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how to provide relative address to read a file in java

what I want to ask seems so simple and crazy but since I am so beginner I dare to ask you guys.
I want to give relative address to read a file in eclipse java. my java file is in common package and json file is in resources package in the same project. but I do not know how to provide relative address to that.
BufferedReader in = new BufferedReader(new FileReader("/?/file.json"));
so I have a project:
> src/main/java
>com.project.cc.restful.common
>com.project.cc.restful.resources
any help?
thanks!

What you need is a path that is relative to your working directory. The working directory is a configurable parameter. In eclipse the default is usually the root folder of the project (not the source code folder!). It can be configured in the "Run Configurations.." menu.
To be sure, run your application once with System.out.println(System.getProperty("user.dir")) to see the absolute path to your working directory. Once you have that, use ../../Resources (or something similar) to get to the resources directory using a relative path.

How to get src/main/resources path from Java

I have some stuff under src/main/resources path.
Specifically I have a folder with report templates called reports.
I understand that when the application is deployed/run all files and folders under src/main/resources go to the classpath, namely my project's WEB-INF/classes.
This means that a folder WEB-INF/classes/reports will be created in my server.
Now I want to access my reports as paths, not as inputstream, because my reporting code in java supports a filepath and not an inputstream. So I have to be able to get the WEB-INF/classes/reports absolute path (or relative, I don't care as long as it is right).
Reading some answers regarding similar questions, I have already tried the following things:
getClass().getResource(".").getPath(); --> this returns the exact path of the class I am currently at in my classpath, namely: C:\Tools\JBoss Application Server 7.1.1\standalone\deployments\myProject.war\WEB-INF\classes\aaa\bbb\ccc\ddd
getClass().getClassLoader().getResource(".").getPath(); --> this returns: C:\Tools\JBoss Application Server 7.1.1\modules\sun\jdk\main\service-loader-resources, which is completely irrelevant.
I want something to return C:\Tools\JBoss Application Server 7.1.1\standalone\deployments\myProject.war\WEB-INF\classes
If it is not possible, I will get the first path and go as many folders back as needed to reach classes folder.
Thank you.

You need ServletContext.getRealPath(String) method.
getServletContext().getRealPath("/WEB-INF")

Java (maven web app), getting full file path for file in resources folder?

I'm working with a project that is setup using the standard Maven directory structure so I have a folder called "resources" and within this I have made a folder called "fonts" and then put a file in it. I need to pass in the full String file path (of a file that is located, within my project structure, at resources/fonts/somefont.ttf) to an object I am using, from a 3rd party library, as below, I have searched on this for a while but have become a bit confused as to the proper way to do this. I have tried as below but it isn't able to find it. I looked at using ResourceBundle but that seemed to involve making an actual File object when I just need the path to pass into a method like the one below (don't have the actual method call in front of me so just giving an example from my memory):
FontFactory.somemethod("resources/fonts/somefont.ttf");
I had thought there was a way, with a project with standard Maven directory structure to get a file from the resource folder without having to use the full relative path from the class / package. Any advice on this is greatly appreciated.
I don't want to use a hard-coded path since different developers who work on the project have different setups and I want to include this as part of the project so that they get it directly when they checkout the project source.
This is for a web application (Struts 1.3 app) and when I look into the exploded WAR file (which I am running the project off of through Tomcat), the file is at:
<Exploded war dir>/resources/fonts/somefont.ttf

Code:
import java.io.File;
import org.springframework.core.io.*;
public String getFontFilePath(String classpathRelativePath) {
Resource rsrc = new ClassPathResource(classpathRelativePath);
return rsrc.getFile().getAbsolutePath();
}
In your case, classpathRelativePath would be something like "/resources/fonts/somefont.ttf".

You can use the below mentioned to get the path of the file:
String fileName = "/filename.extension"; //use forward slash to recognize your file
String path = this.getClass().getResource(fileName).toString();
use/pass the path to your methods.

If your resources directory is in the root of your war, that means resources/fonts/somefont.ttf would be a "virtual path" where that file is available. You can get the "real path"--the absolute file system path--from the ServletContext. Note (in the docs) that this only works if the WAR is exploded. If your container runs the app from the war file without expanding it, this method won't work.

You can look up the answer to the question on similar lines which I had
Loading XML Files during Maven Test run
The answer given by BobG should work. Though you need to keep in mind that path for the resource file is relative to path of the current class. Both resources and java source files are in classpath

Absolute Path of Project's folder in Java

Lots of confusion in this topic. Several Questions have been asked. Things still seem unclear.
ClassLoader, Absolute File Paths etc etc
Suppose I have a project directory structure as,
MyProject--
--dist
--lib
--src
--test
I have a resource say "txtfile.txt" in "lib/txt" directory. I want to access it in a system independent way. I need the absolute path of the project.
So I can code the path as abspath+"/lib/Dictionary/txtfile.txt"
Suppose I do this
java.io.File file = new java.io.File(""); //Dummy file
String abspath=file.getAbsolutePath();
I get the current working directory which is not necessarily project root.
Suppose I execute the final 'prj.jar' from the 'dist' folder which also contains "lib/txt/txtfile.txt" directory structure and resource,It should work here too. I should absolute path of dist folder.
Hope the problem is clear.

