Added AbstractMailMessageTransformer.

org.springframework.integration.mail/src/main/java/org/springframework/integration/mail/transformer/AbstractMailMessageTransformer.java

@@ -0,0 +1,106 @@
+/*
+ * 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.mail.transformer;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.mail.Address;
+import javax.mail.Message.RecipientType;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.integration.adapter.MessageMappingException;
+import org.springframework.integration.mail.MailHeaders;
+import org.springframework.integration.message.Message;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.integration.message.MessagingException;
+import org.springframework.integration.transformer.Transformer;
+import org.springframework.util.Assert;
+
+/**
+ * Base class for Transformers that convert from a JavaMail Message to a
+ * Spring Integration Message.
+ * 
+ * @author Mark Fisher
+ */
+public abstract class AbstractMailMessageTransformer<T> implements Transformer {
+
+	protected final Log logger = LogFactory.getLog(this.getClass());
+
+
+	public Message<?> transform(Message<?> message) {
+		Object payload = message.getPayload();
+		if (payload != null && payload instanceof javax.mail.Message) {
+			try {
+				javax.mail.Message mailMessage = (javax.mail.Message) payload;
+				MessageBuilder<T> builder = this.doTransform(mailMessage);
+				if (builder != null) {
+					builder.copyHeaders(this.extractHeaderMapFromMailMessage(mailMessage));
+					message = builder.build();
+				}
+			}
+			catch (Exception e) {
+				throw new MessageMappingException(message, "failed to transform MailMessage", e);
+			}
+		}
+		else if (logger.isDebugEnabled()) {
+			logger.debug("unable to transform Message " + message);
+		}
+		return message;
+	}
+
+	protected abstract MessageBuilder<T> doTransform(javax.mail.Message mailMessage) throws Exception;
+
+
+	private Map<String, Object> extractHeaderMapFromMailMessage(javax.mail.Message mailMessage) {
+		try {
+			Map<String, Object> headers = new HashMap<String, Object>();
+			headers.put(MailHeaders.FROM, this.convertToString(mailMessage.getFrom()));
+			headers.put(MailHeaders.BCC, this.convertToStringArray(mailMessage.getRecipients(RecipientType.BCC)));
+			headers.put(MailHeaders.CC, this.convertToStringArray(mailMessage.getRecipients(RecipientType.CC)));
+			headers.put(MailHeaders.TO, this.convertToStringArray(mailMessage.getRecipients(RecipientType.TO)));
+			headers.put(MailHeaders.REPLY_TO, this.convertToString(mailMessage.getReplyTo()));
+			headers.put(MailHeaders.SUBJECT, mailMessage.getSubject());
+			return headers;
+		}
+		catch (Exception e) {
+			throw new MessagingException("conversion of MailMessage headers failed", e);
+		}
+	}
+
+	private String convertToString(Address[] addresses) {
+		if (addresses == null || addresses.length == 0) {
+			return null;
+		}
+		Assert.state(addresses.length == 1, "expected a single value but received an Array");
+		return addresses[0].toString();
+	}
+
+	private String[] convertToStringArray(Address[] addresses) {
+		if (addresses != null) {
+			String[] addressStrings = new String[addresses.length];
+			for (int i = 0; i < addresses.length; i++) {
+				addressStrings[i] = addresses[i].toString();
+			}
+			return addressStrings;
+		}
+		return new String[0];
+	}
+
+}