AMQP-741: Fix Headers Containing Arrays

JIRA: https://jira.spring.io/browse/AMQP-741

The `DefaultMessagePropertiesConverter` incorrectly converts headers
containing arrays (e.g. `String[]`) `toString()`.

The java client handles arrays in headers.

Change the converter to allow arrays to pass down to the client
(after converting the element values if necessary).

Fix Unit Test

Since we don't actually go through rabbit in this test,
the converted properties are still `Object[]`.

Author: garyrussell

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/support/DefaultMessagePropertiesConverter.java

@@ -185,10 +185,18 @@ private Object convertHeaderValueIfNecessary(Object value) {
 				|| (value instanceof LongString) || (value instanceof Integer) || (value instanceof Long)
 				|| (value instanceof Float) || (value instanceof Double) || (value instanceof BigDecimal)
 				|| (value instanceof Short) || (value instanceof Byte) || (value instanceof Date)
-				|| (value instanceof List) || (value instanceof Map);
+				|| (value instanceof List) || (value instanceof Map) || (value instanceof Object[]);
 		if (!valid && value != null) {
 			value = value.toString();
 		}
+		else if (value instanceof Object[]) {
+			Object[] array = (Object[]) value;
+			Object[] writableArray = new Object[array.length];
+			for (int i = 0; i < writableArray.length; i++) {
+				writableArray[i] = convertHeaderValueIfNecessary(array[i]);
+			}
+			value = writableArray;
+		}
 		else if (value instanceof List<?>) {
 			List<Object> writableList = new ArrayList<Object>(((List<?>) value).size());
 			for (Object listValue : (List<?>) value) {

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/core/RabbitTemplateIntegrationTests.java

@@ -21,6 +21,7 @@
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.startsWith;
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -409,9 +410,21 @@ public void testSendToNonExistentAndThenReceive() throws Exception {
 
 	@Test
 	public void testSendAndReceiveWithPostProcessor() throws Exception {
+		final String[] strings = new String[] { "1", "2" };
 		template.convertAndSend(ROUTE, (Object) "message", message -> {
 			message.getMessageProperties().setContentType("text/other");
 			// message.getMessageProperties().setUserId("foo");
+			MessageProperties props = message.getMessageProperties();
+			props.getHeaders().put("strings", strings);
+			props.getHeaders().put("objects", new Object[] { new Foo(), new Foo() });
+			props.getHeaders().put("bytes", "abc".getBytes());
+			return message;
+		});
+		template.setAfterReceivePostProcessors(message -> {
+			assertEquals(Arrays.asList(strings), message.getMessageProperties().getHeaders().get("strings"));
+			assertEquals(Arrays.asList(new String[] { "FooAsAString", "FooAsAString" }),
+					message.getMessageProperties().getHeaders().get("objects"));
+			assertArrayEquals("abc".getBytes(), (byte[]) message.getMessageProperties().getHeaders().get("bytes"));
 			return message;
 		});
 		String result = (String) template.receiveAndConvert(ROUTE);
@@ -1559,4 +1572,17 @@ public ConnectionFactory defaultCF() {
 
 	}
 
+	private static class Foo {
+
+		Foo() {
+			super();
+		}
+
+		@Override
+		public String toString() {
+			return "FooAsAString";
+		}
+
+	}
+
 }

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/support/DefaultMessagePropertiesConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -17,6 +17,7 @@
 package org.springframework.amqp.rabbit.support;
 
 import static org.hamcrest.Matchers.instanceOf;
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
@@ -192,12 +193,30 @@ public void testFromUnsupportedValueInMap() {
 	public void testInboundDeliveryMode() {
 		DefaultMessagePropertiesConverter converter = new DefaultMessagePropertiesConverter();
 		MessageProperties props = new MessageProperties();
+		String[] strings = new String[] { "1", "2" };
+		props.getHeaders().put("strings", strings);
+		props.getHeaders().put("objects", new Object[] { new Foo() });
 		props.setDeliveryMode(MessageDeliveryMode.NON_PERSISTENT);
 		BasicProperties bProps = converter.fromMessageProperties(props, "UTF-8");
 		assertEquals(MessageDeliveryMode.toInt(MessageDeliveryMode.NON_PERSISTENT), bProps.getDeliveryMode().intValue());
 		props = converter.toMessageProperties(bProps, null, "UTF-8");
 		assertEquals(MessageDeliveryMode.NON_PERSISTENT, props.getReceivedDeliveryMode());
+		assertArrayEquals(strings, (Object[]) props.getHeaders().get("strings"));
+		assertEquals("[FooAsAString]", Arrays.asList((Object[]) props.getHeaders().get("objects")).toString());
 		assertNull(props.getDeliveryMode());
 	}
 
+	private static class Foo {
+
+		Foo() {
+			super();
+		}
+
+		@Override
+		public String toString() {
+			return "FooAsAString";
+		}
+
+	}
+
 }