I have a text file text.txt located in the classes output root directory.
When I use new File("text.txt"), i received the java.io.FileNotFoundException.
My output structure is liking
com
mycompany
test.class
text.txt
Anything wrong and how to fix?
When you don't give an absolute location for a file it searches from where you launched the program (your working directory). So, launch your application in the same directory as that file or move the file to where ever you are launching from.
If you want to read a file relative to your classpath however, you need to do something like this...
reader = new BufferedReader(new InputStreamReader(
getClass().getClassLoader().getResourceAsStream("test.txt")));
It will use the current working directory. From the Java documentation (http://download.oracle.com/javase/1.4.2/docs/api/java/io/File.html#File%28java.lang.String%29):
By default the classes in the java.io package always resolve relative pathnames against the current user directory. This directory is named by the system property user.dir, and is typically the directory in which the Java virtual machine was invoked.
new File("text.txt") is relative to your working directory. You could use this.getClass().getResourceAsStream("text.txt") to load a file from the classpath.
Related
Image DescriptionTrying to access a test.txt file that is in the same location as my HelloController.java file but for some reason, it is showing that the file does not exist. I've tried moving the file around but it does not work.
Using the absolute path works, but this is a shared project so it will be ran on other computers. Any suggestions would be much appreciated.
Your best bet is to add it to the class path and reading it as a class path resource.
The relative path root is your "working directory". Which means if you try to access "." you will start at your working directory. This directory is only set once for your application and is normally the folder which was opened when you started it.
When working with IDEs (like in your case) the working directory will be the root folder of your project (So the folder in which the pom.xml and src folders are located.
If you want to access the file via the normal file API you are currently using, just put the file in that diretory and it should work (given you share it with the other people in the same location).
If you need the file to be inside your generated output jar-file, you will need to use the File as a resource (See duffymo's answer), as the file does not exist by itself on the file system, but as a file inside your jar-file.
If you want to know your current working directory, you can create a File refrence to "." and expand it to an absolute path (Which will replace refrences like "." and ".." and generate a file path from your root) and then write it to the console. This would look something like this:
// Get refrence to the current working directory
File workingDirectoryReference = new File(".");
// Convert it to an absolute path string
String absolutePath = workingDirectoryReference.getAbsolutePath();
// Output to console
System.out.println(absolutePath );
I want to print the output in a file. I am using PrintWriter IO stream to add the data to file. When I want to check it, I don't know where the file is located. I am using Eclipse IDE.
PrintWriter writer=new PrintWriter("output.txt","UTF-8");
writer.println("Barcode Reader");
So can any one point me to where the file will be located?
I had this problem initially when I switched to using Eclipse. The current relative path is set to the project directory. The following code snippet will explain this better.
Path currentRelativePath = Paths.get("");
String myPath = currentRelativePath.toAbsolutePath().toString();
System.out.println("Current relative path is: " + myPath);
Note that the Path object is received from a get method in Paths((plural)). They are located in java.nio.file.
Further information about this can be found in the Path Operations page.
Does that solve your problem?
It will be present in your project's root folder.
Just open your project folder from your workspace using Explorer and it will be there.
With a filename like "output.txt" it will be placed into the current working directory.
Unless you specify otherwise, in Eclipse that will be the root directory of your project.
You may have to click "Refresh" for it to show up in the File Explorer.
If you give you file name directly like C:\java\workspace\ocpjp7 (a Windows
directory) or /home/nblack/docs (the docs directory of user nblack on UNIX), you can find your file in those directories. But if you don't give the full path, it will be in your current working directory.
"output.txt" -> root
"src/resources/output.txt" -> in resources package
At first you should create this file with File in directory you want.Next step to write data into the file. Your file will be located in directory you want , you set when file has created.
Also check this class FileInputStream
I'm programming Java in Eclipse IDE. Here is code I want to read file:
File file = new File("file.txt");
reader = new BufferedReader(new FileReader(file));
I put file.txt in two place:
1) same folder of this SOURCE file.
2) in bin\...\ (same folder of this CLASS file)
But I allways receive NO FILE FOUND.
Please help me.
thanks :)
If the file ships with your application, it would be better accessed as a resource than as a file. Simply copy it to somewhere in your build path and use Class.getResourceAsStream or ClassLoader.getResourceAsStream. That way you'll also be able to access it if you bundle your app as a jar file.
Currently, you're looking for the file relative to the process's current working directory, which could be entirely unrelated to where the class files are.
if you put the file under sources and inside the package "test" for example, the path is:
./src/test/file.txt
you can use
File file = new File("./src/test/file.txt");
System.out.println(file.exists());
The path ./bin/test/file.txt will work in the second case and is more suitable for a normal java project
Currently, in my eclipse project, I have a file that I write to. However, I have exported my project to a JAR file and writing to that directory no longer works. I know I need to treat this file as a classpath resource, but how do I do this with a BufferedWriter?
You shouldn't have to treat it as a classpath resource to write to a file. You would only have to do that if the file was in your JAR file, but you don't want to write to a file contained within your JAR file do you?
You should still be able to create and write to a file but it will probably be relative to the working directory - the directory you execute your JAR file from (unless you use an absolute path). In eclipse, configure the working directory from within the run configuration dialog.
You're probably working in Linux. Because, in Linux, when you start your application from a JAR, the working directory is set to your home folder (/home/yourname/). When you start it from Eclipse, the working directory is set to the project folder.
To make sure you really know the files you are using are located in the project folder, or the folder where your JAR is in, you can use this piece of code to know where the JAR is located, then use the File(File parent, String name) constructor to create your files:
// Find out where the JAR is:
String path = YourClass.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath();
path = path.substring(0, path.lastIndexOf('/')+1);
// Create the project-folder-file:
File root = new File(path);
And, from now on, you can create all your File's like this:
File myFile = new File(root, "config.xml");
Of course, root has to be in your scope.
Such resources (when altered) are best stored in a sub-directory of user.home. It is a reproducible path that the user should have write access to. You might use the package name of the main class as a basis for the sub-directory. E.G.
our.com.Main -> ${user.home}/our/com/
I'm working with text files on Java. On Ubuntu 10.
But, I'm having problems with path dir.
Example:
saveFile("textFile.txt","abc");
This abstract function basically put "abc" on "textFile.txt".
I compile this file, and create a jar file (using NetBeans).
When I run the app, and call saveFile("textFile.txt","abc"), textFile.txt is saved on \home. I don't want this. I want that textFile.txtgo to pathDir inside jar file.
How do I write in this file, this same way?
When reading resources from a JAR file, you cannot use the File API. Instead, you use Class.getResourceAsStream(), like this:
reader = new InputStreamReader(MyClass.class.getResourceAsStream(
"/apathdir/textFile.txt"), "UTF-8");
Note also how the encoding is specified. FileReader does not allow that, which is why it should usually be avoided.
Iwant to know, if fileName =
"textFile.txt", what is the path dir
of this file?
If you only use a bare file name (without giving a directory), the JVM will look for the file in the current directory of the JVM process; that is usually the directory you ran the JVM (the java executable) from.
how do i do to set
/apathdir/textFile.txt?. apathdir is a
directory that is inside jar file.
I tried: fileName = "/apathdir/textFile.txt", but doesn't works.
If you want to load a file from inside a JAR file, you cannot load it using FileReader. You need to use ClassLoader.getSystemResourceAsStream() (or Class.getResourceAsStream). See e.g. this article for an explanation:
http://www.devx.com/tips/Tip/5697