I specified the full path of the file location when I created a FileWriter, but I did not see the file being created. I also did not get any error during file creation.
Here's a snippet of my code:
public void writeToFile(String fullpath, String contents) {
File file = new File(fullpath, "contents.txt");
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
BufferedWriter bw = new BufferedWriter(new FileWriter(file.getAbsoluteFile()));
bw.write(contents);
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
fullpath is "D:/codes/sources/logs/../../bin/logs".
I have searched my whole directory, but I cannot find the file anywhere.
If I specify just the filename only [File file = new File("contents.txt");] , it is able to save the contents of the file, but it is not placed on my preferred location.
How can I save the file content to a preferred location?
UPDATE:
I printed the full path using file.getAbsolutePath(), and I am getting the correct directory path. [D:\codes\sources\logs....\bin\logs\contents.txt] But when I look for the file in directory, I cannot find it there.
Make sure you add trailing backslashes to the path parameter so the path is recognized as a directory. The example provide is for a Windows OS which uses backslashes that are escaped. For a more robust method use the file.separator property for the system.
Works
writeToFile("D:\\Documents and Settings\\me\\Desktop\\Development\\",
"this is a test");
Doesn't Work
writeToFile("D:\\Documents and Settings\\me\\Desktop\\Development",
"this is a test");
File Separator Example
String fs = System.getProperty("file.separator");
String path = fs + "Documents and Settings" + fs + "me" + fs
+ "Desktop" + fs + "Development" + fs;
writeToFile(path, "this is a test");
Related
I am using this method to generate some turtle files .ttl in a sub-directory of my project:
public static void write(int id, int depth){
try {
FileWriter fw = null;
switch (getName()){
case ("KG1"):
fw = new FileWriter("WWW/KG1/" + depth + "/" + id + ".ttl");
break;
case ("KG2"):
fw = new FileWriter("WWW/KG2/" + depth + "/" + id + ".ttl");
}
// Write something
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
But I am having this exception when I have put my project in Ubuntu (it is still working fine in Windows) in the java class FileWriter:
java.io.FileNotFoundException: /WWW/KG1/2/0.ttl (No such file or directory)
I am using Eclipse Neon for both OSs, but it seems that Ubuntu is not happy about it.
Here is what I have tried so far:
Adding write permissons to ALL files and directories under the main project directory
Using absolute path instead of relative path, by using System.getProperty("usr.dir"), and plotting all the path string I am giving to FileWriter, but it does not work.
Any advice?
Thanks!
You can make things easier for yourself by using Path and File objects. Here is a version that optionally creates the wanted directory if it doesn't exist
Path path = Paths.get("WWW", "KG1", String.valueOf(depth));
try {
Files.createDirectories(path);
FileWriter fw = new FileWriter(new File(path.toFile(), id + ".ttl"));
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
Note that I intentionally skipped the switch to simplify the answer
I would try using File.separator and make sure the parent directory exists.
Here is an example (may have syntax issues).
final String WWW = "WWW";
final String KG1 = "KG1";
final String KG2 = "KG2";
final String extension = ".ttl";
int id = 1;
int depth = 1;
String filePath = "." // current dir
+ File.separator
+ WWW
+ File.separator
+ KG1
+ File.separator
+ depth
+ File.separator
+ id
+ extension;
File file = new File(filePath);
// make sure parent dir exists (else created)
file.getParentFile().mkdirs();
FileWriter writer = new FileWriter(file);
**I am trying to save and get Player objects from a Textfile and it works when using my IDE but when i create a Jar it can't find the text File. I tried with
this.getClas().getResources(path)
But still it didnt find the path to my text file.Can anybody Help?
public void setPlayer() throws FileNotFoundException {
ArrayList<Player> playerArrayList = new ArrayList<>();
playerArrayList = getPlayers();
Player player = new Player();
player.name = ViewManager.name;
player.score = Collision.points;
playerArrayList.add(player);
try{
FileOutputStream fileOut = new FileOutputStream("src/resources/highscore.txt");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
for(Player player1 : playerArrayList){
out.writeObject(player1);
}
out.close();
fileOut.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
ยดยดยดยด
Resource files are not physical Files, as they can be inside a jar. They are intended to be read-only, and the class loader may cache them. They are case sensitive, with / as path separator and there path starts at the class path's root, probably src/resources.
