Added Sloppy XML printing

src/main/java/net/vhati/modmanager/core/SloppyXMLOutputProcessor.java

@@ -0,0 +1,157 @@
+package net.vhati.modmanager.core;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.util.List;
+
+import org.jdom2.Attribute;
+import org.jdom2.Content;
+import org.jdom2.Document;
+import org.jdom2.Element;
+import org.jdom2.Namespace;
+import org.jdom2.output.Format;
+import org.jdom2.output.XMLOutputter;
+import org.jdom2.output.support.AbstractXMLOutputProcessor;
+import org.jdom2.output.support.FormatStack;
+import org.jdom2.output.support.Walker;
+import org.jdom2.util.NamespaceStack;
+
+
+/**
+ * An XMLOutputProcessor that omits the root element.
+ *
+ * The root element will be invisible.
+ * The root's namespace declarations will still count.
+ * The root's immediate child content will not be indented.
+ *
+ * Adding namespace declarations to the root will prevent
+ * descendents from having an xmlns:prefix="uri" attribute.
+ *
+ * To use, construct an XMLOutputter with this as an arg.
+ * Then call outputter.output( doc, writer ).
+ *
+ * Or just call the static sloppyPrint() method below.
+ *
+ * @see org.jdom2.output.XMLOutputter
+ */
+public class SloppyXMLOutputProcessor extends AbstractXMLOutputProcessor {
+
+	// Copied from AbstractXMLOutputProcessor in JDOM 2.0.5, with modification.
+	@Override
+	protected void printElement( Writer out, FormatStack fstack, NamespaceStack nstack, Element element ) throws IOException {
+		nstack.push( element );
+		try {
+			final List<Content> content = element.getContent();
+
+			if ( !element.isRootElement() ) {
+				write( out, "<" );
+				write( out, element.getQualifiedName() );
+				for ( final Namespace ns : nstack.addedForward() ) {
+					printNamespace( out, fstack, ns );
+				}
+				if ( element.hasAttributes() ) {
+					for ( final Attribute attribute : element.getAttributes() ) {
+						printAttribute( out, fstack, attribute );
+					}
+				}
+
+				if ( content.isEmpty() ) {
+					if ( fstack.isExpandEmptyElements() ) {
+						write( out, "></" );
+						write( out, element.getQualifiedName() );
+						write( out, ">" );
+					} else {
+						write( out, " />" );
+					}
+					return;
+				}
+			}
+
+			if ( element.isRootElement() ) {
+				// Undo indention that comes with push().
+				String prevIndent = fstack.getLevelIndent();
+				fstack.push();
+				fstack.setLevelIndent( prevIndent );
+			}
+			else {
+				fstack.push();
+			}
+
+			try {
+				final String space = element.getAttributeValue( "space", Namespace.XML_NAMESPACE );
+				if ( "default".equals(space) ) {
+					fstack.setTextMode( fstack.getDefaultMode() );
+				}
+				else if ( "preserve".equals(space) ) {
+					fstack.setTextMode( Format.TextMode.PRESERVE );
+				}
+
+				Walker walker = buildWalker( fstack, content, true );
+				if ( !walker.hasNext() ) {
+					// The walker has formatted away whatever content we had.
+					// But there WAS content, so expand the tag.
+					// Omitted: />
+					if ( !element.isRootElement() ) {
+						write( out, "></" );
+						write( out, element.getQualifiedName() );
+						write( out, ">" );
+					}
+					return;
+				}
+				// We have some content.
+
+				if ( !element.isRootElement() ) {
+					write( out, ">" );
+				}
+
+				if ( !walker.isAllText() ) {
+					// We need to newline/indent.
+					textRaw( out, fstack.getPadBetween() );
+				}
+
+				printContent( out, fstack, nstack, walker );
+
+				if ( !walker.isAllText() ) {
+					// We need to newline/indent.
+					textRaw( out, fstack.getPadLast() );
+				}
+
+				if ( !element.isRootElement() ) {
+					write( out, "</" );
+					write( out, element.getQualifiedName() );
+					write( out, ">" );
+				}
+			}
+			finally {
+				fstack.pop();
+			}
+		}
+		finally {
+			nstack.pop();
+		}
+
+		// Technically, nstack.push(), super.printElement(), nstack.pop()
+		//   would do to make namespaces look already declared.
+		// But to avoid having to loop over root's child content to feed
+		//   XMLOutputter means writing most of this method just for
+		//   root (omitting the tag printing parts).
+		// And to expand tags that have blank content while still
+		//   trimming means writing the whole method (excluding root with
+		//   if blocks).
+	}
+
+
+	/**
+	 * Creates an outputter and writes an XML tree.
+	 */
+	public static void sloppyPrint( Document doc, Writer writer, String encoding ) throws IOException {
+		Format format = Format.getPrettyFormat();
+		format.setExpandEmptyElements( false );
+		format.setOmitDeclaration( false );
+
+		if ( encoding != null ) format.setEncoding( encoding );
+
+		XMLOutputter outputter = new XMLOutputter( format, new SloppyXMLOutputProcessor() );
+		outputter.output( doc, writer );
+	}
+}