Java

Convert 8-bit MIME Parts to Base64

Demonstrates the Chilkat Mime.Convert8Bit method, which recursively converts every part whose Content-Transfer-Encoding is 8bit or binary to base64. It takes no arguments and is a void method.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The original SMTP standard only guaranteed 7-bit transport, and some legacy servers still reject or mangle raw 8-bit and binary content. Converting those parts to base64 — a 7-bit-safe encoding — makes the whole message safe to relay through such systems without loss. It walks the entire tree, so a multipart message with several offending parts is fixed in one call.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    CkMime mime = new CkMime();
    success = mime.LoadMimeFile("qa_data/message.eml");
    if (success == false) {
        System.out.println(mime.lastErrorText());
        return;
        }

    //  Recursively convert every part whose Content-Transfer-Encoding is 8bit or binary to base64.
    //  This makes the MIME safe to transmit over channels that only support 7-bit text (such as some
    //  legacy SMTP servers).
    mime.Convert8Bit();

    System.out.println("8bit/binary parts converted to base64.");
    String mimeText = mime.getMime();
    if (mime.get_LastMethodSuccess() == false) {
        System.out.println(mime.lastErrorText());
        return;
        }

    System.out.println(mimeText);
  }
}