So use the resource file as fall back resource to copy, if some physical file does not exist.
Path appDir = Paths.get(System.getProperty("user.home") + ".myapp");
Files.createDirectories(appDir);
Path file = appDir.resolve("highscore.txt");
if (!Files.exists(file)) {
// Copy resource to file, either:
URL url = getClass().getResource("/highscore.txt");
Path templatePath = Paths.get(url.toURI());
Files.copy(templatePath, file);
// Or
InputStream templateIn = getClass().getResourceAsStream("/highscore.txt");
Files.copy(templateIn, file);
}
try (FileOutputStream out = Files.newOutputStream(file)) {
...
}
Path is the generalisation of File.
I don't know what IDE you're using, but you're writing the file to the source sub directory. That directory might not be included in the jar.
The condition is if the directory exists it has to create files in that specific directory without creating a new directory.
The below code only creates a file with the new directory but not for the existing directory . For example the directory name would be like "GETDIRECTION":
String PATH = "/remote/dir/server/";
String fileName = PATH.append(id).concat(getTimeStamp()).append(".txt");
String directoryName = PATH.append(this.getClassName());
File file = new File(String.valueOf(fileName));
File directory = new File(String.valueOf(directoryName));
if (!directory.exists()) {
directory.mkdir();
if (!file.exists() && !checkEnoughDiskSpace()) {
file.getParentFile().mkdir();
file.createNewFile();
}
}
FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);
bw.write(value);
bw.close();
Java 8+ version:
Files.createDirectories(Paths.get("/Your/Path/Here"));
The Files.createDirectories() creates a new directory and parent directories that do not exist. This method does not throw an exception if the directory already exists.
This code checks for the existence of the directory first and creates it if not, and creates the file afterwards. Please note that I couldn't verify some of your method calls as I don't have your complete code, so I'm assuming the calls to things like getTimeStamp() and getClassName() will work. You should also do something with the possible IOException that can be thrown when using any of the java.io.* classes - either your function that writes the files should throw this exception (and it be handled elsewhere), or you should do it in the method directly. Also, I assumed that id is of type String - I don't know as your code doesn't explicitly define it. If it is something else like an int, you should probably cast it to a String before using it in the fileName as I have done here.
Also, I replaced your append calls with concat or + as I saw appropriate.
public void writeFile(String value){
String PATH = "/remote/dir/server/";
String directoryName = PATH.concat(this.getClassName());
String fileName = id + getTimeStamp() + ".txt";
File directory = new File(directoryName);
if (! directory.exists()){
directory.mkdir();
// If you require it to make the entire directory path including parents,
// use directory.mkdirs(); here instead.
}
File file = new File(directoryName + "/" + fileName);
try{
FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);
bw.write(value);
bw.close();
}
catch (IOException e){
e.printStackTrace();
System.exit(-1);
}
}
You should probably not use bare path names like this if you want to run the code on Microsoft Windows - I'm not sure what it will do with the / in the filenames. For full portability, you should probably use something like File.separator to construct your paths.
Edit: According to a comment by JosefScript below, it's not necessary to test for directory existence. The directory.mkdir() call will return true if it created a directory, and false if it didn't, including the case when the directory already existed.
Trying to make this as short and simple as possible. Creates directory if it doesn't exist, and then returns the desired file:
/** Creates parent directories if necessary. Then returns file */
private static File fileWithDirectoryAssurance(String directory, String filename) {
File dir = new File(directory);
if (!dir.exists()) dir.mkdirs();
return new File(directory + "/" + filename);
}
I would suggest the following for Java8+.
/**
* Creates a File if the file does not exist, or returns a
* reference to the File if it already exists.
*/
public File createOrRetrieve(final String target) throws IOException {
final File answer;
Path path = Paths.get(target);
Path parent = path.getParent();
if(parent != null && Files.notExists(parent)) {
Files.createDirectories(path);
}
if(Files.notExists(path)) {
LOG.info("Target file \"" + target + "\" will be created.");
answer = Files.createFile(path).toFile();
} else {
LOG.info("Target file \"" + target + "\" will be retrieved.");
answer = path.toFile();
}
return answer;
}
Edit: Updated to fix bug as indicated by #Cataclysm and #Marcono1234. Thx guys:)
code:
// Create Directory if not exist then Copy a file.
