src/main/java/org/apache/maven/dist/tools/JsoupRetry.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.dist.tools;

import java.io.IOException;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

/**
 * Reads a url with Jsoup, retrying multiple times in case of IOException.
 */
public class JsoupRetry {
    /** Constant <code>MAX_RETRY=3</code> */
    public static final int MAX_RETRY = 3;

    /** Constant <code>WAIT_RETRY_SECONDS=10</code> */
    public static final int WAIT_RETRY_SECONDS = 10;

    /**
     * JsoupRetry constructor.
     */
    public JsoupRetry() {}

    /**
     * <p>get.</p>
     *
     * @param url a {@link java.lang.String} object
     * @return a {@link org.jsoup.nodes.Document} object
     * @throws java.io.IOException if any.
     */
    public static Document get(String url) throws IOException {
        for (int i = 1; i <= MAX_RETRY; i++) {
            try {
                return Jsoup.connect(url)
                        .userAgent("Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:25.0) Gecko/20100101 Firefox/25.0")
                        .maxBodySize(0)
                        .get();
            } catch (IOException ioe) {
                System.err.println("IOException try " + i + " while reading " + url + ": " + ioe.getClass() + " "
                        + ioe.getMessage());

                if (i == MAX_RETRY) {
                    throw new IOException("IOException while reading " + url, ioe);
                }
            }

            try {
                Thread.sleep(WAIT_RETRY_SECONDS * 1000);
            } catch (InterruptedException e) {
                // not expected to happen
            }
        }

        return null;
    }
}