Merge remote-tracking branch 'aduprat/MAILET-110'

mailet/standard/src/main/java/org/apache/james/transport/mailets/ContentReplacer.java

@@ -0,0 +1,147 @@
+/****************************************************************
+ * Licensed to the Apache Software Foundation (ASF) under one   *
+ * or more contributor license agreements.  See the NOTICE file *
+ * distributed with this work for additional information        *
+ * regarding copyright ownership.  The ASF licenses this file   *
+ * to you 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.apache.james.transport.mailets;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.List;
+import java.util.regex.Matcher;
+
+import javax.mail.MessagingException;
+import javax.mail.internet.ContentType;
+import javax.mail.internet.ParseException;
+
+import org.apache.mailet.Mail;
+import org.apache.mailet.MailetException;
+import org.apache.mailet.base.GenericMailet;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Strings;
+
+public class ContentReplacer {
+
+    private final boolean debug;
+    private final GenericMailet logOwner;
+
+    public ContentReplacer(boolean debug, GenericMailet logOwner) {
+        this.debug = debug;
+        this.logOwner = logOwner;
+    }
+
+    public String applyPatterns(List<ReplacingPattern> patterns, String text) {
+        String textCopy = new String(text);
+        for (ReplacingPattern replacingPattern : patterns) {
+            textCopy = applyPattern(replacingPattern, textCopy);
+        }
+        return textCopy;
+    }
+
+    private String applyPattern(ReplacingPattern replacingPattern, String text) {
+        boolean changed;
+        int index = 0;
+        do {
+            changed = false;
+            Matcher matcher = replacingPattern.getMatcher().matcher(text);
+            if (matcher.find(index)) {
+                text = replaceFirst(replacingPattern, matcher);
+                changed = true;
+                index++;
+            }
+        } while (shouldRepeat(replacingPattern, changed));
+        return text;
+    }
+
+    private String replaceFirst(ReplacingPattern replacingPattern, Matcher matcher) {
+        if (debug) {
+            logOwner.log("Subject rule match: " + replacingPattern.getMatcher());
+        }
+        return matcher.replaceFirst(replacingPattern.getSubstitution());
+    }
+
+    private boolean shouldRepeat(ReplacingPattern replacingPattern, boolean changed) {
+        return replacingPattern.isRepeat() && changed;
+    }
+
+    public void replaceMailContentAndSubject(Mail mail, ReplaceConfig replaceConfig, Optional<Charset> charset) throws MailetException {
+        try {
+            boolean subjectChanged = applySubjectReplacingUnits(mail, replaceConfig, charset);
+            boolean contentChanged = applyBodyReplacingUnits(mail, replaceConfig, charset);
+
+            if (subjectChanged || contentChanged) {
+                mail.getMessage().saveChanges();
+            }
+        } catch (MessagingException e) {
+            throw new MailetException("Error in replace", e);
+
+        } catch (IOException e) {
+            throw new MailetException("Error in replace", e);
+        }
+    }
+
+    private boolean applySubjectReplacingUnits(Mail mail, ReplaceConfig replaceConfig, Optional<Charset> charset) throws MessagingException {
+        if (!replaceConfig.getSubjectReplacingUnits().isEmpty()) {
+            String subject = applyPatterns(replaceConfig.getSubjectReplacingUnits(), 
+                    Strings.nullToEmpty(mail.getMessage().getSubject()));
+            if (charset.isPresent()) {
+                mail.getMessage().setSubject(subject, charset.get().name());
+                return true;
+            }
+            else {
+                String previousCharset = previousCharset(mail);
+                mail.getMessage().setSubject(subject, previousCharset);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private String previousCharset(Mail mail) throws ParseException, MessagingException {
+        ContentType contentType = new ContentType(mail.getMessage().getContentType());
+        return contentType.getParameter("Charset");
+    }
+
+    private boolean applyBodyReplacingUnits(Mail mail, ReplaceConfig replaceConfig, Optional<Charset> charset) throws IOException, MessagingException, ParseException {
+        if (!replaceConfig.getBodyReplacingUnits().isEmpty()) {
+            Object bodyObj = mail.getMessage().getContent();
+            if (bodyObj instanceof String) {
+                String body = applyPatterns(replaceConfig.getBodyReplacingUnits(), 
+                        Strings.nullToEmpty((String) bodyObj));
+                setContent(mail, body, charset);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void setContent(Mail mail, String body, Optional<Charset> charset) throws MessagingException, ParseException {
+        mail.getMessage().setContent(body, getContentType(mail, charset));
+    }
+
+    private String getContentType(Mail mail, Optional<Charset> charset) throws MessagingException, ParseException {
+        String contentTypeAsString = mail.getMessage().getContentType();
+        if (charset.isPresent()) {
+            ContentType contentType = new ContentType(contentTypeAsString);
+            contentType.setParameter("charset", charset.get().name());
+            return contentType.toString();
+        }
+        return contentTypeAsString;
+    }
+
+}