CAMEL-10567: Camel-Jackson: Add an option to allow the UnmarshallType header use

Author: oscerd

components/camel-jackson/src/main/java/org/apache/camel/component/jackson/JacksonDataFormat.java

@@ -68,6 +68,7 @@ public class JacksonDataFormat extends ServiceSupport implements DataFormat, Dat
     private String enableFeatures;
     private String disableFeatures;
     private boolean enableJacksonTypeConverter;
+    private boolean allowJacksonUnmarshallType;
 
     /**
      * Use the default Jackson {@link ObjectMapper} and {@link Map}
@@ -158,7 +159,10 @@ public Object unmarshal(Exchange exchange, InputStream stream) throws Exception
 
         // is there a header with the unmarshal type?
         Class<?> clazz = unmarshalType;
-        String type = exchange.getIn().getHeader(JacksonConstants.UNMARSHAL_TYPE, String.class);
+        String type = null;
+        if (allowJacksonUnmarshallType) {
+            type = exchange.getIn().getHeader(JacksonConstants.UNMARSHAL_TYPE, String.class);
+        }
         if (type == null && isAllowJmsType()) {
             type = exchange.getIn().getHeader("JMSType", String.class);
         }
@@ -326,6 +330,19 @@ public boolean isEnableJacksonTypeConverter() {
     public void setEnableJacksonTypeConverter(boolean enableJacksonTypeConverter) {
         this.enableJacksonTypeConverter = enableJacksonTypeConverter;
     }
+    
+    public boolean isAllowJacksonUnmarshallType() {
+        return allowJacksonUnmarshallType;
+    }
+
+    /**
+     * If enabled then Jackson is allowed to attempt to use the CamelJacksonUnmarshalType header during the unmarshalling.
+     * <p/>
+     * This should only be enabled when desired to be used.
+     */
+    public void setAllowJacksonUnmarshallType(boolean allowJacksonUnmarshallType) {
+        this.allowJacksonUnmarshallType = allowJacksonUnmarshallType;
+    }
 
     public String getEnableFeatures() {
         return enableFeatures;

components/camel-jackson/src/test/java/org/apache/camel/component/jackson/JacksonMarshalUnmarshalTypeHeaderNotAllowedTest.java

@@ -0,0 +1,54 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.camel.component.jackson;
+
+import java.util.LinkedHashMap;
+
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.component.mock.MockEndpoint;
+import org.apache.camel.test.junit4.CamelTestSupport;
+import org.junit.Test;
+
+public class JacksonMarshalUnmarshalTypeHeaderNotAllowedTest extends CamelTestSupport {
+
+    @Test
+    public void testUnmarshalPojo() throws Exception {
+        MockEndpoint mock = getMockEndpoint("mock:reversePojo");
+        mock.expectedMessageCount(1);
+        mock.message(0).body().isInstanceOf(LinkedHashMap.class);
+
+        String json = "{\"name\":\"Camel\"}";
+        template.sendBodyAndHeader("direct:backPojo", json, JacksonConstants.UNMARSHAL_TYPE, TestPojo.class.getName());
+
+        assertMockEndpointsSatisfied();
+    }
+
+    @Override
+    protected RouteBuilder createRouteBuilder() throws Exception {
+        return new RouteBuilder() {
+
+            @Override
+            public void configure() throws Exception {
+                JacksonDataFormat format = new JacksonDataFormat();
+
+                from("direct:backPojo").unmarshal(format).to("mock:reversePojo");
+
+            }
+        };
+    }
+
+}

components/camel-jackson/src/test/java/org/apache/camel/component/jackson/JacksonMarshalUnmarshalTypeHeaderTest.java

@@ -46,6 +46,7 @@ protected RouteBuilder createRouteBuilder() throws Exception {
             @Override
             public void configure() throws Exception {
                 JacksonDataFormat format = new JacksonDataFormat();
+                format.setAllowJacksonUnmarshallType(true);
 
                 from("direct:backPojo").unmarshal(format).to("mock:reversePojo");