org.jboss.forge.website.service.Downloader.java Source code

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Here is the source code for org.jboss.forge.website.service.Downloader.java

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/*
 * Copyright 2014 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Eclipse Public License version 1.0, available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.jboss.forge.website.service;

import java.io.Serializable;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Logger;
import java.util.regex.Pattern;

import javax.inject.Singleton;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.ocpsoft.common.util.Streams;
import org.ocpsoft.urlbuilder.util.Decoder;

/**
 * @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
 */
@Singleton
public class Downloader implements Serializable {
    private static final Logger log = Logger.getLogger(Downloader.class.getName());
    private static final long serialVersionUID = 1111860061208554914L;
    private static final long CACHE_EXPIRY_INTERVAL = 1000 * 60 * 60;

    // TODO Cache this on disk or dcp.jboss.org instead of in memory.
    private final Map<String, CacheEntry> cache = new ConcurrentHashMap<>();

    public String download(String url) throws IllegalStateException {
        String content = getContentFromCache(url);

        if (content == null) {

            try (CloseableHttpClient client = HttpClientBuilder.create().build()) {
                HttpGet get = new HttpGet(url);
                HttpResponse response = client.execute(get);

                if (response.getStatusLine().getStatusCode() == 200)
                    content = Streams.toString(response.getEntity().getContent());

                if (response.getStatusLine().getStatusCode() / 10 == 20)
                    cache.put(url, new CacheEntry(url, content, System.currentTimeMillis()));

                else
                    throw new IllegalStateException("failed! (server returned status code: "
                            + response.getStatusLine().getStatusCode() + ")");
            } catch (IllegalStateException e) {
                throw e;
            } catch (Exception e) {
                throw new IllegalStateException("Failed to download: " + url, e);
            }

        }

        if (content == null) {
            content = getContentFromCacheUnrestricted(url);
        }

        return content;
    }

    public void invalidateCaches() {
        for (CacheEntry entry : cache.values()) {
            entry.invalidate();
        }
    }

    public void invalidateCachesByAddress(String pattern) {
        pattern = ".*" + Pattern.quote(pattern) + ".*";
        log.info("Invalidating caches for pattern [" + pattern + "]");
        for (CacheEntry entry : cache.values()) {
            if (entry.getAddress().matches(pattern) || Decoder.query(entry.getAddress()).matches(pattern)
                    || Decoder.path(entry.getAddress()).matches(pattern)) {
                log.info("Invalidating cache entry [" + entry.getAddress() + "] for pattern [" + pattern + "]");
                entry.invalidate();
            }
        }
    }

    private String getContentFromCache(String url) {
        String result = null;
        CacheEntry entry = cache.get(url);
        if (entry != null && System.currentTimeMillis() - entry.getTime() < CACHE_EXPIRY_INTERVAL)
            result = entry.getContent();
        return result;
    }

    private String getContentFromCacheUnrestricted(String url) {
        String result = null;
        CacheEntry entry = cache.get(url);
        if (entry != null)
            result = entry.getContent();
        return result;
    }
}