Preserve HTTP parameter order

Signed-off-by: Richard Ogin <rogin@users.noreply.github.com>

Author: rogin

server/src/com/mirth/connect/util/HttpUtil.java

@@ -11,7 +11,7 @@
 
 import java.nio.charset.Charset;
 import java.util.ArrayList;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -104,7 +104,7 @@ public static Map<String, List<String>> getTableMap(boolean useVariable, String
     }
 
     public static Map<String, List<String>> getTableMap(String mapVariable, MessageMaps messageMaps, ConnectorMessage connectorMessage) {
-        Map<String, List<String>> map = new HashMap<String, List<String>>();
+        Map<String, List<String>> map = new LinkedHashMap<String, List<String>>();
 
         try {
             Map<?, ?> source = (Map<?, ?>) messageMaps.get(mapVariable, connectorMessage);

server/test/com/mirth/connect/util/HttpUtilTest.java

@@ -9,10 +9,13 @@
 
 package com.mirth.connect.util;
 
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.fail;
 
 import java.security.KeyStore;
+import java.util.LinkedHashMap;
+import java.util.Map;
 import java.util.UUID;
 
 import javax.net.ssl.SSLContext;
@@ -22,6 +25,9 @@
 import org.apache.http.ssl.SSLContexts;
 import org.junit.Test;
 
+import com.mirth.connect.donkey.model.message.ConnectorMessage;
+import com.mirth.connect.donkey.util.MessageMaps;
+
 public class HttpUtilTest {
 
     @Test
@@ -40,4 +46,20 @@ public void testExecuteGetRequest() throws Exception {
         } catch (Exception e) {
         }
     }
+
+    @Test
+    public void testMapOrderPreserved() throws Exception {
+        final String MAP_KEY = "MyMap";
+
+        Map<String, Object> initial = new LinkedHashMap<>();
+        initial.put("First", 1);
+        initial.put("Second", 2);
+        initial.put("Third", 3);
+
+        ConnectorMessage cm = new ConnectorMessage();
+        cm.getSourceMap().put(MAP_KEY, initial);
+
+        Map<String, ?> copied = HttpUtil.getTableMap(MAP_KEY, new MessageMaps(), cm);
+        assertArrayEquals("Failed to preserve key order", initial.keySet().toArray(), copied.keySet().toArray());
+    }
 }