public static void copyFile_Directory(String origin, String destDir, String destination) throws IOException {
Path FROM = Paths.get(origin);
Path TO = Paths.get(destination);
File directory = new File(String.valueOf(destDir));
if (!directory.exists()) {
directory.mkdir();
}
//overwrite the destination file if it exists, and copy
// the file attributes, including the rwx permissions
CopyOption[] options = new CopyOption[]{
StandardCopyOption.REPLACE_EXISTING,
StandardCopyOption.COPY_ATTRIBUTES
};
Files.copy(FROM, TO, options);
}
Simple Solution using using java.nio.Path
public static Path createFileWithDir(String directory, String filename) {
File dir = new File(directory);
if (!dir.exists()) dir.mkdirs();
return Paths.get(directory + File.separatorChar + filename);
}
If you create a web based application, the better solution is to check the directory exists or not then create the file if not exist. If exists, recreate again.
private File createFile(String path, String fileName) throws IOException {
ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource(".").getFile() + path + fileName);
// Lets create the directory
try {
file.getParentFile().mkdir();
} catch (Exception err){
System.out.println("ERROR (Directory Create)" + err.getMessage());
}
// Lets create the file if we have credential
try {
file.createNewFile();
} catch (Exception err){
System.out.println("ERROR (File Create)" + err.getMessage());
}
return file;
}
A simple solution using Java 8
public void init(String multipartLocation) throws IOException {
File storageDirectory = new File(multipartLocation);
if (!storageDirectory.exists()) {
if (!storageDirectory.mkdir()) {
throw new IOException("Error creating directory.");
}
}
}
If you're using Java 8 or above, then Files.createDirectories() method works the best.
I am trying to use file.delete() but it does not delete file ? I tested it on linux it delete files but on windows it does not delete file why..?
code :
private File getFiletobeUpload(File foto) {
boolean errorRename = true;
File uploadFile = null;
File testFile = foto;
String subdirname = this.checkDir(foto);
if (testFile.canWrite()) {
uploadFile = new File(AppConstants.PHOTOPATH + "/" + subdirname + "/" + testFile.getName());
try {
FileInputStream origStream = new FileInputStream(testFile);
FileOutputStream outStream = new FileOutputStream(uploadFile);
origStream.getChannel().transferTo(0, testFile.length(), outStream.getChannel());
origStream.close();
origStream = null;
outStream.close();
outStream = null;
} catch (Exception e) {
this.errorString += "error while writing to orig dir";
logger.error(e);
}
errorRename = !testFile.delete();
if (errorRename) {
this.errorString += "error while deleting the file";
}
}
testFile = null;
return uploadFile;
}
your code seems a bit odd, you are checking "testFile" for write access but then actually reading from it (FileInputStream). Is the first try/catch block running without exception? Maybe you should check if the file even exists:
System.out.println("File exists: "+testFile.exists());
errorRename = !testFile.delete();
Also if you just want to rename a file, use:
file.renameTo(File dest)
A general suggestion: consider using the classes in the java.nio package to your file IO if you can (not sure which version of Java you're running with) because the error handling is improved and you should be able to find a more specific reason for the failure based on the type of exception thrown and the exception message.
As per API, the disk-drive specifier - "/" for the UNIX root directory, and "\\" for a Microsoft Windows UNC pathname.
so for windows:
uploadFile = new File(AppConstants.PHOTOPATH + "\\" + subdirname + "\\" + testFile.getName());
I have a method
public void save(String filename)
{
try
{
BufferedWriter bw = new BufferedWriter(new FileWriter(new File(filename)));
for(Track item : thePlayList)
{
item.save(bw);
}
bw.close();
}
catch (Exception e)
{
System.out.println("couldn't save M3U file " + filename);
}
and I have this in the main method, I would like to know where does the saved file go ? if not then how to save the file in a specific folder.
combine.save("combined");
When specified without a path, Java is going to write the file into the working directory. You can always determine where that is with something like this
File file = new File(filename);
System.out.println(file.getCanonicalPath()); // <-- should print the full path to the file
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
You can also specify a full path when you call your method, for example -
combine.save("C:/combined"); // <-- or C:\\combined
or a relative path, for example -
combine.save("./output/combined"); // <-- or ../output/combined
The file will be saved in within the execution context of the application - in other words, the directory you ran it from...
For example...
If you ran the program from C:\MyJavaProgram, then it will be saved within this directory