Preload email files during greenmail start (issue #250)

Added example for loading EML files

docs/index.html

@@ -1134,6 +1134,12 @@ <h4>How can I let GreenMail dynamically choose available port?</h4>
     greenMail.getSmtp().getServerSetup());
 </code></pre><!-- @formatter:on -->
 
+                <h4>How can I pre-load an existing (eml) message?</h4>
+                <p>You can load an existing electronic mail (eml) messsage and store the message for a user in a mailbox folder.</p>
+                <p>
+                    Example: 
+                    <a href="https://github.com/greenmail-mail-test/greenmail/blob/master/greenmail-core/src/test/java/com/icegreen/greenmail/examples/ExamplePreloadMailFromFsTest.java">ExamplePreloadMailFromFsTest.java</a>
+                    </p>
             </section>
 
             <section id="download" class="anchor">

greenmail-core/src/test/java/com/icegreen/greenmail/examples/ExamplePreloadMailFromFsTest.java

@@ -0,0 +1,60 @@
+package com.icegreen.greenmail.examples;
+
+import com.icegreen.greenmail.imap.ImapHostManager;
+import com.icegreen.greenmail.junit.GreenMailRule;
+import com.icegreen.greenmail.user.GreenMailUser;
+import com.icegreen.greenmail.user.UserManager;
+import com.icegreen.greenmail.util.ServerSetupTest;
+import jakarta.mail.Message;
+import jakarta.mail.Session;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ExamplePreloadMailFromFsTest {
+    @Rule
+    public final GreenMailRule greenMail = new GreenMailRule(ServerSetupTest.SMTP);
+    public static final String EML_FILE_NAME = ExamplePreloadMailFromFsTest.class.getName() + ".eml";
+
+    @Test
+    public void testPreloadMailFromFs() throws Exception {
+        final Session session = greenMail.getSmtp().createSession();
+
+        // Create test data
+        final MimeMessage msg = new MimeMessage(session);
+        msg.setRecipient(Message.RecipientType.TO, new InternetAddress("foo@localhost"));
+        msg.setFrom("bar@localhost");
+        msg.setSubject("Hello");
+        msg.setText("Test message saved as eml (electronic mail format, aka internet message format)");
+        try (FileOutputStream os = new FileOutputStream(EML_FILE_NAME)) {
+            msg.writeTo(os);
+        }
+
+        // Load msg from file system
+        final ImapHostManager imapHostManager = greenMail.getManagers().getImapHostManager();
+        final UserManager userManager = greenMail.getManagers().getUserManager();
+        final GreenMailUser user = userManager.createUser("foo@localhost", "foo-login", "secret");
+        try (InputStream source = Files.newInputStream(Paths.get(EML_FILE_NAME))) {
+            final MimeMessage loadedMsg = new MimeMessage(session, source);
+            imapHostManager.getFolder(user, "INBOX").store(loadedMsg);
+        }
+
+        // Verify
+        final MimeMessage[] receivedMessages = greenMail.getReceivedMessages();
+        assertThat(receivedMessages).hasSize(1);
+        final MimeMessage receivedMessage = receivedMessages[0];
+        assertThat(receivedMessage.getSubject()).isEqualTo(msg.getSubject());
+        assertThat(receivedMessage.getContent()).isEqualTo(msg.getContent());
+        assertThat(receivedMessage.getFrom()).isEqualTo(msg.getFrom());
+        assertThat(receivedMessage.getRecipients(Message.RecipientType.TO))
+            .isEqualTo(msg.getRecipients(Message.RecipientType.TO));
+    }
+}

greenmail-core/src/test/java/com/icegreen/greenmail/test/specificmessages/EncodingTest.java

@@ -1,20 +1,19 @@
 package com.icegreen.greenmail.test.specificmessages;
 
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
-import jakarta.mail.*;
-import jakarta.mail.internet.*;
-
 import com.icegreen.greenmail.junit.GreenMailRule;
 import com.icegreen.greenmail.util.EncodingUtil;
 import com.icegreen.greenmail.util.GreenMailUtil;
 import com.icegreen.greenmail.util.ServerSetupTest;
 import com.sun.mail.imap.IMAPStore;
+import jakarta.mail.*;
+import jakarta.mail.internet.*;
 import org.junit.Rule;
 import org.junit.Test;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -44,15 +43,15 @@ public void testTextPlainWithUTF8() throws MessagingException, IOException {
 
         MimeBodyPart html = new MimeBodyPart();
         html.setContent(MimeUtility.encodeText("<!doctype html>" +
-                "<html lang=en>" +
-                "<head>" +
-                "<meta charset=utf-8>" +
-                "<title>Title with Umlaut \u00FC</title>" +
-                "</head>" +
-                "<body>" +
-                "<p>8BIT Content with umlaut ü</p>" +
-                "</body>" +
-                "</html>", "UTF-8", "B"), "text/html; charset=utf-8");
+            "<html lang=en>" +
+            "<head>" +
+            "<meta charset=utf-8>" +
+            "<title>Title with Umlaut \u00FC</title>" +
+            "</head>" +
+            "<body>" +
+            "<p>8BIT Content with umlaut ü</p>" +
+            "</body>" +
+            "</html>", "UTF-8", "B"), "text/html; charset=utf-8");
         html.setHeader("Content-Transfer-Encoding", "8BIT");
         multipart.addBodyPart(html);
 
@@ -84,7 +83,6 @@ public void testTextPlainWithUTF8() throws MessagingException, IOException {
             inboxFolder.open(Folder.READ_WRITE);
             Message[] messages = inboxFolder.getMessages();
             MimeMessage msg = (MimeMessage) messages[0];
-            message.writeTo(new FileOutputStream("t.eml"));
             assertThat(msg.getContentType().startsWith("multipart/alternative")).isTrue();
             Multipart multipartReceived = (Multipart) msg.getContent();
 
@@ -124,7 +122,7 @@ public void testTextPlainWithUTF8AndGreenMailApi() throws MessagingException, IO
 
         MimeMessage msg = greenMail.getReceivedMessages()[0];
         assertThat(msg.getSubject()).isEqualTo(subject);
-        assertThat(msg.getContentType()).isEqualTo( "text/plain; charset=UTF-8");
+        assertThat(msg.getContentType()).isEqualTo("text/plain; charset=UTF-8");
         assertThat(msg.getContent()).isEqualTo(content);
     }
 }