[bugfix] Allow XDM Array and Map types to be serialized over the XML:DB API

Closes eXist-db/exist#4919

Author: adamretter

exist-core/src/main/java/org/exist/xmldb/LocalXMLResource.java

@@ -137,7 +137,11 @@ else if (root != null && !(root instanceof NodeValue)) {
         } else if (value != null) {
             try {
                 if (Type.subTypeOf(value.getType(),Type.STRING)) {
-                    return ((StringValue)value).getStringValue(true);
+                    return ((StringValue) value).getStringValue(true);
+
+                } else if (Type.subTypeOf(value.getType(), Type.MAP_ITEM) || Type.subTypeOf(value.getType(), Type.ARRAY_ITEM)) {
+                    return value.toString();
+
                 } else {
                     return value.getStringValue();
                 }

exist-core/src/main/java/org/exist/xmlrpc/RpcConnection.java

@@ -1818,6 +1818,10 @@ private Map<String, Object> queryResultToRpcResponse(final long startTime, final
                             entry.add(String.valueOf(((NodeImpl) next).getNodeNumber()));
                         }
                         result.add(entry);
+
+                    } else if (Type.subTypeOf(next.getType(), Type.MAP_ITEM) || Type.subTypeOf(next.getType(), Type.ARRAY_ITEM)) {
+                        result.add(next.toString());
+
                     } else {
                         result.add(next.getStringValue());
                     }
@@ -1982,7 +1986,14 @@ private Map<String, String> atomicMap(final Item item) throws XPathException {
 
         final int type = item.getType();
         result.put("type", Type.getTypeName(type));
-        result.put("value", item.getStringValue());
+
+        final String value;
+        if (Type.subTypeOf(item.getType(), Type.MAP_ITEM) || Type.subTypeOf(item.getType(), Type.ARRAY_ITEM)) {
+            value = item.toString();
+        } else {
+            value = item.getStringValue();
+        }
+        result.put("value", value);
 
         return result;
     }

exist-core/src/main/java/org/exist/xquery/functions/array/ArrayType.java

@@ -489,11 +489,37 @@ public String toString() {
             builder.append(' ');
         }
         for (int i = 0; i < vector.length(); i++) {
-            final Sequence value = vector.nth(i);
-            builder.append(value.toString());
-            if (i < vector.length() - 1) {
+
+            if (i > 0) {
                 builder.append(", ");
             }
+
+            final Sequence sequence = vector.nth(i);
+
+            if (!sequence.hasOne()) {
+                builder.append('(');
+            }
+
+            for (int j = 0; j < sequence.getItemCount(); j++) {
+                if (j > 0) {
+                    builder.append(", ");
+                }
+
+                final Item item = sequence.itemAt(j);
+                if (Type.subTypeOf(item.getType(), Type.STRING)) {
+                    builder.append('"');
+                }
+
+                builder.append(item.toString());
+
+                if (Type.subTypeOf(item.getType(), Type.STRING)) {
+                    builder.append('"');
+                }
+            }
+
+            if (!sequence.hasOne()) {
+                builder.append(')');
+            }
         }
         if (vector.length() > 0) {
             builder.append(' ');

exist-core/src/test/java/org/exist/xmldb/SerializationTest.java

@@ -242,6 +242,30 @@ public void getXmlDeclYes() throws XMLDBException {
 		}
 	}
 
+	@Test
+	public void testArray() throws XMLDBException {
+		final String query = "array { \"value 1\", \"value 2\" }";
+
+		final XQueryService service = testCollection.getService(XQueryService.class);
+		final ResourceSet result = service.query(query);
+		assertEquals(1, result.getSize());
+
+		final Resource resource = result.getResource(0);
+		assertEquals("[ \"value 1\", \"value 2\" ]", resource.getContent());
+	}
+
+	@Test
+	public void testMap() throws XMLDBException {
+		final String query = "map { \"prop1\" : \"value 1\", \"prop2\" : \"value 2\" }";
+
+		final XQueryService service = testCollection.getService(XQueryService.class);
+		final ResourceSet result = service.query(query);
+		assertEquals(1, result.getSize());
+
+		final Resource resource = result.getResource(0);
+		assertEquals("map {\"prop2\": \"value 2\", \"prop1\": \"value 1\"}", resource.getContent());
+	}
+
 	private static void assertXMLEquals(final String expected, final Resource actual) throws XMLDBException {
 		final Source srcExpected = Input.fromString(expected).build();
 		final Source srcActual = Input.fromString(actual.getContent().toString()).build();