Adding conditional logic to pull out root cause to a couple diagnosers.

git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@320918 13f79535-47bb-0310-9956-ffa450edef68

maven-core/src/main/java/org/apache/maven/usability/ArtifactResolverDiagnoser.java

@@ -21,6 +21,8 @@ import org.apache.maven.artifact.resolver.ArtifactResolutionException;
 import org.apache.maven.usability.diagnostics.DiagnosisUtils;
 import org.apache.maven.usability.diagnostics.ErrorDiagnoser;
 
+import java.io.IOException;
+
 public class ArtifactResolverDiagnoser
     implements ErrorDiagnoser
 {
@@ -43,6 +45,13 @@ public class ArtifactResolverDiagnoser
         message.append( "\n\n" );
         message.append( exception.getMessage() );
         
+        IOException ioe = (IOException) DiagnosisUtils.getFromCausality( exception, IOException.class );
+        
+        if ( ioe != null && exception.getMessage().indexOf( ioe.getMessage() ) < 0 )
+        {
+            message.append( "\n\nCaused by I/O exception: " ).append( ioe.getMessage() );
+        }
+
         if ( !wagonManager.isOnline() )
         {
             message.append( "\n" ).append( SystemWarnings.getOfflineWarning() );

maven-core/src/main/java/org/apache/maven/usability/MojoExecutionExceptionDiagnoser.java

@@ -56,6 +56,22 @@ public class MojoExecutionExceptionDiagnoser
             message.append( "\n\n" ).append( longMessage );
         }
         
+        Throwable directCause = mee.getCause();
+        
+        if ( directCause != null )
+        {
+            message.append( "\n" );
+            
+            String directCauseMessage = directCause.getMessage();
+            
+            if ( directCauseMessage != null && mee.getMessage().indexOf( directCauseMessage ) < 0 )
+            {
+                message.append( "\nEmbedded error: " ).append( directCauseMessage );
+            }
+            
+            DiagnosisUtils.appendRootCauseIfPresentAndUnique( directCause, message, false );
+        }
+
         return message.toString();
     }
 

maven-error-diagnostics/src/main/java/org/apache/maven/usability/diagnostics/DiagnosisUtils.java

@@ -77,4 +77,24 @@ public final class DiagnosisUtils
         
         return null;
     }
+
+    public static void appendRootCauseIfPresentAndUnique( Throwable error, StringBuffer message, boolean includeTypeInfo )
+    {
+        Throwable root = DiagnosisUtils.getRootCause( error );
+        
+        if ( root != null && root != error )
+        {
+            String rootMsg = root.getMessage();
+            
+            if ( rootMsg != null && error.getMessage().indexOf(rootMsg) < 0 )
+            {
+                message.append( "\nRoot message: " ).append( rootMsg );
+                
+                if ( includeTypeInfo )
+                {
+                    message.append( "\nRoot error type: " ).append( root.getClass().getName() );
+                }
+            }
+        }
+    }
 }

maven-error-diagnostics/src/main/java/org/apache/maven/usability/diagnostics/ErrorDiagnostics.java

@@ -129,6 +129,10 @@ public class ErrorDiagnostics
 
             message.append( error.getMessage() );
             
+            message.append( "\nError type: " ).append( error.getClass().getName() );
+            
+            DiagnosisUtils.appendRootCauseIfPresentAndUnique( error, message, true );
+
             return message.toString();
         }