INT-3850: Fix SpEL usage in the CacheWritingMH

JIRA: https://jira.spring.io/browse/INT-3850

**Cherry-pick to 4.1.x, 4.0.x, 3.0.x**

spring-integration-gemfire/src/test/java/org/springframework/integration/gemfire/outbound/CacheWritingMessageHandlerTests.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.gemfire.outbound;
 
 import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
 
 import java.util.Collections;
 import java.util.HashMap;
@@ -24,10 +25,15 @@ import java.util.Map;
 
 import org.junit.Test;
 
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.data.gemfire.CacheFactoryBean;
 import org.springframework.data.gemfire.RegionFactoryBean;
+import org.springframework.expression.Expression;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.integration.expression.ValueExpression;
 import org.springframework.integration.support.MessageBuilder;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.support.GenericMessage;
 
 import com.gemstone.gemfire.cache.Cache;
 import com.gemstone.gemfire.cache.Region;
@@ -37,6 +43,7 @@ import com.gemstone.gemfire.cache.Region;
  * @author David Turanski
  * @author Gunnar Hillert
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 2.1
  */
 public class CacheWritingMessageHandlerTests {
@@ -51,7 +58,11 @@ public class CacheWritingMessageHandlerTests {
 		regionFactoryBean.afterPropertiesSet();
 		Region<String, String> region = regionFactoryBean.getObject();
 		assertEquals(0, region.size());
+
 		CacheWritingMessageHandler handler = new CacheWritingMessageHandler(region);
+		handler.setBeanFactory(mock(BeanFactory.class));
+		handler.afterPropertiesSet();
+
 		Map<String, String> map = new HashMap<String, String>();
 		map.put("foo", "bar");
 		Message<?> message = MessageBuilder.withPayload(map).build();
@@ -61,14 +72,15 @@ public class CacheWritingMessageHandlerTests {
 	}
 
 	@Test
+	@SuppressWarnings("unchecked")
 	public void ExpressionsWriteToCache() throws Exception {
 		CacheFactoryBean cacheFactoryBean = new CacheFactoryBean();
 		Cache cache = cacheFactoryBean.getObject();
-		RegionFactoryBean<String, String> regionFactoryBean = new RegionFactoryBean<String, String>() {};
+		RegionFactoryBean<String, Object> regionFactoryBean = new RegionFactoryBean<String, Object>() {};
 		regionFactoryBean.setName("test.expressionsWriteToCache");
 		regionFactoryBean.setCache(cache);
 		regionFactoryBean.afterPropertiesSet();
-		Region<String, String> region = regionFactoryBean.getObject();
+		Region<String, Object> region = regionFactoryBean.getObject();
 		assertEquals(0, region.size());
 		CacheWritingMessageHandler handler = new CacheWritingMessageHandler(region);
 
@@ -76,12 +88,23 @@ public class CacheWritingMessageHandlerTests {
 		expressions.put("'foo'", "'bar'");
 		expressions.put("payload.toUpperCase()", "headers['bar'].toUpperCase()");
 		handler.setCacheEntries(expressions);
+		handler.setBeanFactory(mock(BeanFactory.class));
+		handler.afterPropertiesSet();
 
-		Message<?> message = MessageBuilder.withPayload("foo").copyHeaders(Collections.singletonMap("bar", "bar")).build();
+		Message<?> message = MessageBuilder.withPayload("foo")
+				.copyHeaders(Collections.singletonMap("bar", "bar"))
+				.build();
 		handler.handleMessage(message);
 		assertEquals(2, region.size());
 		assertEquals("BAR", region.get("FOO"));
 		assertEquals("bar", region.get("foo"));
+
+		handler.setCacheEntryExpressions(Collections.<Expression, Expression>singletonMap(new LiteralExpression("baz"),
+				new ValueExpression<Long>(10L)));
+
+		handler.handleMessage(new GenericMessage<String>("test"));
+		assertEquals(3, region.size());
+		assertEquals(10L, region.get("baz"));
 	}
 
 }

spring-integration-gemfire/src/test/java/org/springframework/integration/gemfire/outbound/GemfireOutboundChannelAdapterTests-context.xml

@@ -8,19 +8,24 @@
 		http://www.springframework.org/schema/gemfire http://www.springframework.org/schema/gemfire/spring-gemfire.xsd
 		http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd
 		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
-	
+
 	<gfe:cache />
+
 	<gfe:replicated-region id="region1"/>
-	
+
 	<gfe:replicated-region id="region2"/>
-	
+
 	<int-gfe:outbound-channel-adapter id="cacheChannel1" region="region1"/>
-	
+
+	<bean id="bar" class="java.lang.String">
+		<constructor-arg value="bar"/>
+	</bean>
+
 	<int-gfe:outbound-channel-adapter id="cacheChannel2" region="region2" order="19">
 		<int-gfe:cache-entries>
-			<entry key="payload.toUpperCase()" value="payload.toLowerCase()"/> 
-			<entry key="'foo'" value="'bar'"/> 
-		</int-gfe:cache-entries>		 
+			<entry key="payload.toUpperCase()" value="payload.toLowerCase()"/>
+			<entry key="'foo'" value="@bar"/>
+		</int-gfe:cache-entries>
 	</int-gfe:outbound-channel-adapter>
 
 	<int:chain input-channel="cacheChainChannel">