Make sure, duplicated Content-Type Headers are removed

Author: Chris Wiechmann

src/main/java/com/axway/apim/openapi/validator/Utils.java

@@ -2,7 +2,9 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.Iterator;
+import java.util.Map;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -102,4 +104,21 @@ public static Collection<String> getHeaderValues(HeaderSet headers, String name)
 		}
 		return result;
     }
+    
+    /**
+     * @param headers that might contain a duplicated Content-Type header
+     */
+    public static void removeDuplicateContentTypeHeader(HeaderSet headers) {
+    	HeaderEntry contentTypeHeader = headers.getHeaderEntry("Content-Type");
+    	if(contentTypeHeader != null && contentTypeHeader.size()>1) {
+    		traceMessage("WARN - Header: Multiple Content-Type headers found. Remove all but the first header.", TraceLevel.DEBUG);
+    		// Get the first header
+    		Header first = contentTypeHeader.get(0);
+    		// Clear all others
+    		contentTypeHeader.clear();
+    		// Add only one header
+    		contentTypeHeader.add(first);
+    	}
+    	return;
+    }
 }

src/test/java/com/axway/apim/openapi/validator/UtilsTest.java

@@ -6,6 +6,8 @@
 import org.testng.annotations.Test;
 import org.testng.reporters.Files;
 
+import com.vordel.mime.HeaderSet;
+
 public class UtilsTest {
 
 	private static final String TEST_PACKAGE = "com/axway/apim/openapi/validator/";
@@ -23,4 +25,15 @@ public void testGetContentStartLongContent() throws IOException {
 		String payloadStart = Utils.getContentStart(payload, 40, true);
 		Assert.assertEquals(payloadStart, "[  {    \"id\": 13973,    \"category\": {   ...(truncated)");
 	}
+	
+	@Test
+	public void testRemoveDuplicateContentTypeHeader() throws IOException {
+    	HeaderSet headers = new HeaderSet();
+    	headers.addHeader("content-Type", "application/json");
+    	headers.addHeader("Content-type", "application/xml");
+    	Assert.assertEquals(headers.getHeadersSize("Content-Type"), 2);
+    	Utils.removeDuplicateContentTypeHeader(headers);
+    	Assert.assertEquals(headers.getHeadersSize("Content-Type"), 1);
+    	Assert.assertEquals(headers.getHeader("Content-Type"), "application/json");
+	}
 }