JndiInputDir.java

/**
 * Copyright (c) 2013-2016, The SeedStack authors <http://seedstack.org>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
package org.seedstack.seed.web.internal.scan.tomcat;

import com.google.common.base.Joiner;
import com.google.common.collect.AbstractIterator;
import org.reflections.vfs.Vfs;
import org.seedstack.seed.SeedException;
import org.seedstack.seed.web.internal.WebErrorCode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import java.net.URL;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Deque;
import java.util.List;

/**
 * VFS directory implementation for JNDI directory scanning.
 */
class JndiInputDir implements Vfs.Dir {
    private static final Logger LOGGER = LoggerFactory.getLogger(JndiInputDir.class);

    private final URL url;
    private final List<String> fullPath = new ArrayList<>();
    private final Deque<DirContext> dirContextDeque = new ArrayDeque<>();
    private final Deque<NamingEnumeration<NameClassPair>> enumerationDeque = new ArrayDeque<>();

    JndiInputDir(URL url) {
        this.url = url;
    }

    @Override
    public Iterable<Vfs.File> getFiles() {
        return () -> new AbstractIterator<Vfs.File>() {
            {
                try {
                    Object content = url.openConnection().getContent();
                    dirContextDeque.push((DirContext) content);
                    enumerationDeque.push(((DirContext) content).list("/"));
                    fullPath.add(null);
                } catch (Exception e) {
                    LOGGER.warn("Unable to open JNDI directory at {}, ignoring it", url.toExternalForm(), e);
                }
            }

            @Override
            protected Vfs.File computeNext() {
                try {
                    JndiInputFile nextFile = findNextFile();

                    if (nextFile == null) {
                        return endOfData();
                    } else {
                        return nextFile;
                    }
                } catch (NamingException e) {
                    throw SeedException.wrap(e, WebErrorCode.UNABLE_TO_SCAN_TOMCAT_JNDI_DIRECTORY).put("url", url.toExternalForm());
                }
            }
        };
    }

    @Override
    public void close() {
        for (DirContext dirContext : dirContextDeque) {
            try {
                dirContext.close();
            } catch (NamingException e) {
                LOGGER.warn("Unable to close JNDI directory at {}", url.toExternalForm(), e);
            }
        }

        enumerationDeque.clear();
        dirContextDeque.clear();
        fullPath.clear();
    }

    @Override
    public String getPath() {
        return url.getPath();
    }

    private JndiInputFile findNextFile() throws NamingException {
        while (!enumerationDeque.isEmpty() && enumerationDeque.peek().hasMore()) {
            NameClassPair next = enumerationDeque.peek().next();
            Object entry = dirContextDeque.peek().lookup(next.getName());
            if (entry instanceof DirContext) {
                dirContextDeque.push((DirContext) entry);
                enumerationDeque.push(((DirContext) entry).list("/"));
                fullPath.add(next.getName());
            } else {
                return new JndiInputFile(entry, String.format("%s/%s", Joiner.on("/").skipNulls().join(fullPath), next.getName()));
            }
        }

        if (!enumerationDeque.isEmpty()) {
            enumerationDeque.pop();
            dirContextDeque.pop();
            fullPath.remove(fullPath.size() - 1);

            return findNextFile();
        } else {
            return null;
        }
    }
}