blog-spring-cloud-gateway/gateway/.mvn/wrapper/MavenWrapperDownloader.java

/*
 * Copyright 2007-present the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.
 */

import java.net.*;
import java.io.*;
import java.nio.channels.*;
import java.util.Properties;

public class MavenWrapperDownloader {

	private static final String WRAPPER_VERSION = "0.5.6";
	/**
	 * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
	 */
	private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
			+ WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";

	/**
	 * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
	 * use instead of the default one.
	 */
	private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
			".mvn/wrapper/maven-wrapper.properties";

	/**
	 * Path where the maven-wrapper.jar will be saved to.
	 */
	private static final String MAVEN_WRAPPER_JAR_PATH =
			".mvn/wrapper/maven-wrapper.jar";

	/**
	 * Name of the property which should be used to override the default download url for the wrapper.
	 */
	private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";

	public static void main(String args[]) {
		System.out.println("- Downloader started");
		File baseDirectory = new File(args[0]);
		System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());

		// If the maven-wrapper.properties exists, read it and check if it contains a custom
		// wrapperUrl parameter.
		File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
		String url = DEFAULT_DOWNLOAD_URL;
		if (mavenWrapperPropertyFile.exists()) {
			FileInputStream mavenWrapperPropertyFileInputStream = null;
			try {
				mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
				Properties mavenWrapperProperties = new Properties();
				mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
				url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
			}
			catch (IOException e) {
				System.out
						.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
			}
			finally {
				try {
					if (mavenWrapperPropertyFileInputStream != null) {
						mavenWrapperPropertyFileInputStream.close();
					}
				}
				catch (IOException e) {
					// Ignore ...
				}
			}
		}
		System.out.println("- Downloading from: " + url);

		File outputFile = new File(baseDirectory
				.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
		if (!outputFile.getParentFile().exists()) {
			if (!outputFile.getParentFile().mkdirs()) {
				System.out.println(
						"- ERROR creating output directory '" + outputFile.getParentFile()
								.getAbsolutePath() + "'");
			}
		}
		System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
		try {
			downloadFileFromURL(url, outputFile);
			System.out.println("Done");
			System.exit(0);
		}
		catch (Throwable e) {
			System.out.println("- Error downloading");
			e.printStackTrace();
			System.exit(1);
		}
	}

	private static void downloadFileFromURL(String urlString, File destination) throws Exception {
		if (System.getenv("MVNW_USERNAME") != null && System
				.getenv("MVNW_PASSWORD") != null) {
			String username = System.getenv("MVNW_USERNAME");
			char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
			Authenticator.setDefault(new Authenticator() {
				@Override
				protected PasswordAuthentication getPasswordAuthentication() {
					return new PasswordAuthentication(username, password);
				}
			});
		}
		URL website = new URL(urlString);
		ReadableByteChannel rbc;
		rbc = Channels.newChannel(website.openStream());
		FileOutputStream fos = new FileOutputStream(destination);
		fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
		fos.close();
		rbc.close();
	}

}