Develop Reference

Java: How to get path of a file when running JAR file

When I use relative path, I can run my Java program from Eclipse. But when I run it as a JAR file, the path doesn't work anymore. In my src/components/SettingsWindow.java I have:
ObjectInputStream ois = new ObjectInputStream(new FileInputStream("./src/files/profile.ser"));
I get a FileNotFoundException.
My file directory looks like this:
file directory
What I've tried:
String filePath = this.getClass().getResource("/files/profile.ser").toString();
String filePath = this.getClass().getResource("/files/profile.ser").getPath();
String filePath = this.getClass().getResource("/files/profile.ser").getFile().toString();
And I'd just put filePath in new FileInputStream(filePath) but none of these work and I still get a FileNotFoundException. When I System.out.println(filePath) it says: files/profile.ser
I'm trying to get the path of src/files/profile.ser while I'm in src/components/SettingsWindow.java

You can get the URL to the class:
String path =
String.join("/", getClass().getName().split(Pattern.quote(".")))
+ ".class";
URL url = getClass().getResource("/" + path);
which will either yield "file:/path/to/package/class.class" or "jar:/path/to/jar.jar!/package/class.class". You either can work with the URL or use
JarFile jar =
((JarURLConnection) url.openConnection()).getJarFile();
and use jar.getName() to get the path to parse to get your installation directory.

To get the current JAR file path I use:
public static String getJarFilePath() throws FileNotFoundException {
String path = getClass().getResource(getClass().getSimpleName() + ".class").getFile();
if(path.startsWith("/")) {
throw new FileNotFoundException("This is not a jar file: \n"+path);
}
if(path.lastIndexOf("!")!=-1) path = path.substring(path.lastIndexOf("!/")+2, path.length());
path = ClassLoader.getSystemClassLoader().getResource(path).getFile();
return path.substring(0, path.lastIndexOf('!')).replaceAll("%20", " ");
}

File is not deleted when file path is generated dynamically

I am facing a problem but have not able to solve it yet. Let me share what I have done till now. I tried to delete a file using java.nio.file packages. And below is my code.
// directory will be dynamically generated.
String directory = fileDirectory+ "//" + fileName;
Path path = Paths.get(directory);
if (Files.exists(path)) {
Files.delete(path);
}
I generated the path correctly. But when Files.exists(path) calls it return false. That's why file is not deleted. But if I generated the directory string by hard-coded than it works perfectly.
// hard-coded directory works perfectly.
String directory = "C://opt//tomcat//webapps//resources//images//sprite.jpg";
I also tried the another method Files.deleteIfExists(path);. Which check the both the file existence and delete the file.
The other packages org.apache.commons.io.FileUtils and java.io.File have tried. But can't resolve the issue.
Note: My application is in spring-boot. And I read the directory from the application.properties file for both save images and delete images.
EDIT:
file uploading I mean save into the directory is perfectly worked. But file deletion does not work.
application.properties
image.root.dir=images
image.root.save.dir=C:/opt/tomcat/webapps/resources/
in implementation file
#Value("${image.root.dir}")
private String UPLOADED_FOLDER;
#Value("${image.root.save.dir}")
private String saveDir;
String directory = saveDir + UPLOADED_FOLDER + "/" + fileName;
save file into directory
String directory = saveDir + UPLOADED_FOLDER + "/";
try {
byte[] bytes = file.getBytes();
Path path = Paths.get(directory);
if (!Files.exists(path)) {
Files.createDirectories(path);
}
path = Paths.get(directory, file.getOriginalFilename());
Files.write(path, bytes);
} catch (IOException e) {
logger.error("save image into directory : " + e);
}

String directory = fileDirectory+ "//" + fileName;
This is not the correct separator used between a directory and a file name, though it seems to work as well.
This means the problem is not the separator, but a mismatch between the code that you use to generate the path and this code. You're generating the directory into somewhere else than where this is pointing.

Java, get full path of file and removing filename

I'm trying to get the directory path to a file. The issue I am having is getting the last \ or / of the directory. As this code is supposed to work on all operating systems, I can't seem to find any solution for this. Any help is appreciated.
My code so far:
System.out.print("Enter dir: ");
String path = kb.nextLine();
File pathes = new File(path);
String path2 = pathes.getParent();
path = path.substring(0, path.lastIndexOf("\\")+1);
System.out.println("PATH: " + path);
System.out.println("PATH2: "+path2);
My output is:
PATH: C:\Users\User\Desktop\test\
PATH2: C:\Users\User\Desktop\test
This is just test code and not the real code I'm working on.
EDIT
What I'm trying to get is
C:\Users\User\Desktop\test\
from
C:\Users\User\Desktop\test\test.txt

