diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformer.java b/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformer.java new file mode 100644 index 0000000000..c4e68b2f10 --- /dev/null +++ b/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformer.java @@ -0,0 +1,30 @@ +/* + * 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.transformer; + +import java.util.Map; + +/** + * A strategy interface for modifying the header values of a message. + * + * @author Mark Fisher + */ +public interface HeaderTransformer { + + void transform(Map headers); + +} diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformingMessageHandler.java b/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformingMessageHandler.java new file mode 100644 index 0000000000..f1eb65b2ed --- /dev/null +++ b/org.springframework.integration/src/main/java/org/springframework/integration/transformer/HeaderTransformingMessageHandler.java @@ -0,0 +1,56 @@ +/* + * 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.transformer; + +import java.util.HashMap; +import java.util.Map; + +import org.springframework.integration.handler.MessageHandler; +import org.springframework.integration.message.Message; +import org.springframework.integration.message.MessageBuilder; +import org.springframework.integration.message.MessagingException; +import org.springframework.util.Assert; + +/** + * A {@link MessageHandler} implementation that delegates to an instance + * of the {@link HeaderTransformer} strategy interface to modify the + * header values of a {@link Message}. + * + * @author Mark Fisher + */ +public class HeaderTransformingMessageHandler implements MessageHandler { + + private final HeaderTransformer transformer; + + + public HeaderTransformingMessageHandler(HeaderTransformer transformer) { + Assert.notNull(transformer, "transformer must not be null"); + this.transformer = transformer; + } + + + public Message handle(Message message) { + try { + Map headerMap = new HashMap(message.getHeaders()); + this.transformer.transform(headerMap); + return MessageBuilder.fromPayload(message.getPayload()).copyHeaders(headerMap).build(); + } catch (Exception e) { + throw new MessagingException(message, "failed to transform message headers", e); + } + } + +} diff --git a/org.springframework.integration/src/test/java/org/springframework/integration/transformer/HeaderTransformingMessageHandlerTests.java b/org.springframework.integration/src/test/java/org/springframework/integration/transformer/HeaderTransformingMessageHandlerTests.java new file mode 100644 index 0000000000..a60f045bde --- /dev/null +++ b/org.springframework.integration/src/test/java/org/springframework/integration/transformer/HeaderTransformingMessageHandlerTests.java @@ -0,0 +1,74 @@ +/* + * 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.transformer; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertNull; + +import java.util.Map; + +import org.junit.Test; + +import org.springframework.integration.message.Message; +import org.springframework.integration.message.MessageBuilder; + +/** + * @author Mark Fisher + */ +public class HeaderTransformingMessageHandlerTests { + + @Test + public void addHeader() { + HeaderTransformer transformer = new HeaderTransformer() { + public void transform(Map headers) { + headers.put("header2", "baz"); + } + }; + HeaderTransformingMessageHandler handler = new HeaderTransformingMessageHandler(transformer); + Message message = MessageBuilder.fromPayload("foo").setHeader("header1", "bar").build(); + Message result = handler.handle(message); + assertEquals("bar", result.getHeaders().get("header1")); + assertEquals("baz", result.getHeaders().get("header2")); + } + + @Test + public void replaceHeader() { + HeaderTransformer transformer = new HeaderTransformer() { + public void transform(Map headers) { + headers.put("header1", "baz"); + } + }; + HeaderTransformingMessageHandler handler = new HeaderTransformingMessageHandler(transformer); + Message message = MessageBuilder.fromPayload("foo").setHeader("header1", "bar").build(); + Message result = handler.handle(message); + assertEquals("baz", result.getHeaders().get("header1")); + } + + @Test + public void removeHeader() { + HeaderTransformer transformer = new HeaderTransformer() { + public void transform(Map headers) { + headers.remove("header1"); + } + }; + HeaderTransformingMessageHandler handler = new HeaderTransformingMessageHandler(transformer); + Message message = MessageBuilder.fromPayload("foo").setHeader("header1", "bar").build(); + Message result = handler.handle(message); + assertNull(result.getHeaders().get("header1")); + } + +}