public void setAction(String action) {
        this.action = action;
    }
<p>
The action to occur if the recipient taps the push notification. Valid values are:
</p>
<ul>
<li>
<p>
OPEN_APP - Your app opens or it becomes the foreground app if it was sent to the background. This is the default
action.
</p>
</li>
<li>
<p>
DEEP_LINK - Your app opens and displays a designated user interface in the app. This action uses the deep-linking
features of the Android platform.
</p>
</li>
<li>
<p>
URL - The default mobile browser on the recipient's device opens and loads the web page at a URL that you
specify.
</p>
</li>
</ul>

@param action
       The action to occur if the recipient taps the push notification. Valid values are:</p>
       <ul>
       <li>
       <p>
       OPEN_APP - Your app opens or it becomes the foreground app if it was sent to the background. This is the
       default action.
       </p>
       </li>
       <li>
       <p>
       DEEP_LINK - Your app opens and displays a designated user interface in the app. This action uses the
       deep-linking features of the Android platform.
       </p>
       </li>
       <li>
       <p>
       URL - The default mobile browser on the recipient's device opens and loads the web page at a URL that you
       specify.
       </p>
       </li>
@see Action
aws-java-sdk-pinpoint/src/main/java/com/amazonaws/services/pinpoint/model/GCMMessage.java