "java.vendor", "<unknown vendor>" ) ).append( LS );
-        version.append( "Default locale: " + Locale.getDefault() + ", platform encoding: "
+        version.append( "Java home: " ).append( System.getProperty( "java.home", "<unknown java home>" ) ).append( LS );
-                            + System.getProperty( "file.encoding", "<unknown encoding>" ) ).append( LS );
+        version.append( "Default locale: " ).append( Locale.getDefault() ).append( ", platform encoding: " ).append(
-        version.append( "OS name: \"" + Os.OS_NAME + "\", version: \"" + Os.OS_VERSION + "\", arch: \"" + Os.OS_ARCH
+            System.getProperty( "file.encoding", "<unknown encoding>" ) ).append( LS );
-            + "\", family: \"" + Os.OS_FAMILY + "\"" );
+        version.append( "OS name: \"" ).append( Os.OS_NAME ).append( "\", version: \"" ).append( Os.OS_VERSION ).append(
+            "\", arch: \"" ).append( Os.OS_ARCH ).append( "\", family: \"" ).append( Os.OS_FAMILY ).append( "\"" );
         return version.toString();
     }
 

maven-embedder/src/test/java/org/apache/maven/cli/CLIManagerTest.java

@@ -70,7 +70,7 @@ public class CLIManagerTest
         for ( Option option : new CLIManagerExtension().getOptions() )
         {
             a = !a;
-            sb.append( "<tr class='" + ( a ? 'a' : 'b' ) + "'><td><code>-<a name='" );
+            sb.append( "<tr class='" ).append( a ? 'a' : 'b' ).append( "'><td><code>-<a name='" );
             sb.append( option.getOpt() );
             sb.append( "'>" );
             sb.append( option.getOpt() );