Groovy Scripts

import com.atlassian.confluence.api.service.content.ContentPropertyService
import com.atlassian.sal.api.component.ComponentLocator
import com.atlassian.confluence.api.model.content.Content;
import com.atlassian.confluence.api.model.content.JsonContentProperty;
import com.atlassian.confluence.api.model.content.id.ContentId;
import com.atlassian.confluence.api.service.content.ContentPropertyService;
import com.atlassian.confluence.api.service.content.ContentService;
import com.atlassian.confluence.json.json.JsonString;
import com.atlassian.confluence.api.model.Expansion;
import groovy.json.JsonSlurper
ContentPropertyService contentPropertyService = ComponentLocator.getComponent(ContentPropertyService);
try {
    // Create a Finder
    ContentPropertyService.ContentPropertyFinder finder = contentPropertyService.find(new Expansion("metadata"));
    // Find the Pages Classification Property
    JsonContentProperty property = finder
        .withContentId(ContentId.of(65611L)) // The Page ID
        .withPropertyKey("classification") // The fixed Content Property Name
        .fetchOrNull(); // If there isn't one, return null.
    if(property != null) {
        // We have a valid property
        String propertyAsString = property.getValue().getValue();
        
        // Convert to an object
        JsonSlurper slurper = new JsonSlurper();
        def propertyAsJson = slurper.parseText(propertyAsString);
        def index = propertyAsJson["name"]["index"];
        
        // We can do something useful with the level index here.
        // 0 is the first level, 1 is the second level and so on...
        if(index == 0) {
            return "Level is Highly Restricted (according to the default levels)";
        } else if(index == 1) {
            return "Level is Restricted (according to the default levels)";
        } else if(index == 2) {
            return "Level is Internal (according to the default levels)";
        } else if(index == 3) {
            return "Level is Public (according to the default levels)";
        }
    } else {
        // Page is not classified yet
        return;
    }
} catch(Exception e) {
    // The script failed for some reason
    return e.getMessage();
}