Android™

Get a Header Field from an Alternative Body

Demonstrates the Chilkat Email.GetAltHeaderField method, which returns the value of a header field within the Nth alternative body's MIME sub-part. The first argument is the zero-based alternative index; the second is the header field name. This example builds a message with plain-text and HTML alternatives and reads the Content-Type of the first alternative.

Background: A multipart/alternative message is a tree: each alternative body is its own MIME sub-part with its own little header block (Content-Type, Content-Transfer-Encoding, etc.). The top-level Email header methods read the message headers, whereas GetAltHeaderField reaches into a specific alternative's sub-part — useful for inspecting exactly how each representation is typed and encoded.

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// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //  Demonstrates the GetAltHeaderField method, which returns the value of a header field
    //  within the Nth alternative body's MIME sub-part.  The 1st argument is the zero-based
    //  alternative index; the 2nd is the header field name.

    CkEmail email = new CkEmail();

    //  Create an email with plain-text and HTML alternatives.
    email.SetTextBody("This is the plain-text alternative.","text/plain");
    email.AddHtmlAlternativeBody("<html><body>This is the HTML alternative.</body></html>");

    //  Get the Content-Type header of the first alternative body (index 0).
    String ct = email.getAltHeaderField(0,"Content-Type");
    Log.i(TAG, "Alternative 0 Content-Type: " + ct);

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}