Smtp server java mail

Saved searches

Use saved searches to filter your results more quickly

You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session. You switched accounts on another tab or window. Reload to refresh your session.

Simple SMTP server Java API

License

ctabin/smtp4j

This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Sign In Required

Please sign in to use Codespaces.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching Xcode

If nothing happens, download Xcode and try again.

Launching Visual Studio Code

Your codespace will open once ready.

There was a problem preparing your codespace, please try again.

Latest commit

Git stats

Files

Failed to load latest commit information.

README.md

Simple API to fake an SMTP server for Unit testing (and more).

This API is inspired from dumbster with the following improvements:

• Dynamic port lookup feature
• Support of MIME messages with attachments
• Up-to-date dependencies
• Extended tests
• Numerous bugfixes

Here is the compatibility map of this API:

Version	JDK	Package
	JDK 8 and upwards	javax
>= 2.0.0	JDK 11 and upwards	jakarta

Use the following dependency in your pom.xml :

dependency> groupId>ch.astormgroupId> artifactId>smtp4jartifactId> version>3.0.0version> dependency>

Here is a quick example of the usage of this API that shows an oversight on how it can be used:

/* SMTP server is started on port 1025 */ SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.withPort(1025).start()) < /* create and send an SMTP message to smtp4j */ MimeMessageBuilder messageBuilder = new MimeMessageBuilder(server); messageBuilder.from("source@smtp4j.local"). to("target1@smtp4j.local", "John Doe "). cc("target3@smtp4j.local"). subject("Hello, world !"). body("Hello\r\nGreetings from smtp4j !\r\n\r\nBye."); messageBuilder.send(); //uses Transport.send(. ) /* retrieve the sent message in smtp4j */ ListSmtpMessage> messages = server.readReceivedMessages(); assertEquals(1, messages.size()); /* analyze the content of the message */ SmtpMessage receivedMessage = messages.get(0); String from = receivedMessage.getFrom(); String subject = receivedMessage.getSubject(); String body = receivedMessage.getBody(); Date sentDate = receivedMessage.getSentDate(); ListString> recipientsTo = receivedMessage.getRecipients(RecipientType.TO); ListSmtpAttachment> attachments = receivedMessage.getAttachments(); >

Here are some usages about specific parts of the API. For more examples, look in the tests.

Basically, it is recommended to always use the SmtpServerBuilder class to instanciate a new SmtpServer instance.

The SmtpServer can be configured either to listen to a specific port or to find dynamically a free port to listen to.

A static port can simply be specified like this:

SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.withPort(1025).start()) < //server is listening on port 1025 >

On the other hand, if no port is defined, the SmtpServer will find a free port to listen to when it is started:

SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.start()) < int port = server.getPort(); //port listen by the server >

When the port is not specified, the SmtpServer will try to open a server socket on the default SMTP port (25). If the latter fails (most probably), it will look up for a free port starting from 1024.

Note that generally ports under 1024 can only be used with root privileges.

The SmtpServer provides some utilities that let you create a new Session for message creation and sending. The latter will be automatically connected to the running server (on localhost):

SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.start()) < Session session = server.createSession(); //use the session to create a MimeMessage >

The received messages can be accessed directly through the SmtpServer :

ListSmtpMessage> receivedMessages = smtpServer.readReceivedMessages();

This method will clear the server’s storage cache, hence another invocation of the same method will yield an empty list until a new message has been received.

WARNING: Do not use this method concurrently SmtpServer.receivedMessageReader() because of race conditions.

A simple API is provided to wait and loop over the received messages:

try(SmtpMessageReader reader = smtpServer.receivedMessageReader()) < SmtpMessage smtpMessage = reader.readMessage(); //blocks until the first message is available while(smtpMessage!=null) < /* . */ //blocks until the next message is available smtpMessage = reader.readMessage(); > >

When the SmtpServer is closed, the reader will yield null .

WARNING: Creating multiple instances of SmtpMessageReader will cause a race condition between them and hence, a message will be received only by one of the readers. For the same reasons, do not use SmtpServer.readReceivedMessages() when using a reader.

