com.payu.ratel.context.ProcessContext Maven / Gradle / Ivy

Go to download
package com.payu.ratel.context;

import java.util.UUID;

/**
 * A context of a process that is always available via
 * {@link ProcessContext#getInstance()}.
 * It is automatically transported over ratel remote service calls.
 */
public class ProcessContext implements Cloneable {

    private static final ThreadLocal INSTANCE = new ThreadLocal() {

        protected ProcessContext initialValue() {
            return new ProcessContext();
        }
    };

    private String processIdentifier;

    public static ProcessContext getInstance() {
        return INSTANCE.get();
    }

    /**
     * Get unique identifier of this process.
     *
     * @return the identifier, typically 36 char UUID,
     *         or null, if it is not set.
     */
    public String getProcessIdentifier() {
        return processIdentifier;
    }

    public void setProcessIdentifier(String processId) {
        this.processIdentifier = processId;
    }

    /**
     * Generate new random process identifier, given that it is not presently
     * set.
     *
     * @throws IllegalStateException
     *             when currently set process id is not null.
     */
    public void generateProcessIdentifier() {
        if (getProcessIdentifier() != null) {
            throw new IllegalStateException("Cannot generate new process identifier when present is not cleared");
        }
        setProcessIdentifier(UUID.randomUUID().toString());
    }

    public void clearProcessIdentifier() {
        setProcessIdentifier(null);
    }

    @Override
    @SuppressWarnings("PMD")
    protected ProcessContext clone() {
        try {
            return (ProcessContext) super.clone();
        } catch (CloneNotSupportedException e) {
            // won't happen
            throw new IllegalStateException(e);
        }
    }

    @Override
    public String toString() {
        return "ProcessContext [processIdentifier=" + processIdentifier + "]";
    }

}