This question already has answers here:
How to read a file from jar in Java?
(6 answers)
How to read a text file inside a JAR? [duplicate]
(4 answers)
Closed 3 years ago.
I have class files and a text file wrapped up in a jar. This problem has been solved on the internet before, but when I try it I get a null pointer exception, or File f.exists() returns false. It should be noted that my code is not in a package. It should be noted that when help.txt is dropped in the same folder as the jar, then it works.
`MyClass z = new MyClass();
String helpPath = z.getClass().getClassLoader().getResource("help.txt").toString();
File f = new File(helpPath);
if (f.exists()){
Desktop d = Desktop.getDesktop();
d.open(f);`
It should also be noted that I have code written to open powershell and then java my class file, with no specified classpath.
` Runtime.getRuntime().exec(new String[]{"cmd","/c","start","powershell","-noexit","/c","java -jar \"" + filename + "\""});`
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This question already has answers here:
How to get the real path of Java application at runtime?
(15 answers)
Closed 6 years ago.
I'm trying to load a .txt file into an arrayList in java using a combination of relative paths.
My jar file is in /usr/tool/dist/tool.jar
The file I want to load is in /usr/tool/files/file.txt
I think I was able to retrieve the path of my tool.jar, but how can I go from that path to the one where my file is?
I have the following code
// String path should give me '/usr/tool'
File f = new File(System.getProperty("java.class.path"));
File dir = f.getAbsoluteFile().getParentFile();
String path = dir.toString();
String table1 = this should represent /usr/tool/files/file.txt
BufferedReader buf_table1 = new BufferedReader(new FileReader(new File(table1)));
To find the path of your jar file being executed, java.class.path is not the right property. This property may contain more than one file, and you cannot know which is the right one. (See the docs.)
To find the path of the correct jar file, you can use this instead:
URL url = MainClass.class.getProtectionDomain().getCodeSource().getLocation().getPath();
Where MainClass the main class of your tool, or any other class in the same jar file.
Next, the parent File of a file is its directory. So the parent File of /usr/tool/dist/tool.jar is /usr/tool/dist/. So if you want to get to /usr/tool/files/file.txt, you need to get the parent of the parent, and then from there files/file.txt.
Putting it together:
File jarFile = new File(MainClass.class.getProtectionDomain().getCodeSource().getLocation().getPath());
File file = new File(jarFile.getParentFile().getParent(), "files/file.txt");
This question already has answers here:
Read properties file outside JAR file
(8 answers)
How to get the path of a running JAR file?
(33 answers)
Closed 6 years ago.
I have a folder structured like this:
MyFolder:
file1.xml
file2.xml
project.jar
But if in a class I use:
File f = new File("file1.xml");
I receive an error, because it doesnt find the file. Why?
You should use a relative path in your code.
Example: File f = new File("./file1.xml");
If you are using Windows the code you posted will work, but not on Linux where the default parent file is your home.
But you can do in any OS by using:
public class MyClass {
public void loadFile() {
URL url = MyClass.class.getProtectionDomain().getCodeSource().getLocation();
File jar = new File(url.toURI());
File f = new File(jar.getParent(), "file1.xml");
//your code
}
}
PS: This needs to be inside project.jar because you are getting the location where you jar file is.
This question already has answers here:
java.io.FileNotFoundException: the system cannot find the file specified
(8 answers)
Closed 4 years ago.
My program get a filename in parameter but if i want to use it i need the full directory path or i get filenotfoundexception.
For example:
My program got sample.txt in parameter from C:\Users\me\documents.
File file = new File(args[0]);
FileReader fr = new FileReader(file);
That throw filenotfoundexception.
So what should i use to locate the file?
I saw so many similar question but i didnt find solution :(
I tried to use getResources and getPath but nothing.
You can open a file with just the filename if that file exists in the same directory as of your source code. If the file is located at any random location then you need to give the complete path of the file along with its name.
Eg: c:\documents\sample.txt
Or another thing that you can try is recursively going through all folders present in your file system and locate the file. However, this is will be a very horrible solution.
File fileName = new File("myfile.txt");
if(!fileName.exists()) {
fileName.createNewFile();
}
FileOutputStream oFile = new FileOutputStream(fileName, false);
add this code if your file is not on the location this will create a one for you then you wont be getting filenotfound exception at the latter part
This question already has answers here:
Rename a file using Java
(15 answers)
Closed 9 years ago.
I have file names like 323423233.
I want to add the last 2 digits of the file name and add it to the front and
make it 33/323423233 and add extension to it(like .doc).
What's a simple statement that I can use to achieve this?
This is 2013. This is Java 7. This is the time for Files and Path.
Base directory:
final Path baseDir = Paths.get("/path/to/baseDir");
Determine subdirectory for a file:
final String s = name.substring(name.length() - 2, name.length());
Create that directory:
final Path subDir = baseDir.resolve(s);
// Will not do anything if directory already exists...
// But will throw exception if unable to create
Files.createDirectories(subDir);
Write to the file:
final Path dst = subDir.resolve(name + ".doc");
Files.copy(src, dst);
Remove original:
Files.delete(src);
Or in one operation:
Files.move(src, dst);
This question already has answers here:
How to create a folder in Java?
(8 answers)
Closed 3 years ago.
I tried to use the File class to create an empty file in a directory like "C:/Temp/Emptyfile".
However, when I do that, it shows me an error : "already made folder Temp". Otherwise, it won't create one for me.
So, how do I literally create folders with java API?
Looks file you use the .mkdirs() method on a File object: http://www.roseindia.net/java/beginners/java-create-directory.shtml
// Create a directory; all non-existent ancestor directories are
// automatically created
success = (new File("../potentially/long/pathname/without/all/dirs")).mkdirs();
if (!success) {
// Directory creation failed
}
You can create folder using the following Java code:
File dir = new File("nameoffolder");
dir.mkdir();
By executing above you will have folder 'nameoffolder' in current folder.