You should really be using getResource() or getResourceAsStream() using your class loader for this sort of thing. In particular, these methods use your ClassLoader to determine the search context for resources within your project.
Specify something like getClass().getResource("lib/txtfile.txt") in order to pick up the text file.
To clarify: instead of thinking about how to get the path of the resource you ought to be thinking about getting the resource -- in this case a file in a directory somewhere (possibly inside your JAR). It's not necessary to know some absolute path in this case, only some URL to get at the file, and the ClassLoader will return this URL for you. If you want to open a stream to the file you can do this directly without messing around with a URL using getResourceAsStream.
The resources you're trying to access through the ClassLoader need to be on the Class-Path (configured in the Manifest of your JAR file). This is critical! The ClassLoader uses the Class-Path to find the resources, so if you don't provide enough context in the Class-Path it won't be able to find anything. If you add . the ClassLoader should resolve anything inside or outside of the JAR depending on how you refer to the resource, though you can certainly be more specific.
Referring to the resource prefixed with a . will cause the ClassLoader to also look for files outside of the JAR, while not prefixing the resource path with a period will direct the ClassLoader to look only inside the JAR file.
That means if you have some file inside the JAR in a directory lib with name foo.txt and you want to get the resource then you'd run getResource("lib/foo.txt");
If the same resource were outside the JAR you'd run getResource("./lib/foo.txt");

First, make sure the lib directory is in your classpath. You can do this by adding the command line parameter in your startup script:
$JAVA_HOME/bin/java -classpath .:lib com.example.MyMainClass
save this as MyProject/start.sh or any os dependent script.
Then you can access the textfile.txt (as rightly mentioned by Mark) as:
// if you want this as a File
URL res = getClass().getClassLoader().getResource("text/textfile.txt");
File f = new File(res.getFile());
// As InputStream
InputStream in = getClass().getClassLoader()
.getResourceAsStream("text/textfile.txt");

#Mark is correct. That is by far the simplest and most robust approach.
However, if you really have to have a File, then your best bet is to try the following:
turn the contents of the System property "java.class.path" into a list of pathnames,
identify the JAR pathname in the list based on its filename,
figure out what "../.." is relative to the JAR pathname to give you the "project" directory, and
build your target path relative to the project directory.
Another alternative is to embed the project directory name in a wrapper script and set it as a system property using a -D option. It is also possible to have a wrapper script figure out its own absolute pathname; e.g. using whence.

Config files - where to put them in Java?

I have a java desktop app and the issue of config files is vexing me.
What I want is for my distributable application folder to look like this:
MyApp/Application.jar
MyApp/SpringConfig.xml
MyApp/OtherConfig.xml
MyApp/lib
But at the moment SpringConfig.xml is inside Application.jar and I can't even find OtherConfig.xml programmatically.
I don't care how I set up the various files in my compilation path, so long as they end up looking like the above.
So..
where do i put the files in my dev setup?
and how do i access them programmatically?
thanks

the spring config file is related to the code and wiring of your application, hence it'd better be inside the jar, and should be subject to change by the users
(new File(".")).getAbsolutePath(); returns the absolute path of your jar - then you can load the OtherConfig.xml by a simple FileInputStream
if the SpringConfig.xml contains configuration data like database credentials, put them in an external application.properties and use a custom PropertyPlaceholderConfigurer to load the external file.
Answering the question "where do I put the files in my dev setup" is not possible because we don't know your environment.
Actually, if you want to be able to edit the config yourself (and not necessarily end-users), you can open the jar with any zip software (WinRAR for instance) and edit the config file from within the jar.
Update: as it seems you can't make the config files to be places out of the jar. Well, for a start, you can do it manually - whenever the .jar is complete, just remove the config file from inside and place it outside.

I typically create a structure where I have a src/ directory and then other directories exist at the same level. Some of those directories include:
lib/ - External Libraries
config/ - Configuration Files
resources/ - Various resources I use (images, etc)
At that same level, I then create an Ant script to perform my build so that the appropriate config files, resources, lib, etc are copied into my JAR file upon build. It has worked great for me up to this point and is a fairly easy to understand organizational structure.
Update: Accessing my config files is done, typically, by knowing their location and opening them up and reading them in the code. Because I use Ant to build, I make sure that my config files are in a location that I expect. So, for example, in a recent application I created, when I compile, my JAR file is in the top level directory (relative to the application release structure). Then, there is a "main" config file at that same level. And there is a "theme" config file that is in a themes folder.
To read the various files, I just open them up as I would any other file and read them in and go from there. It's nothing particularly fancy but it works well and it makes it easy to manually change configurations if I need to do so.

In dev mode, put them in source dir and they will be copied to your classes folder, you can then access them using classloader.
Example:
URL url = ClassLoader.getSystemResource("test.properties");
Properties p = new Properties();
p.load(new FileInputStream(new File(url.getFile())));
In Prod mode, you can make them part of your jar.