server/protocols/webadmin/webadmin-mailqueue/src/main/java/org/apache/james/webadmin/service/ClearMailQueueTask.java

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 * to you under the Apache License, Version 2.0 (the            *
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package org.apache.james.webadmin.service;

import java.time.Clock;
import java.time.Instant;
import java.util.Optional;

import org.apache.james.queue.api.MailQueue;
import org.apache.james.queue.api.ManageableMailQueue;
import org.apache.james.task.Task;
import org.apache.james.task.TaskExecutionDetails;
import org.apache.james.task.TaskType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ClearMailQueueTask implements Task {

    public static class AdditionalInformation implements TaskExecutionDetails.AdditionalInformation {
        private final String mailQueueName;
        private final long initialCount;
        private final long remainingCount;
        private final Instant timestamp;

        public AdditionalInformation(String mailQueueName, long initialCount, long remainingCount, Instant timestamp) {
            this.mailQueueName = mailQueueName;
            this.initialCount = initialCount;
            this.remainingCount = remainingCount;
            this.timestamp = timestamp;
        }

        public String getMailQueueName() {
            return mailQueueName;
        }

        public long getInitialCount() {
            return initialCount;
        }

        public long getRemainingCount() {
            return remainingCount;
        }

        @Override
        public Instant timestamp() {
            return timestamp;
        }
    }

    public static class UnknownSerializedQueue extends RuntimeException {
        public UnknownSerializedQueue(String queueName) {
            super("Unable to retrieve '" + queueName + "' queue");
        }
    }

    private static final Logger LOGGER = LoggerFactory.getLogger(ClearMailQueueTask.class);
    public static final TaskType TYPE = TaskType.of("clear-mail-queue");

    private final ManageableMailQueue queue;
    private final long initialCount;

    public ClearMailQueueTask(ManageableMailQueue queue) {
        this.queue = queue;
        initialCount = getRemainingSize();
    }

    @Override
    public Result run() {
        try {
            queue.clear();
        } catch (MailQueue.MailQueueException e) {
            LOGGER.error("Clear MailQueue got an exception", e);
            return Result.PARTIAL;
        }

        return Result.COMPLETED;
    }

    @Override
    public TaskType type() {
        return TYPE;
    }

    @Override
    public Optional<TaskExecutionDetails.AdditionalInformation> details() {
        return Optional.of(new AdditionalInformation(queue.getName(), initialCount, getRemainingSize(), Clock.systemUTC().instant()));
    }

    ManageableMailQueue getQueue() {
        return queue;
    }

    private long getRemainingSize() {
        try {
            return queue.getSize();
        } catch (MailQueue.MailQueueException e) {
            throw new RuntimeException(e);
        }
    }
}