#84 Add PomChangeParentVersion that preserves file formatting

butterfly-utilities/pom.xml

@@ -59,6 +59,11 @@
             <artifactId>xmlunit</artifactId>
             <version>1.5</version>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.woodstox</groupId>
+            <artifactId>woodstox-core</artifactId>
+            <version>5.0.3</version>
+        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>

butterfly-utilities/src/main/java/com/paypal/butterfly/utilities/operations/pom/AbstractArtifactPomOperation.java

@@ -154,9 +154,7 @@ public boolean equals(Object obj) {
 
     @Override
     public int hashCode() {
-        return hashCode(super.hashCode(),
-                groupId,
-                artifactId);
+        return hashCode(super.hashCode(), groupId, artifactId);
     }
 
 }

butterfly-utilities/src/main/java/com/paypal/butterfly/utilities/operations/pom/AbstractStaxArtifactPomOperation.java

@@ -0,0 +1,74 @@
+package com.paypal.butterfly.utilities.operations.pom;
+
+import com.paypal.butterfly.extensions.api.exception.TransformationDefinitionException;
+
+import java.util.Objects;
+
+/**
+ * Abstract Artifact POM operation.
+ *
+ * @author facarvalho
+ */
+public abstract class AbstractStaxArtifactPomOperation<T extends AbstractStaxArtifactPomOperation> extends AbstractStaxPomOperation<T> {
+
+    protected String groupId;
+    protected String artifactId;
+
+    public T setGroupId(String groupId) {
+        checkForBlankString("GroupId", groupId);
+        this.groupId = groupId;
+        return (T) this;
+    }
+
+    public T setArtifactId(String artifactId) {
+        checkForBlankString("ArtifactId",artifactId);
+        this.artifactId = artifactId;
+        return (T) this;
+    }
+
+    /**
+     * Set dependency group id and artifact id based on a String
+     * whose format is "groupId:artifactId". It throws a
+     * {@link TransformationDefinitionException} if the specified
+     * artifact String is invalid
+     *
+     * @param artifact the artifact formatted String
+     * @return this operation instance
+     */
+    public T setArtifact(String artifact) {
+        checkForBlankString("artifact", artifact);
+        String[] split = artifact.split(":");
+        if (split.length != 2) {
+            throw new TransformationDefinitionException("Invalid artifact " + artifact);
+        }
+        groupId = split[0];
+        artifactId = split[1];
+        return (T) this;
+    }
+
+    public String getGroupId() {
+        return groupId;
+    }
+
+    public String getArtifactId() {
+        return artifactId;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof AbstractStaxArtifactPomOperation)) return false;
+
+        AbstractStaxArtifactPomOperation tu = (AbstractStaxArtifactPomOperation) obj;
+        if (!Objects.equals(tu.groupId, this.groupId)) return false;
+        if (!Objects.equals(tu.artifactId, this.artifactId)) return false;
+
+        return super.equals(obj);
+    }
+
+    @Override
+    public int hashCode() {
+        return hashCode(super.hashCode(), groupId, artifactId);
+    }
+
+}

butterfly-utilities/src/main/java/com/paypal/butterfly/utilities/operations/pom/AbstractStaxPomOperation.java

@@ -0,0 +1,49 @@
+package com.paypal.butterfly.utilities.operations.pom;
+
+import com.paypal.butterfly.extensions.api.TOExecutionResult;
+import com.paypal.butterfly.extensions.api.TransformationContext;
+import com.paypal.butterfly.utilities.operations.pom.stax.AbstractStaxOperation;
+import org.apache.maven.model.Model;
+import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+/**
+ * Abstract POM operation.
+ *
+ * @author facarvalho
+ */
+abstract class AbstractStaxPomOperation<T extends AbstractStaxPomOperation> extends AbstractStaxOperation<T> {
+
+    /*
+     * Read the Maven pom file and returns an in-memory model of it
+     */
+    protected Model getModel(File pomFile) throws IOException, XmlPullParserException {
+        MavenXpp3Reader reader = new MavenXpp3Reader();
+        FileInputStream fileInputStream = new FileInputStream(pomFile);
+        Model model = reader.read(fileInputStream);
+        fileInputStream.close();
+
+        return model;
+    }
+
+    @Override
+    protected TOExecutionResult execution(File transformedAppFolder, TransformationContext transformationContext) {
+        return super.execution(transformedAppFolder, transformationContext);
+    }
+
+    @Override
+    protected TOExecutionResult xmlExecution(File transformedAppFolder, TransformationContext transformationContext) throws XmlPullParserException, XMLStreamException, IOException {
+        return pomExecution(transformedAppFolder, transformationContext);
+    }
+
+    /*
+     * This abstract method is supposed to be developed by the subclasses executing POM file operations
+     */
+    protected abstract TOExecutionResult pomExecution(File transformedAppFolder, TransformationContext transformationContext) throws XmlPullParserException, XMLStreamException, IOException;
+
+}

butterfly-utilities/src/main/java/com/paypal/butterfly/utilities/operations/pom/PomAddParent.java

@@ -1,10 +1,19 @@
 package com.paypal.butterfly.utilities.operations.pom;
 
 import com.paypal.butterfly.extensions.api.TOExecutionResult;
+import com.paypal.butterfly.extensions.api.TransformationContext;
 import com.paypal.butterfly.extensions.api.exception.TransformationOperationException;
 import com.paypal.butterfly.extensions.api.operations.AddElement;
-import org.apache.maven.model.Model;
+import com.paypal.butterfly.utilities.operations.pom.stax.EndElementEventCondition;
+import com.paypal.butterfly.utilities.operations.pom.stax.StartElementEventCondition;
 import org.apache.maven.model.Parent;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
+
+import javax.xml.stream.XMLEventReader;
+import javax.xml.stream.XMLEventWriter;
+import javax.xml.stream.XMLStreamException;
+import java.io.File;
+import java.io.IOException;
 
