org.apache.axis2.deployment.util.TempFileManager Maven / Gradle / Ivy
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* 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.axis2.deployment.util;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.PrintStream;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Generates and properly cleans up temporary files. Similar to {@link
* File#createTempFile(java.lang.String, java.lang.String)}, this class provides a static method to
* create temporary files. The temporary files will be created in a special directory to be cleaned
* up the next time this class is loaded by the JVM. This functionality is required because Win32
* platforms will not allow the JVM to delete files that are open. This causes problems with items
* such as JARs that get opened by a URLClassLoader and can therefore not be deleted by the JVM
* (including deleteOnExit).
*
* The caller should not need to create an instance of this class, although it is possible. Simply
* use the static methods to perform the required operations. Note that all files created by this
* class should be considered as deleted at JVM exit (although the actual deletion may be delayed).
* If persistent temporary files are required, use {@link java.io.File} instead.
*
* Refer to Sun bugs 4171239 and 4950148 for more details.
*
* Thanks to Mike Pilone for this code, which was sourced from
* http://www.devx.com/Java/Article/22018/ and contributed to Apache.
*/
public class TempFileManager {
/**
* Creates a temporary file in the proper directory to allow for cleanup after execution. This
* method delegates to {@link File#createTempFile(java.lang.String, java.lang.String,
* java.io.File)} so refer to it for more documentation. Any file created using this method should
* be considered as deleted at JVM exit; therefore, do not use this method to create files that
* need to be persistent between application runs.
*
* @param prefix the prefix string used in generating the file name; must be at least three
* characters long
* @param suffix the suffix string to be used in generating the file's name; may be null, in which
* case the suffix ".tmp" will be used
* @return an abstract pathname denoting a newly created empty file
* @throws IOException if a file could not be created
*/
@SuppressWarnings({"ResultOfMethodCallIgnored"})
public static File createTempFile(String prefix, String suffix)
throws IOException {
// Check to see if you have already initialized a temp directory
// for this class.
if (sTmpDir == null) {
// Initialize your temp directory. You use the java temp directory
// property, so you are sure to find the files on the next run.
String tmpDirName = System.getProperty("java.io.tmpdir");
File tmpDir = File.createTempFile(TEMP_DIR_PREFIX, ".tmp",
new File(tmpDirName));
// Delete the file if one was automatically created by the JVM.
// You are going to use the name of the file as a directory name,
// so you do not want the file laying around.
tmpDir.delete();
// Create a lock before creating the directory so
// there is no race condition with another application trying
// to clean your temp dir.
File lockFile = new File(tmpDirName, tmpDir.getName() + ".lck");
lockFile.createNewFile();
// Set the lock file to delete on exit so it is properly cleaned
// by the JVM. This will allow the TempFileManager to clean
// the overall temp directory next time.
lockFile.deleteOnExit();
// Make a temp directory that you will use for all future requests.
if (!tmpDir.mkdirs()) {
throw new IOException("Unable to create temporary directory:"
+ tmpDir.getAbsolutePath());
}
sTmpDir = tmpDir;
}
// Generate a temp file for the user in your temp directory
// and return it.
return File.createTempFile(prefix, suffix, sTmpDir);
}
/**
* Utility method to load the TempFileManager at any time and allow it to clean the temporary
* files that may be left from previous instances
*
* @param args command line arguments are currently not supported
*/
public static void main(String[] args) {
// Although the JVM will load the class in order to
// run the main method, this gives a little clarity to
// what is happening and why we want the main method.
try {
// This will load the TempFileManager, which will
// cause the static block to execute, cleaning
// any old temp files.
Class.forName(TempFileManager.class.getName());
}
catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
}
/**
* Deletes all of the files in the given directory, recursing into any sub directories found. Also
* deletes the root directory.
*
* @param rootDir the root directory to be recursively deleted
* @throws IOException if any file or directory could not be deleted
*/
private static void recursiveDelete(File rootDir)
throws IOException {
// Select all the files
File[] files = rootDir.listFiles();
if (files != null) {
for (File file : files) {
// If the file is a directory, we will
// recursively call delete on it.
if (file.isDirectory()) {
recursiveDelete(file);
} else {
// It is just a file so we are safe to
// delete it
if (!file.delete()) {
throw new IOException("Could not delete: " + file.getAbsolutePath());
}
}
}
}
// Finally, delete the root directory now
// that all of the files in the directory have
// been properly deleted.
if (!rootDir.delete()) {
throw new IOException("Could not delete: " + rootDir.getAbsolutePath());
}
}
/** The prefix for the temp directory in the system temp directory */
private final static String TEMP_DIR_PREFIX = "axis2-tmp-";
/** The temp directory to generate all files in */
private static File sTmpDir = null;
/**
* Static block used to clean up any old temp directories found -- the JVM
* will run this block when a class loader loads the class.
*/
static {
// Clean up any old temp directories by listing
// all of the files, using a filter that will
// return only directories that start with your
// prefix.
FileFilter tmpDirFilter =
new FileFilter() {
public boolean accept(File pathname) {
return (pathname.isDirectory() &&
pathname.getName().startsWith(TEMP_DIR_PREFIX));
}
};
// Get the system temp directory and filter the files.
String tmpDirName = System.getProperty("java.io.tmpdir");
File tmpDir = new File(tmpDirName);
File[] tmpFiles = tmpDir.listFiles(tmpDirFilter);
// Find all the files that do not have a lock by
// checking if the lock file exists.
if (tmpFiles != null) {
for (File tmpFile : tmpFiles) {
// Create a file to represent the lock and test.
File lockFile = new File(tmpFile.getParent(), tmpFile.getName() + ".lck");
if (!lockFile.exists()) {
// Delete the contents of the directory since
// it is no longer locked.
Logger.getLogger("default").log(Level.FINE,
"TempFileManager::deleting old temp directory " +
tmpFile);
try {
recursiveDelete(tmpFile);
}
catch (IOException ex) {
// You log at a fine level since not being able to delete
// the temp directory should not stop the application
// from performing correctly. However, if the application
// generates a lot of temp files, this could become
// a disk space problem and the level should be raised.
Logger.getLogger("default").log(Level.INFO,
"TempFileManager::unable to delete " +
tmpFile.getAbsolutePath());
// Print the exception.
ByteArrayOutputStream ostream = new ByteArrayOutputStream();
ex.printStackTrace(new PrintStream(ostream));
Logger.getLogger("default").log(Level.FINE, ostream.toString());
}
}
}
}
}
}
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