DROOLS-1437 Avoid stax-utils dependency by performing manual indentation

kie-dmn-backend/pom.xml

@@ -42,16 +42,6 @@
       <artifactId>xmlunit-core</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>net.java.dev.stax-utils</groupId>
-      <artifactId>stax-utils</artifactId>
-      <exclusions>
-        <exclusion>
-        <groupId>com.bea.xml</groupId>
-        <artifactId>jsr173-ri</artifactId>
-        </exclusion>
-      </exclusions>
-    </dependency>
 
     <dependency>
       <groupId>org.slf4j</groupId>

kie-dmn-backend/src/main/java/org/kie/dmn/backend/marshalling/CustomStaxReader.java

@@ -12,9 +12,9 @@
 
 
 public class CustomStaxReader extends StaxReader {
-
     /** 
-     * ATTENTION use read-only methods do not mutate
+     * ATTENTION this is intercepted during XStream StaxDriver creation as there is no proper API to inherit.
+     * Do not mutate reference - mutating this reference would not sort any effect on the actual underlying StaxReader
      */
     private XMLStreamReader in;
 

kie-dmn-backend/src/main/java/org/kie/dmn/backend/marshalling/CustomStaxWriter.java

@@ -3,17 +3,24 @@
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamWriter;
 
+import com.thoughtworks.xstream.io.StreamException;
 import com.thoughtworks.xstream.io.naming.NameCoder;
 import com.thoughtworks.xstream.io.xml.QNameMap;
 import com.thoughtworks.xstream.io.xml.StaxWriter;
 
 
 public class CustomStaxWriter extends StaxWriter {
     /** 
-     * ATTENTION use read-only methods do not mutate
+     * ATTENTION this is intercepted during XStream StaxDriver creation as there is no proper API to inherit.
+     * Do not mutate reference - mutating this reference would not sort any effect on the actual underlying StaxWriter
      */
     private XMLStreamWriter out;
-
+    private int tagDepth = 0;
+    private static enum Op {
+        START_NODE, END_NODE, VALUE;
+    }
+    private Op lastOp = null;
+
     public CustomStaxWriter(QNameMap qnameMap, XMLStreamWriter out, boolean writeStartEndDocument, boolean repairingNamespace, NameCoder nameCoder) throws XMLStreamException {
         super(qnameMap, out, writeStartEndDocument, repairingNamespace, nameCoder);
         this.out = out;
@@ -26,4 +33,50 @@ public void writeNamespace(String prefix, String uri) throws XMLStreamException
     public void setDefaultNamespace(String uri) throws XMLStreamException {
         out.setDefaultNamespace(uri);
     }
+
+    @Override
+    public void endNode() {
+        if ( this.lastOp == Op.END_NODE ) {
+            try {
+                out.writeCharacters( System.lineSeparator() );
+                for ( int i = 0; i < (tagDepth-1); i++ ) { out.writeCharacters("  "); }
+            } catch (XMLStreamException e) {
+                throw new StreamException(e);
+            }
+        }
+        super.endNode();
+        --this.tagDepth;
+
+        this.lastOp = Op.END_NODE;
+
+        if ( this.tagDepth == 0 ) {
+            // closed last element before EOF
+            try {
+                out.writeCharacters( System.lineSeparator() );
+            } catch (XMLStreamException e) {
+                throw new StreamException(e);
+            }
+        }
+    }
+
+    @Override
+    public void startNode(String arg0) {
+        try {
+            out.writeCharacters( System.lineSeparator() );
+            for ( int i = 0; i < tagDepth; i++ ) { out.writeCharacters("  "); }
+        } catch (XMLStreamException e) {
+            throw new StreamException(e);
+        }
+        super.startNode(arg0);
+        ++this.tagDepth;
+
+        this.lastOp = Op.START_NODE;
+    }
+
+    @Override
+    public void setValue(String text) {
+        super.setValue(text);
+
+        this.lastOp = Op.VALUE;
+    }
 }

kie-dmn-backend/src/main/java/org/kie/dmn/backend/marshalling/v1_1/xstream/XStreamMarshaller.java

@@ -20,11 +20,8 @@
 import com.thoughtworks.xstream.io.xml.AbstractPullReader;
 import com.thoughtworks.xstream.io.xml.QNameMap;
 import com.thoughtworks.xstream.io.xml.StaxDriver;
-import com.thoughtworks.xstream.io.xml.StaxReader;
 import com.thoughtworks.xstream.io.xml.StaxWriter;
 
-import javanet.staxutils.StaxUtilsXMLOutputFactory;
-
 import org.kie.dmn.feel.model.v1_1.Artifact;
 import org.kie.dmn.feel.model.v1_1.Association;
 import org.kie.dmn.feel.model.v1_1.AuthorityRequirement;
@@ -71,7 +68,6 @@
 import java.io.*;
 
 import javax.xml.namespace.QName;
-import javax.xml.stream.XMLOutputFactory;
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.XMLStreamWriter;
@@ -95,18 +91,6 @@ public class XStreamMarshaller
 //        qmap.registerMapping(new javax.xml.namespace.QName("http://www.omg.org/spec/FEEL/20140401", "feel", "feel"), "dddecision"); // FIXME still not sure how to output non-used ns like 'feel:'
 
         staxDriver = new StaxDriver() {
-
-            private XMLOutputFactory outputFactory = null;
-
-            public XMLOutputFactory getOutputFactory() {
-                if (outputFactory == null) {
-                    XMLOutputFactory factory = new StaxUtilsXMLOutputFactory(super.getOutputFactory());
-                    factory.setProperty(StaxUtilsXMLOutputFactory.INDENTING, Boolean.TRUE);
-                    outputFactory = factory;
-                }
-                return outputFactory;
-            }
-
             public AbstractPullReader createStaxReader(XMLStreamReader in) {
                 return new CustomStaxReader(getQnameMap(), in);
             }