Added StaticHandlerMethodResolver.

org.springframework.integration/src/main/java/org/springframework/integration/handler/StaticHandlerMethodResolver.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2002-2008 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.handler;
+
+import java.lang.reflect.Method;
+
+import org.springframework.integration.core.Message;
+import org.springframework.util.Assert;
+
+/**
+ * An implementation of {@link HandlerMethodResolver} that always returns the
+ * same Method instance. Used when the exact Method is indicated explicitly
+ * or otherwise resolvable in advance based on static metadata.
+ * 
+ * @author Mark Fisher
+ */
+public class StaticHandlerMethodResolver implements HandlerMethodResolver {
+
+	private final Method method;
+
+
+	public StaticHandlerMethodResolver(Method method) {
+		Assert.notNull(method, "method must not be null");
+		Assert.notEmpty(method.getParameterTypes(),
+				"Message-handling method [" + method + "] must accept at least one parameter.");
+		Assert.isTrue(HandlerMethodUtils.isValidHandlerMethod(method),
+				"Invalid Message-handling method [" + method + "]");
+		this.method = method;
+	}
+
+
+	public Method resolveHandlerMethod(Message<?> message) {
+		return this.method;
+	}
+
+}

org.springframework.integration/src/test/java/org/springframework/integration/handler/StaticHandlerMethodResolverTests.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2002-2008 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.handler;
+
+import static org.junit.Assert.assertEquals;
+
+import java.lang.reflect.Method;
+import java.util.Map;
+
+import org.junit.Test;
+
+import org.springframework.integration.annotation.Header;
+import org.springframework.integration.annotation.Headers;
+import org.springframework.integration.message.StringMessage;
+
+/**
+ * @author Mark Fisher
+ */
+public class StaticHandlerMethodResolverTests {
+
+	@Test(expected = IllegalArgumentException.class)
+	public void methodDeclaredOnObjectIsNotValid() throws Exception {
+		Method method = Object.class.getDeclaredMethod("equals", new Class<?>[] {Object.class});
+		new StaticHandlerMethodResolver(method);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void noArgMethodIsNotValid() throws Exception {
+		Method method = TestBean.class.getDeclaredMethod("noArgMethod", new Class<?>[0]);
+		new StaticHandlerMethodResolver(method);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void privateMethodIsNotValid() throws Exception {
+		Method method = TestBean.class.getDeclaredMethod("privateMethod", new Class<?>[] {String.class});
+		new StaticHandlerMethodResolver(method);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void nullMethodIsNotValid() throws Exception {
+		new StaticHandlerMethodResolver(null);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void ambiguousMethodIsNotValid() throws Exception {
+		Class<?>[] types = new Class<?>[] { String.class, String.class };
+		Method method = TestBean.class.getDeclaredMethod("ambiguousMethod", types);
+		new StaticHandlerMethodResolver(method);
+	}
+
+	@Test
+	public void validPayloadMethod() throws Exception {
+		Method method = TestBean.class.getDeclaredMethod("payloadMethod", new Class<?>[] {String.class});
+		HandlerMethodResolver resolver = new StaticHandlerMethodResolver(method);
+		Method resolved = resolver.resolveHandlerMethod(new StringMessage("foo"));
+		assertEquals(method, resolved);
+	}
+
+	@Test
+	public void validHeaderMethod() throws Exception {
+		Method method = TestBean.class.getDeclaredMethod("headerMethod", new Class<?>[] {String.class});
+		HandlerMethodResolver resolver = new StaticHandlerMethodResolver(method);
+		Method resolved = resolver.resolveHandlerMethod(new StringMessage("foo"));
+		assertEquals(method, resolved);
+	}
+
+	@Test
+	public void validHeaderMapMethod() throws Exception {
+		Method method = TestBean.class.getDeclaredMethod("headerMapMethod", new Class<?>[] {Map.class});
+		HandlerMethodResolver resolver = new StaticHandlerMethodResolver(method);
+		Method resolved = resolver.resolveHandlerMethod(new StringMessage("foo"));
+		assertEquals(method, resolved);
+	}
+
+	@Test
+	public void validPayloadAndHeaderMethod() throws Exception {
+		Class<?>[] types = new Class<?>[] { String.class, String.class };
+		Method method = TestBean.class.getDeclaredMethod("payloadAndHeaderMethod", types);
+		HandlerMethodResolver resolver = new StaticHandlerMethodResolver(method);
+		Method resolved = resolver.resolveHandlerMethod(new StringMessage("foo"));
+		assertEquals(method, resolved);
+	}
+
+
+	public static class TestBean {
+
+		public void noArgMethod() {
+		}
+
+		@SuppressWarnings("unused")
+		private void privateMethod(String s) {
+		}
+
+		public void ambiguousMethod(String s1, String s2) {
+		}
+
+		public void payloadMethod(String s) {
+		}
+
+		public void headerMethod(@Header("test") String s) {
+		}
+
+		public void headerMapMethod(@Headers Map<String, Object> headerMap) {
+		}
+
+		public void payloadAndHeaderMethod(String s1, @Header("test") String s2) {
+		}
+	}
+
+}