package com.btaz.datautil.files;
import com.btaz.datautil.DataUtilException;
import com.btaz.datautil.files.comparator.FilePathComparator;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.*;
/**
* This class is used to add files for deletion. This is useful when you create file structures that you later want to
* delete all at once. You first add the files and directories you want to add. Once the delete all method is called
* all the tracked files will be deleted in reverse order, bottom to top. Note that this class assumes that the delete
* all method will be called. There's not automatic call on a JVM termination. Note that if you put untracked files and
* directories inside a tracked directory structure, then the deleteAll method will fail.
*/
public class FileTracker {
private Set<File> trackedFiles;
private FilePathComparator filePathComparator;
/**
* Default constructor
*/
public FileTracker() {
trackedFiles = new HashSet<File>();
filePathComparator = new FilePathComparator();
}
/**
* Track a new file
* @param file tracked file
*/
public void add(File file) {
if(file != null) {
trackedFiles.add(file);
}
}
/**
* Track a new list of new files and directories
* @param files list of files and directories
*/
public void add(List<File> files) {
if(files != null) {
trackedFiles.addAll(files);
}
}
/**
* Track a new array of new files and directories
* @param files array of files and directories
*/
public void add(File[] files) {
if(files != null) {
Collections.addAll(trackedFiles, files);
}
}
/**
* Create and add a new file
* @param dir file directory
* @param filename filename
* @return file new file
* @throws DataUtilException data util exception
*/
public File createFile(File dir, String filename) throws DataUtilException {
if(dir == null) {
throw new DataUtilException("The directory parameter can't be a null value");
}
try {
File file = new File(dir, filename);
return createFile(file);
} catch (Exception e) {
throw new DataUtilException("Invalid file: " + filename);
}
}
/**
* Create and add a new file
* @param file new file
* @return file new file
*/
public File createFile(File file) throws DataUtilException {
if(file == null) {
throw new DataUtilException("File parameter can not be a null value");
}
try {
if(! file.createNewFile()) {
throw new DataUtilException("Failed to create file. Result of File.createNewFile() was false.");
}
trackedFiles.add(file);
} catch (IOException e) {
throw new DataUtilException("Failed to create file: " + file.getAbsolutePath(), e);
}
return file;
}
/**
* Create and add a new directory
* @param dir new directory
* @return file new directory
*/
public File createDir(File dir) throws DataUtilException {
if(dir == null) {
throw new DataUtilException("Dir parameter can not be a null value");
}
if(dir.exists()) {
throw new DataUtilException("Directory already exists: " + dir.getAbsolutePath());
}
if(! dir.mkdir()) {
throw new DataUtilException("The result of File.mkDir() was false. Failed to create directory. : "
+ dir.getAbsolutePath());
}
trackedFiles.add(dir);
return dir;
}
/**
* This is a convenience method to get a test resource by name. Test resources are not tracked since that could lead
* to their deletion.
* @param resourceName resource name
*/
public File getTestResource(String resourceName) {
URL url = this.getClass().getClassLoader().getResource(resourceName);
assert url != null : "Couldn't load : " + resourceName;
try {
return new File(url.toURI());
} catch (URISyntaxException e) {
throw new DataUtilException("Couldn't load test resource");
}
}
/**
* Delete all tracked files
*/
public void deleteAll() {
if(trackedFiles.size() == 0) {
return;
}
ArrayList<File> files = new ArrayList<File>(trackedFiles);
Collections.sort(files, filePathComparator);
for(File file : files) {
if(file.exists()) {
if(!file.delete()) {
throw new DataUtilException("Couldn't delete a tracked "
+ (file.isFile()? "file":"directory" + ": ") + file.getAbsolutePath());
}
}
}
trackedFiles.clear();
}
/**
* Tracked file count
* @return int number of tracked files
*/
public int size() {
return trackedFiles.size();
}
}