Java

Get a MIME Header Field Value

Demonstrates the Chilkat Mime.GetHeaderField method, which returns the value of the first header field whose name matches case-insensitively. The only argument is the field name; it returns null when no matching field exists.

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

Background: This is the everyday way to read a header value — the Subject, a Message-ID, a custom X- header. Because a missing field returns null, the returned value is assigned to a variable and checked rather than used directly, so an absent header is handled cleanly instead of surfacing as an error later. Only the first matching occurrence is returned; iterate by index to see duplicates.

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Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Mime;

public class ChilkatExample {

    public static void main(String[] args) {
        Mime mime = new Mime();
        try {
            mime.loadMimeFile("qa_data/message.eml");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Return the value of the first header field with a matching (case-insensitive) name.
        // GetHeaderField returns null when no matching field exists, so assign it to a string variable
        // and check for success.
        String subject = mime.getHeaderField("Subject");
        if (subject == null) {
            System.out.println(mime.getLastErrorText());
            return;
        }

        System.out.println("Subject: " + subject);
    }
}