POP3 supports simple download-and-delete requirements for access to remote mailboxes.
Java Mail comes with Provider implementations for POP3 and IMAP, and the secure versions of those as POP3S and IMAPS.
This Howto connects to a server using the POP3S (Secure, encrypted POP3) to download messages with or without attachments and save them into files.
import java.io.*; import java.util.*; import javax.mail.*; import javax.mail.internet.MimeBodyPart; public class ReceiveMailPOP3 { private static final String HOST = "pop.gmail.com"; private static final String USERNAME = "myemail@gmail.com"; private static final String PASSWORD = "******"; public static void doit() throws MessagingException, IOException { Folder folder = null; Store store = null; try { Properties props = new Properties(); props.put("mail.store.protocol", "pop3s"); // Google uses POP3S not POP3 Session session = Session.getDefaultInstance(props); // session.setDebug(true); store = session.getStore(); store.connect(HOST, USERNAME, PASSWORD); folder = store.getDefaultFolder().getFolder("INBOX"); folder.open(Folder.READ_ONLY); Message[] messages = folder.getMessages(); System.out.println("No of Messages : " + folder.getMessageCount()); System.out.println("No of Unread Messages : " + folder.getUnreadMessageCount()); for (int i=0; i < messages.length; ++i) { System.out.println("MESSAGE #" + (i + 1) + ":"); Message msg = messages[i]; String from = "unknown"; if (msg.getReplyTo().length >= 1) { from = msg.getReplyTo()[0].toString(); } else if (msg.getFrom().length >= 1) { from = msg.getFrom()[0].toString(); } String subject = msg.getSubject(); System.out.println("Saving ... " + subject +" " + from); // you may want to replace the spaces with "_" // the files will be saved into the TEMP directory String filename = "c:/temp/" + subject; saveParts(msg.getContent(), filename); } } finally { if (folder != null) { folder.close(true); } if (store != null) { store.close(); } } } public static void saveParts(Object content, String filename) throws IOException, MessagingException { OutputStream out = null; InputStream in = null; try { if (content instanceof Multipart) { Multipart multi = ((Multipart)content); int parts = multi.getCount(); for (int j=0; j < parts; ++j) { MimeBodyPart part = (MimeBodyPart)multi.getBodyPart(j); if (part.getContent() instanceof Multipart) { // part-within-a-part, do some recursion... saveParts(part.getContent(), filename); } else { String extension = ""; if (part.isMimeType("text/html")) { extension = "html"; } else { if (part.isMimeType("text/plain")) { extension = "txt"; } else { // Try to get the name of the attachment extension = part.getDataHandler().getName(); } filename = filename + "." + extension; System.out.println("... " + filename); out = new FileOutputStream(new File(filename)); in = part.getInputStream(); int k; while ((k = in.read()) != -1) { out.write(k); } } } } } } finally { if (in != null) { in.close(); } if (out != null) { out.flush(); out.close(); } } } public static void main(String args[]) throws Exception { ReceiveMailPOP3.doit(); } }
Done! Happy Coding!
Related posts:
Setting Up Swagger 2 with a Spring REST API
Java toString() Method
The Basics of Java Security
Spring Boot - Twilio
Guide to Java 8 groupingBy Collector
Introduction to Eclipse Collections
How to Manually Authenticate User with Spring Security
Allow user:password in URL
Java Program to Implement ConcurrentHashMap API
Java Program to Implement EnumMap API
Java Program to Implement Max Heap
Java Program to Implement Strassen Algorithm
Java Program to Represent Graph Using Adjacency List
Java Program to Implement Affine Cipher
Guide to Spring Cloud Kubernetes
Java Program to Implement Sorted Doubly Linked List
Netflix Archaius with Various Database Configurations
Java Perform to a 2D FFT Inplace Given a Complex 2D Array
Java Program to Implement Segment Tree
Java 8 Collectors toMap
Java Program to Test Using DFS Whether a Directed Graph is Weakly Connected or Not
Java Program to Find the Minimum value of Binary Search Tree
Java Program to Implement Dijkstra’s Algorithm using Queue
Java Program to Check Whether it is Weakly Connected or Strongly Connected for a Directed Graph
Sorting in Java
Java Program to Implement Knapsack Algorithm
Guide to Dynamic Tests in Junit 5
Ép kiểu trong Java (Type casting)
Command-Line Arguments in Java
Comparing Objects in Java
Hướng dẫn Java Design Pattern – Abstract Factory
How to Iterate Over a Stream With Indices