support for setting parameters and output properties on transformer instances used by the XsltPayloadTransformer

resolves INT-897

org.springframework.integration.xml/src/main/java/org/springframework/integration/xml/transformer/DefaultTransformerConfigurer.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.integration.xml.transformer;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.xml.transform.Transformer;
+
+import org.springframework.integration.core.Message;
+import org.springframework.integration.core.MessageHeaders;
+
+import sun.tools.tree.OrExpression;
+
+/**
+ * {@link TransformerConfigurer} instance which looks for headers and uses them
+ * to configure the provided {@link Transformer} instance. For example a header
+ * names xslt_paramter_X will cause the transfomer to be configured with a
+ * property names X with the value of the header. A property named
+ * xslt_output_property_X will cause an output property on the transformer to be
+ * set with this headers value.
+ * 
+ * 
+ * @author Jonas Partner
+ * 
+ */
+public class DefaultTransformerConfigurer implements TransformerConfigurer {
+
+	public void configureTransfomer(Message<?> message, Transformer transformer) {
+		Map<String,Object> parameters = extractParameterHeaders(message.getHeaders());
+		for(String paramName: parameters.keySet()){
+			transformer.setParameter(paramName, parameters.get(paramName));
+		}
+		
+		Map<String, String> outputProperties = extractOutputPropertyHeaders(message.getHeaders());
+		for(String outputPropertyName : outputProperties.keySet()){
+			transformer.setOutputProperty(outputPropertyName, outputProperties.get(outputPropertyName));
+		}
+		
+	}
+
+	protected Map<String, String> extractOutputPropertyHeaders(
+			MessageHeaders headers) {
+		Map<String, String> parameters = new HashMap<String, String>();
+		int prefixStringLength = XsltHeaders.OUTPUT_PROPERTY.length();
+		for (String key : headers.keySet()) {
+			if (key.startsWith(XsltHeaders.OUTPUT_PROPERTY)) {
+				Object headerValue = headers.get(key);
+				if (!(headerValue instanceof String)) {
+					throw new IllegalArgumentException(
+							"Xslt Transfomer only support String output properties received header of type"
+									+ headerValue.getClass().getName()
+									+ " for header named " + key);
+				}
+				parameters.put(key.substring(prefixStringLength), (String)headerValue);
+			}
+		}
+		return parameters;
+	}
+
+	protected Map<String, Object> extractParameterHeaders(MessageHeaders headers) {
+		Map<String, Object> parameters = new HashMap<String, Object>();
+		int prefixStringLength = XsltHeaders.PARAMATER.length();
+		for (String key : headers.keySet()) {
+			if (key.startsWith(XsltHeaders.PARAMATER)) {
+				parameters.put(key.substring(prefixStringLength), headers.get(key));
+			}
+		}
+		return parameters;
+	}
+
+}

org.springframework.integration.xml/src/main/java/org/springframework/integration/xml/transformer/TransformerConfigurer.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.xml.transformer;
+
+import javax.xml.transform.Transformer;
+
+import org.springframework.integration.core.Message;
+
+/**
+ * Allows customistation of the transformer based on the recevied message prior
+ * to transformation
+ * 
+ * @author Jonas Partner
+ * 
+ */
+public interface TransformerConfigurer {
+
+	/**
+	 * Callback method called by Xslt transfomer implementations after transformer is creates
+	 * @param message
+	 * @param transformer
+	 */
+	public void configureTransfomer(Message<?> message, Transformer transformer);
+
+}

org.springframework.integration.xml/src/main/java/org/springframework/integration/xml/transformer/XsltHeaders.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.xml.transformer;
+
+import javax.xml.transform.Transformer;
+
+/**
+ * Message headers that can be used to configure the {@link Transformer}
+ * instance used for Xsl transformation
+ * 
+ * @author Jonas Partner
+ * 
+ */
+public abstract class XsltHeaders {
+
+	public static final String PREFIX = "xslt_";
+	
+	public static final String OUTPUT_PROPERTY = PREFIX +  "output_property_";
+	
+	public static final String PARAMATER = PREFIX +  "parameter_";
+	
+	
+
+}

org.springframework.integration.xml/src/main/java/org/springframework/integration/xml/transformer/XsltPayloadTransformer.java