The API of SmtpMessage provides an easy access to all the basic fields:

String from = smtpMessage.getFrom(); String subject = smtpMessage.getSubject(); String body = smtpMessage.getBody(); Date sentDate = smtpMessage.getSentDate(); ListString> recipientsTo = smtpMessage.getRecipients(RecipientType.TO); ListSmtpAttachment> attachments = smtpMessage.getAttachments();

It is also possible to retrieve some data directly issued from the underlying SMTP exchanges between the server and the client. Those data might differ (even be missing) from the resulting MimeMessage :

String sourceFrom = smtpMessage.getSourceFrom(); ListString> sourceRecipients = smtpMessage.getSourceRecipients();

Typically, the BCC recipients will be absent from the MimeMessage but will be available through the getSourceRecipients() method.

If more specific data has to be accessed, it is possible to retrieve the raw data with the following methods:

MimeMessage mimeMessage = smtpMessage.getMimeMessage(); String mimeMessageStr = smtpMessage.getRawMimeContent();

Multipart messages might contain many attachments that are accessibles with the getAttachments() method of the SmtpMessage . Here is an insight of the SmtpAttachment API:

String filename = attachment.getFilename(); // myFile.pdf String contentType = attachment.getContentType(); // application/pdf; charset=us-ascii; name=myFile.pdf

The content of an attachment can be read with the following piece of code:

try(InputStream is = attachment.openStream()) < //. >

The API includes a utility class to build SMTP messages from the client side that can easily be sent to smtp4j. The MimeMessageBuilder class provides easy-to-use methods to create a Multipart MIME message:

/* SMTP server is started on port 1025 */ SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.withPort(1025).start()) < /* create and send an SMTP message */ MimeMessageBuilder messageBuilder = new MimeMessageBuilder(server). from("source@smtp4j.local"). //use either multiple arguments to("to1@smtp4j.local", "Igôr "). //or a comma-separated list to("to3@smtp4j.local, My Friend "). //or call the method multiple times cc("cc1@smtp4j.local"). cc("cc2@smtp4j.local"). bcc("bcc@smtp4j.local"). at("31.12.2020 23:59:59"). subject("Hello, world !"). body("Hello\r\nGreetings from smtp4j !\r\n\r\nBye."). attachment(new File("file.pdf")); //build the message and send it to smtp4j messageBuilder.send(); //process the received message //. >

It is also possible to use this builder in a production application by using the dedicated Session constructor:

MimeMessageBuilder messageBuilder = new MimeMessageBuilder(session);

It is possible to listen to SmtpServer events by implementing a SmtpServerListener.

SmtpServerListener myListener = new SmtpServerListener() < public void notifyStart(SmtpServer server) < System.out.println("Server has been started"); > public void notifyClose(SmtpServer server) < System.out.println("Server has been closed"); > public void notifyMessage(SmtpServer server, SmtpMessage message) < System.out.println("Message has been received"); > > mySmtpServer.addListener(myListener);

Advanced message handling

By default, once a SmtpMessage has been received, it will be stored in a default DefaultSmtpMessageHandler instance, which can be directly accessed like this:

SmtpMessageHandler messageHandler = smtpServer.getMessageHandler(); DefaultSmtpMessageHandler defaultMessageHandler = (DefaultSmtpMessageHandler)messageHandler;

It is possible to override this default behavior with your custom handler with the following piece of code:

SmtpMessageHandler myCustomHandler = new CustomSmtpMessageHandler(); SmtpServerBuilder builder = new SmtpServerBuilder(); try(SmtpServer server = builder.withMessageHandler(myCustomHandler).start()) < //. >

For now, it is not possible to communicate securely (SMTPS or SSL/TLS) through this API. If the client tries to initiate a secure channel, the connection will be closed.

This project is completely developed during my spare time.

Since I’m a big fan of cryptocurrencies and especially Cardano (ADA), you can send me some coins at the address below (check it here):

addr1q9sgms4vc038nq7hu4499yeszy0rsq3hjeu2k9wraksle8arg0n953hlsrtdzpfnxxw996l4t6qu5xsx8cmmakjcqhksaqpj66 

Источник