 /**
  * Add a parent artifact in a Maven POM file.
@@ -13,7 +22,7 @@
  *
  * @author facarvalho
  */
-public class PomAddParent extends AbstractArtifactPomOperation<PomAddParent> implements AddElement<PomAddParent> {
+public class PomAddParent extends AbstractStaxArtifactPomOperation<PomAddParent> implements AddElement<PomAddParent> {
 
     private static final String DESCRIPTION = "Add parent artifact %s:%s in POM file %s";
 
@@ -88,44 +97,78 @@ public String getDescription() {
     }
 
     @Override
-    protected TOExecutionResult pomExecution(String relativePomFile, Model model) {
+    protected TOExecutionResult pomExecution(File transformedAppFolder, TransformationContext transformationContext) throws XmlPullParserException, XMLStreamException, IOException {
+
+        File pomFile = getAbsoluteFile(transformedAppFolder, transformationContext);
+        Parent existingParent = getModel(pomFile).getParent();
         String details;
-        Parent existingParent = model.getParent();
+
+        String relativePomFile = getRelativePath(transformedAppFolder, pomFile);
 
         if (existingParent != null) {
-            String message = String.format("Pom file %s already has a parent", getRelativePath());
+            String message = String.format("Pom file %s already has a parent", relativePomFile);
 
             switch (ifPresent) {
                 case WarnNotAdd:
-                    return TOExecutionResult.warning(this, new TransformationOperationException(message));
+                    return TOExecutionResult.warning(this, message);
                 case NoOp:
                     return TOExecutionResult.noOp(this, message);
                 case Fail:
                     // Fail is the default
-                default:
                     return TOExecutionResult.error(this, new TransformationOperationException(message));
             }
         }
 
-        Parent newParent;
-        if(groupId != null && artifactId != null && version != null) {
-            newParent = new Parent();
-            newParent.setGroupId(groupId);
-            newParent.setArtifactId(artifactId);
-            newParent.setVersion(version);
-            model.setParent(newParent);
-        } else {
-            // FIXME this should be in a pre-validation
+        // FIXME this should be in a pre-validation
+        if(groupId == null && artifactId == null && version == null) {
             throw new IllegalStateException("Invalid POM parent transformation operation");
         }
 
+        XMLEventReader reader = getReader(transformedAppFolder, transformationContext);
+        XMLEventWriter writer = getWriter(transformedAppFolder, transformationContext);
+
+        if (existingParent != null && ifPresent.equals(IfPresent.WarnButAdd)) {
+            copyUntil(reader, writer, new StartElementEventCondition("parent"), true);
+            skipUntil(reader, new EndElementEventCondition("parent"));
+            writeNewParent(writer);
+            writer.add(eventFactory.createEndElement("", "","parent"));
+        } else {
+            copyUntil(reader, writer, new StartElementEventCondition("project"), true);
+            writer.add(eventFactory.createStartElement("", "", "parent"));
+            writeNewParent(writer);
+            writer.add(eventFactory.createEndElement("", "","parent"));
+        }
+
+        writer.add(reader);
+
+        Parent newParent = new Parent();
+        newParent.setGroupId(groupId);
+        newParent.setArtifactId(artifactId);
+        newParent.setVersion(version);
+
         if (ifPresent.equals(IfPresent.Overwrite)) {
-            details = String.format("Parent for POM file (%s) has been set to %s", relativePomFile, newParent);
+            details = String.format("Parent for POM file %s has been set to %s", relativePomFile, newParent);
             return TOExecutionResult.success(this, details);
         } else {
-            details = String.format("Parent for POM file (%s) has been overwritten to %s", relativePomFile, newParent);
+            details = String.format("Parent for POM file %s has been overwritten to %s", relativePomFile, newParent);
             return TOExecutionResult.warning(this, details);
         }
     }
 
+    private void writeNewParent(XMLEventWriter writer) throws XMLStreamException {
+
+        // FIXME
+        // Fix indentation
+
+        writer.add(eventFactory.createStartElement("", "", "groupId"));
+        writer.add(eventFactory.createCharacters(groupId));
+        writer.add(eventFactory.createEndElement("", "", "groupId"));
+        writer.add(eventFactory.createStartElement("", "", "artifactId"));
+        writer.add(eventFactory.createCharacters(artifactId));
+        writer.add(eventFactory.createEndElement("", "", "artifactId"));
+        writer.add(eventFactory.createStartElement("", "", "version"));
+        writer.add(eventFactory.createCharacters(version));
+        writer.add(eventFactory.createEndElement("", "", "version"));
+    }
+
 }

butterfly-utilities/src/main/java/com/paypal/butterfly/utilities/operations/pom/PomChangeParent.java

@@ -7,10 +7,12 @@
 import org.apache.maven.model.Parent;
 
 /**
- * Changes the parent, or its version, in a Maven POM file.
+ * This transformation utility is deprecated.
+ * Please use {@link PomAddParent} or {@link PomChangeParentVersion} instead.
  *
  * @author facarvalho
  */
+@Deprecated
 public class PomChangeParent extends AbstractArtifactPomOperation<PomChangeParent> implements ChangeOrRemoveElement<PomChangeParent> {
 
     private static final String DESCRIPTION = "Change parent artifact in POM file %s";