INT-681, INT-710, INT-1181 The <service-activator> element now supports an "expression" attribute as an alternative to "ref" + "method". Added ServiceActivatorFactoryBean, modified parser, updated schema, added ServiceActivator constructor to accept expression string, and provided some basic tests.

spring-integration-core/src/test/java/org/springframework/integration/config/xml/ServiceActivatorParserTests-context.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans:beans xmlns="http://www.springframework.org/schema/integration"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xmlns:beans="http://www.springframework.org/schema/beans"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans
+			http://www.springframework.org/schema/beans/spring-beans.xsd
+			http://www.springframework.org/schema/integration
+			http://www.springframework.org/schema/integration/spring-integration.xsd">
+
+	<service-activator input-channel="literalExpressionInput" expression="'foo'"/>
+
+	<service-activator input-channel="beanAsTargetInput" expression="@testBean.caps(payload)"/>
+
+	<service-activator input-channel="beanAsArgumentInput" expression="payload.getSimpleClassName(@testBean)"/>
+
+	<service-activator input-channel="beanInvocationResultInput" expression="payload.concat(@testBean.caps('foo'))"/>
+
+	<beans:bean id="testBean" class="org.springframework.integration.config.xml.ServiceActivatorParserTests$TestBean"/>
+
+</beans:beans>

spring-integration-core/src/test/java/org/springframework/integration/config/xml/ServiceActivatorParserTests.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2002-2010 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.config.xml;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.integration.core.MessageChannel;
+import org.springframework.integration.gateway.SimpleMessagingGateway;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * @author Mark Fisher
+ * @since 2.0
+ */
+@ContextConfiguration
+@RunWith(SpringJUnit4ClassRunner.class)
+public class ServiceActivatorParserTests {
+
+	@Autowired
+	private MessageChannel literalExpressionInput;
+
+	@Autowired
+	private MessageChannel beanAsTargetInput;
+
+	@Autowired
+	private MessageChannel beanAsArgumentInput;
+
+	@Autowired
+	private MessageChannel beanInvocationResultInput;
+
+
+	@Test
+	public void literalExpression() {
+		Object result = this.sendAndReceive(literalExpressionInput, "hello");
+		assertEquals("foo", result);
+	}
+
+	@Test
+	public void beanAsTarget() {
+		Object result = this.sendAndReceive(beanAsTargetInput, "hello");
+		assertEquals("HELLO", result);
+	}
+
+	@Test
+	public void beanAsArgument() {
+		Object result = this.sendAndReceive(beanAsArgumentInput, new TestPayload());
+		assertEquals("TestBean", result);
+	}
+
+	@Test
+	public void beanInvocationResult() {
+		Object result = this.sendAndReceive(beanInvocationResultInput, "hello");
+		assertEquals("helloFOO", result);
+	}
+
+
+	private Object sendAndReceive(MessageChannel channel, Object payload) {
+		SimpleMessagingGateway gateway = new SimpleMessagingGateway();
+		gateway.setRequestChannel(channel);
+		return gateway.sendAndReceive(payload);
+	}
+
+
+	@SuppressWarnings("unused")
+	private static class TestBean {
+
+		public String caps(String s) {
+			return s.toUpperCase();
+		}
+	}
+
+
+	@SuppressWarnings("unused")
+	private static class TestPayload {
+
+		public String getSimpleClassName(Object o) {
+			return o.getClass().getSimpleName();
+		}
+	}
+
+}