src/main/java/org/apache/james/postage/client/POP3Client.java

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package org.apache.james.postage.client;

import java.io.IOException;
import java.util.Iterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.net.pop3.POP3MessageInfo;
import org.apache.james.postage.PostageException;
import org.apache.james.postage.SamplingException;
import org.apache.james.postage.StartupException;
import org.apache.james.postage.execution.Sampler;
import org.apache.james.postage.result.PostageRunnerResult;
import org.apache.james.postage.user.UserList;

/**
 * acts like a MUA using POP3 protocol.<br/>
 * fetches all mails for one (all) users and initiates adding to results
 */
public class POP3Client implements Sampler {

    private static Log log = LogFactory.getLog(POP3Client.class);

    private String host;
    private int port;
    private UserList internalUsers;
    private PostageRunnerResult results;

    public POP3Client(String host, int port, UserList internalUsers, PostageRunnerResult results) {
        this.host = host;
        this.port = port;
        this.internalUsers = internalUsers;
        this.results = results;
    }

    /**
     * checks, if the configured POP3 services is accessable
     */
    public boolean checkAvailability() throws StartupException {
        try {
            org.apache.commons.net.pop3.POP3Client pop3Client = openConnection(this.internalUsers.getRandomUsername());
            closeSession(pop3Client);
        } catch (PostageException e) {
            throw new StartupException("error checking availability");
        }
        return true;
    }

    private void closeSession(org.apache.commons.net.pop3.POP3Client pop3Client) throws PostageException {
        try {
            pop3Client.sendCommand("QUIT");
            pop3Client.disconnect();
        } catch (IOException e) {
            throw new PostageException("error closing pop3 session", e);
        }
    }

    private org.apache.commons.net.pop3.POP3Client openConnection(String username) throws PostageException {
        org.apache.commons.net.pop3.POP3Client pop3Client = new org.apache.commons.net.pop3.POP3Client();
        try {
            pop3Client.connect(this.host, this.port);
            if (!pop3Client.login(this.internalUsers.getEmailAddress(username), this.internalUsers.getPassword())) {
                log.warn("Login did not work for user: " + username);
            }
        } catch (IOException e) {
            throw new PostageException("POP3 service not available", e);
        }
        return pop3Client;
    }

    /**
     * take one POP3 sample for a random user
     */
    public void doSample() throws SamplingException {
        String username = this.internalUsers.getRandomUsername();

        try {
            findAllMatchingTestMail(username);
        } catch (SamplingException e) {
            log.warn("error sampling mail for user " + username);
            throw e;
        }
    }

    /**
     * used after completing with regular test scenario. tries to collect all mails, which are left 
     * unprocessed by the random access. this is done by iterating over all user accounts, looking for mail
     */
    public void doMatchMailForAllUsers() {
        Iterator<String> usernames = this.internalUsers.getUsernames();
        while (usernames.hasNext()) {
            String username = usernames.next();
            try {
                findAllMatchingTestMail(username);
            } catch (SamplingException e) {
                log.warn("error reading mail for user " + username);
            }
        }
    }

    /**
     * for the specified user, fetches all mail and invokes the matching process
     * @param username
     * @throws SamplingException
     */
    private void findAllMatchingTestMail(String username) throws SamplingException {
        try {
            org.apache.commons.net.pop3.POP3Client pop3Client = openConnection(username);

            // retrieve all messages
            POP3MessageInfo[] entries = null;
            try {
                entries = pop3Client.listMessages();
            } catch (Exception e) {
                String errorMessage = "failed to read pop3 account mail list for " + username;
                this.results.addError(500, errorMessage);
                log.info(errorMessage);
                return;
            }

            for (int i = 0; entries != null && i < entries.length; i++) {
                POP3MessageInfo entry = entries[i];

                try {
                    new POP3MailAnalyzeStrategy("pop3", this.results, pop3Client, entry.number, i).handle();
                } catch (Exception exception) {
                    log.warn("error processing pop3 mail", exception);
                }
            }

            closeSession(pop3Client);
        } catch (PostageException e) {
            throw new SamplingException("sample failed", e);
        }
    }
}