To get the absolute path to the parent directory you can do:
File f = new File("C:\\Users\\User\\Desktop\\test\\test.txt");
String path = f.getParentFile().getAbsolutePath();
System.out.println(path);
Output:
C:\Users\User\Desktop\test
If you really want the trailing slash, then you can just append File.separator:
File f = new File("C:\\Users\\User\\Desktop\\test\\test.txt ");
String path = f.getParentFile().getAbsolutePath() + File.separator;
System.out.println(path);
Output:
C:\Users\User\Desktop\test\

Telling .jar file to make a file on the Desktop instead of within itself (java) mac

I have a program which includes the following line of code:
//String s = fileName;
File location = new File(s);
and then I have
//String contents = whatIWantToPrint;
OutputStream print = new FileOutputStream(location);
print.write(contents.getBytes());
print.close();
telling the program to print the string contents to the file s. However the file appears within the folder that the program is in rather than the directory in which the program is in. For example if the program is on the persons desktop I want it to make the file on their desktop.
I used the following line in terminal to make the program a jar file (mac):
jar -cvmf manifest.txt Generate.jar *.class
Someone told me to do this:
String dir = System.getProperty("home.dir"+"/Desktop");
String filePath = dir + File.separator + ss + ".txt";
File location = new File(filePath);
But I'm not sure if that's what will make the program make the file in the desktop and it also throws a security exception so it doesn't work anyways

You should do:
String s= System.getProperty("user.home");
and append path separator and file name
String filePath = s + File.separator + "desktop" + File.separator + "myFile.txt";

You could try this
String DEFAULT_USER_DIR = System
.getProperty("user.home"+"/Desktop");
File location = new File(DEFAULT_USER_DIR);
user.dir returns User's current working directory
See the javadoc here.

Weird exception in thread "main" java.io.FileNotFoundException I/O Java

I have this error when I am trying to read the file:
Exception in thread "main" java.io.FileNotFoundException: \src\product.txt (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:120)
at dao.Inventory.readFile(Inventory.java:30)
at view.InventoryView.init(InventoryView.java:33)
at view.InventoryView.<init>(InventoryView.java:21)
at view.InventoryView.main(InventoryView.java:211)
But the thing is, I have the product.txt in my src folder.
My code is the following:
public void readFile() throws IOException {
// input file must be supplied in the first argument
InputStream istream;
File inputFile = new File("\\src\\product.txt");
istream = new FileInputStream(inputFile);
BufferedReader lineReader;
lineReader = new BufferedReader(new InputStreamReader(istream));
String line;
while ((line = lineReader.readLine()) != null) {
StringTokenizer tokens = new StringTokenizer(line, "\t");
// String tmp = tokens.nextToken();
// System.out.println("token " + tmp);
ActionProduct p = new ActionProduct();
prodlist.add(p);
String category = p.getCategory();
category = tokens.nextToken();
System.out.println("got category " +category);
int item = p.getItem();
item = Integer.parseInt(tokens.nextToken());
String name = p.getName();
System.out.println("got name " +name);
double price = p.getPrice();
price = Double.parseDouble(tokens.nextToken());
int units = p.getUnits();
units = Integer.parseInt(tokens.nextToken());
}
}
I don't think anything is wrong with my code. Also, I saw a similar post about a hidden extension like FILE.TXT.TXT, how would you show a hidden extension in MacOSX?? Any suggestions? (Would there be any other problem besides the hidden extension issue?)

/src/product.txt is an absolute path, so the program will try to find the file in the src folder of your root path (/). Use src/product.txt so the program will use this as a relative path.

It's possible (most likely?) that your Java code is not executing inside the parent folder of src, but instead inside a 'class' or a 'bin' folder with the compiled java .class files.
Assuming that 'src' and 'bin' are in the same directory, you could try ..\\src\\product.txt
See also http://en.wikipedia.org/wiki/Path_(computing)

As other commenters stated, the path is absolute and points to
\src\product.txt which is (hopefully) not where
your sources are stored.
The path separator should be set in an OS-independent manner using
the System.getProperty("path.separator") property. On a Unix system, you'll have trouble with hard coded backslashes as path separators. Keep it portable!
String pathSeparator = System.getProperty("path.separator");
String filePath = "." + pathSeparator + "src" + pathSeparator + "product.txt";
File file = new File(filePath);
or better yet:
// this could reside in a non-instantiable helper class somewhere in your project
public static String getRelativePath(String... pathElements) {
StringBuilder builder = new StringBuilder(".");
for (String pathElement : pathElements) {
builder.append(System.getProperty("path.separator");
builder.append(pathElement);
}
return builder.toString();
}
// this is where your code needs a path
...
new File(getRelativePath("src", "product.txt");
...