Creating your own Crontab plugin

You can create your own Crontab plugin.

Conditions:

The new Crontab plugin class must implement the “CronAdapter” interface.
The new Crontab plugin class must be declared under the package “com.openkm.plugin.cron”.
The new Crontab plugin class must be annotated with “@PluginImplementation”.
The new Crontab plugin class must extend “BaseCronPlugin”.

CronAdapter interface:

package com.openkm.plugin.cron;

import net.xeoh.plugins.base.Plugin;

public interface CronAdapter extends Runnable, Plugin {
  /**
   * The cron name
   */
  String getName();

  /**
   * The default cron expression what will be registered the first time
   */
  String getCronExpression();

  /**
   * Return if task is running or not
   */
  boolean isRunning();

  /**
   * Cron task execution
   */
  void execute() throws Throwable;
}

The new class must be loaded into the package com.openkm.plugin.cron because the application plugin system will try to load it from there.

Method description

Method	Type	Description
getName()	String	Returns the name of the crontab.
getCronExpression	String	Returns the cron expression.
isRunning	Boolean	Returns true when the cron task is running.
execute	Void	Executes the cron task.

Example of the disposition cron implementation

package com.openkm.plugin.cron;

import com.openkm.api.OKMRepository;
import com.openkm.bean.Folder;
import com.openkm.module.db.stuff.DbSessionManager;
import com.openkm.util.FileLogger;
import net.xeoh.plugins.base.annotations.PluginImplementation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;


@PluginImplementation
public class TestCron extends BaseCronPlugin implements CronAdapter {
    private static Logger log = LoggerFactory.getLogger(TestCron.class);
    private static String LOG_NAME = "TestCron";

    @Autowired
    private OKMRepository okmRepository;

    @Override
    public String getName() {
        return "Cron test";
    }

    @Override
    public String getCronExpression() {
        return "0 * * * * *";
    }

    @Override
    public void execute() {
        try {
            FileLogger.info(LOG_NAME, ">>> Started");
            // Use always system token in your cron
            String token = DbSessionManager.getInstance().getSystemToken();
            Folder rootFolder = okmRepository.getRootFolder(token);
            FileLogger.info(LOG_NAME, "Root folder uuid: " + rootFolder.getUuid());
            FileLogger.info(LOG_NAME, ">>> Finished");
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    }
}

Understanding the crontab job execution context

Execution context:

Crontab job is executed by internal users named “system” ( the job does not have a valid user session ).
Crontab job is executed by the administrator user ( the job has a valid user session ).

It is good practice to use the system token when calling API methods in a crontab task:

String systemToken = DbSessionManager.getInstance().getSystemToken();
OKMFolder.getInstance().createSimple(systemToken, "/okm:root/test")