Added a hook to delete all temporary files; fixes gh-151

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/git/ProjectGitHandler.java

@@ -17,7 +17,6 @@
 package org.springframework.cloud.release.internal.git;
 
 import java.io.File;
-import java.nio.file.Files;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -30,6 +29,7 @@ import org.springframework.cloud.release.internal.ReleaserProperties;
 import org.springframework.cloud.release.internal.ReleaserPropertiesAware;
 import org.springframework.cloud.release.internal.pom.ProjectVersion;
 import org.springframework.cloud.release.internal.pom.Projects;
+import org.springframework.cloud.release.internal.tech.TemporaryFileStorage;
 import org.springframework.util.StringUtils;
 
 /**
@@ -61,6 +61,11 @@ public class ProjectGitHandler implements ReleaserPropertiesAware {
 		this.properties = properties;
 		this.githubMilestones = new GithubMilestones(properties);
 		this.githubIssues = new GithubIssues(properties);
+		registerShutdownHook();
+	}
+
+	private void registerShutdownHook() {
+		Runtime.getRuntime().addShutdownHook(new Thread(TemporaryFileStorage::cleanup));
 	}
 
 	public void commitAndTagIfApplicable(File project, ProjectVersion version) {
@@ -213,7 +218,7 @@ public class ProjectGitHandler implements ReleaserPropertiesAware {
 			File destinationDir = this.properties.getGit()
 					.getCloneDestinationDir() != null
 							? new File(this.properties.getGit().getCloneDestinationDir())
-							: Files.createTempDirectory("releaser").toFile();
+							: TemporaryFileStorage.createTempDir("releaser");
 			File clonedLocation = gitRepo(destinationDir).cloneProject(urIish);
 			CACHE.put(urIish, clonedLocation);
 			return clonedLocation;

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/tech/TemporaryFileStorage.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2013-2019 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.
+ */
+
+package org.springframework.cloud.release.internal.tech;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Queue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Stores all generated temporary folders.
+ *
+ * @author Marcin Grzejszczak
+ */
+public final class TemporaryFileStorage {
+
+	private static final Log log = LogFactory.getLog(TemporaryFileStorage.class);
+
+	private static final int TEMP_DIR_ATTEMPTS = 10000;
+
+	/**
+	 * There are problems with removal of temporary files. That's why we're creating a
+	 * bounded in-memory storage of unpacked files and later we register a shutdown hook
+	 * to remove all these files.
+	 */
+	private static final Queue<File> TEMP_FILES_LOG = new LinkedBlockingQueue<>(1000);
+
+	private TemporaryFileStorage() {
+		throw new IllegalStateException("Can't instantiate a utility class");
+	}
+
+	private static void add(File file) {
+		TEMP_FILES_LOG.add(file);
+	}
+
+	private static Queue<File> files() {
+		return TEMP_FILES_LOG;
+	}
+
+	public static void cleanup() {
+		try {
+			for (File file : TemporaryFileStorage.files()) {
+				if (file.isDirectory()) {
+					Files.walkFileTree(file.toPath(), new SimpleFileVisitor<Path>() {
+						@Override
+						public FileVisitResult visitFile(Path file,
+								BasicFileAttributes attrs) throws IOException {
+							if (log.isTraceEnabled()) {
+								log.trace("Removing file [" + file + "]");
+							}
+							Files.delete(file);
+							return FileVisitResult.CONTINUE;
+						}
+
+						@Override
+						public FileVisitResult postVisitDirectory(Path dir,
+								IOException exc) throws IOException {
+							if (log.isTraceEnabled()) {
+								log.trace("Removing dir [" + dir + "]");
+							}
+							Files.delete(dir);
+							return FileVisitResult.CONTINUE;
+						}
+					});
+				}
+				else {
+					Files.delete(file.toPath());
+				}
+			}
+		}
+		catch (NoClassDefFoundError | IOException e) {
+			// Added NoClassDefFoundError cause sometimes it's visible in the builds
+			// this error is completely harmless
+			if (log.isTraceEnabled()) {
+				log.trace("Failed to remove temporary file", e);
+			}
+		}
+	}
+
+	// taken from Guava
+	public static File createTempDir(String tempDirPrefix) {
+		File baseDir = new File(System.getProperty("java.io.tmpdir"));
+		String baseName = tempDirPrefix + "-" + System.currentTimeMillis() + "-";
+		for (int counter = 0; counter < TEMP_DIR_ATTEMPTS; counter++) {
+			File tempDir = new File(baseDir, baseName + counter);
+			if (tempDir.mkdir()) {
+				add(tempDir);
+				return tempDir;
+			}
+		}
+		throw new IllegalStateException("Failed to create directory within "
+				+ TEMP_DIR_ATTEMPTS + " attempts (tried " + baseName + "0 to " + baseName
+				+ (TEMP_DIR_ATTEMPTS - 1) + ")");
+	}
+
+}