@@ -20,6 +20,7 @@ import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.transform.Result;
 import javax.xml.transform.Source;
 import javax.xml.transform.Templates;
+import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerException;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMResult;
@@ -29,8 +30,10 @@ import javax.xml.transform.stream.StreamSource;
 import org.w3c.dom.Document;
 
 import org.springframework.core.io.Resource;
+import org.springframework.integration.core.Message;
 import org.springframework.integration.core.MessagingException;
 import org.springframework.integration.transformer.AbstractPayloadTransformer;
+import org.springframework.integration.transformer.AbstractTransformer;
 import org.springframework.integration.xml.result.DomResultFactory;
 import org.springframework.integration.xml.result.ResultFactory;
 import org.springframework.integration.xml.source.DomSourceFactory;
@@ -64,7 +67,7 @@ import java.io.IOException;
  * @author Jonas Partner
  * @author Mark Fisher
  */
-public class XsltPayloadTransformer extends AbstractPayloadTransformer<Object, Object> {
+public class XsltPayloadTransformer extends AbstractTransformer {
 
     private final Templates templates;
 
@@ -75,6 +78,8 @@ public class XsltPayloadTransformer extends AbstractPayloadTransformer<Object, O
     private volatile ResultFactory resultFactory = new DomResultFactory();
 
     private volatile boolean alwaysUseSourceResultFactories = false;
+    
+    private volatile TransformerConfigurer transformerConfigurer;
 
 
     public XsltPayloadTransformer(Templates templates) throws ParserConfigurationException {
@@ -141,32 +146,34 @@ public class XsltPayloadTransformer extends AbstractPayloadTransformer<Object, O
         this.alwaysUseSourceResultFactories = alwaysUserSourceResultFactories;
     }
 
-    @Override
-    public Object transformPayload(Object payload) throws TransformerException {
+	@Override
+	protected Object doTransform(Message<?> message) throws Exception {
+		Transformer transformer = buildTransformer(message);
+		Object payload = message.getPayload();
         Object transformedPayload = null;
         if (this.alwaysUseSourceResultFactories) {
-            transformedPayload = transformUsingFactories(payload);
+            transformedPayload = transformUsingFactories(payload, transformer);
         } else if (payload instanceof String) {
-            transformedPayload = transformString((String) payload);
+            transformedPayload = transformString((String) payload, transformer);
         } else if (payload instanceof Document) {
-            transformedPayload = transformDocument((Document) payload);
+            transformedPayload = transformDocument((Document) payload, transformer);
         } else if (payload instanceof Source) {
-            transformedPayload = transformSource((Source) payload, payload);
+            transformedPayload = transformSource((Source) payload, payload, transformer);
         } else {
             // fall back to trying factories
-            transformedPayload = transformUsingFactories(payload);
+            transformedPayload = transformUsingFactories(payload, transformer);
         }
         return transformedPayload;
     }
 
-    protected Object transformUsingFactories(Object payload) throws TransformerException {
+    protected Object transformUsingFactories(Object payload, Transformer transformer) throws TransformerException {
         Source source = sourceFactory.createSource(payload);
-        return transformSource(source, payload);
+        return transformSource(source, payload, transformer);
     }
 
-    protected Object transformSource(Source source, Object payload) throws TransformerException {
+    protected Object transformSource(Source source, Object payload, Transformer transformer) throws TransformerException {
         Result result = resultFactory.createResult(payload);
-        this.templates.newTransformer().transform(source, result);
+        transformer.transform(source, result);
 
         if (resultTransformer != null) {
             return resultTransformer.transformResult(result);
@@ -174,14 +181,14 @@ public class XsltPayloadTransformer extends AbstractPayloadTransformer<Object, O
         return result;
     }
 
-    protected String transformString(String stringPayload) throws TransformerException {
+    protected String transformString(String stringPayload, Transformer transformer) throws TransformerException {
         StringResult result = new StringResult();
-        this.templates.newTransformer().transform(
+        transformer.transform(
                 new StringSource(stringPayload), result);
         return result.toString();
     }
 
-    protected Document transformDocument(Document documentPayload) throws TransformerException {
+    protected Document transformDocument(Document documentPayload, Transformer transformer) throws TransformerException {
         DOMSource source = new DOMSource(documentPayload);
         Result result = resultFactory.createResult(documentPayload);
         if (!DOMResult.class.isAssignableFrom(result.getClass())) {
@@ -189,8 +196,19 @@ public class XsltPayloadTransformer extends AbstractPayloadTransformer<Object, O
                     "Document to Document conversion requires a DOMResult-producing ResultFactory implementation");
         }
         DOMResult domResult = (DOMResult) result;
-        this.templates.newTransformer().transform(source, domResult);
+        
+        transformer.transform(source, domResult);
         return (Document) domResult.getNode();
     }
+    
+    protected Transformer buildTransformer(Message<?> message) throws TransformerException{
+    	Transformer transformer = this.templates.newTransformer();
+    	if(this.transformerConfigurer != null){
+    		this.transformerConfigurer.configureTransfomer(message, transformer);
+    	}
+    	return transformer;
+    }
+
+
 
 }