We Keep Coding

Use Relative path in place of absolute path

First of all i request people do not consider it as a duplicate question, please look into query.
I am copying the xml files from one folder to other folder, in the source folder, i have some files which have some content like "backingFile="$IDP_ROOT/metadata/iPAU-SP-metadata.xml" but while writing to the destination folder.
i am replacing the "$IDP_ROOT" with my current working directory. The entire copying of files is for deploying into tomcat
server. The copying is done only when server starts for the first time.
Problem: If i change the folder name from my root path in my machine after i run the server,
the entire process will be stopped because the destination folder files already contains the content which is with
existed files names or folder names.
So i want to change it to relative path instead absolute path. What is the best way to do it?
Please look at code below:
// Getting the current working directory
String currentdir = new File(".").getAbsoluteFile().getParent() + File.separator;
if(currentdir.indexOf("ControlPanel")!=-1){
rootPath=currentdir.substring(0, currentdir.indexOf("ControlPanel"));
}else{
rootPath=currentdir;
}
rootPath = rootPath.replace("\\", "/");
// target file in source folder is having "backingFile="$IDP_ROOT/metadata/iPAU-SP-metadata.xml"
String content = FileReaderUtil.readFile(targetFile,
rootPath + "Idp/conf");
content = updatePath(content, Install.rootPath
+ "IdP/IdPserver/metadata","$IDP_ROOT");
FileWriterUtil.writeToFile(Install.rootPath
+ "IdP/IdPserver/idp/conf", content,
targetFile);
// update method
public String updatePath(String content, String replaceString,String replaceKey) {
replaceKey = replaceKey!=null ? replaceKey : "$IDP_SERVER_ROOT";
replaceString= replaceString.replace("\\","/");
String updateContent = content.replace(replaceKey,
replaceString);
return updateContent;
}

Relative to absolute path in java

I have have a file that I want to use in my project which is in the resources package
src.res
Following what was stated in this answer, I believe that my code is valid.
File fil = new File("/res/t2.nii");
// Prints C:\\res\\t2.nii
System.out.println(fil.getAbsolutePath());
The problem is that I that file is in my projects file not there, so I get an Exception.
How am I suppose to properly convert from relative path to absolute?

Try with directory first that will provide you absolute path of directory then use file.exists() method to check for file existence.
File fil = new File("res"); // no forward slash in the beginning
System.out.println(fil.getAbsolutePath()); // Absolute path of res folder
Find more variants of File Path & Operations
Must read Oracle Java Tutorial on What Is a Path? (And Other File System Facts)
A path is either relative or absolute.
An absolute path always contains the root element and the complete directory list required to locate the file.
For example, /res/images is an absolute path.
A relative path needs to be combined with another path in order to access a file.
For example, res/images is a relative path. Without more information, a program cannot reliably locate the res/images directory in the file system.

Since you are using a Java package, you must to use a class loader if you want to load a resource. e.g.:
URL url = ClassLoader.getSystemResource("res/t2.nii");
if (url != null) {
File file = new File(url.toURI());
System.out.println(file.getAbsolutePath());
}
You can notice that ClassLoader.getSystemResource("res/t2.nii") returns URL object for reading the resource, or null if the resource could not be found. The next line convertes the given URL into an abstract pathname.
See more in Preferred way of loading resources in Java.

validate with
if (fil.exists()) { }
before and check if it really exist. if not then you can get the current path with
System.getProperty("user.dir"));
to validate that you are starting fromt he proper path.
if you really want to access the path you shouldnt use absolut pathes / since it will as explained start from the root of your Harddisk.
you can get the absolut path of the res folder by using this what my poster was writte in the previous answer:
File fil = new File("res");
System.out.println(fil.getAbsolutePath());

dynamic path in java application

I want to specify the path dynamically. myapp/CopyFolder and myapp/RunFolder's are inside application like myapp/WEB-INF. The code I have given below is in .java file(in eclipse) and in .class file(in tomcat inside myapp/WEB-INF/classname/packagename/). My deployment is in tomcat.
try {
functionNamesObject.Integration(
".txt",
path+"\\CopyFolder",
path+"\\RunFolder",
"app.exe",
"Input.txt"
);
I want path to be dynamic when I call above function. I tried with getResource("MyClass.class") ,new File("").getAbsolutePath(); and System.getProperty("user.dir") but no use. Is there any other way?

You can get the path value as below:
URL resource = getClass().getResource("/");
String path = resource.getPath();
This will return the absolute path to to your myApp/WEB-INF/classes directory.

File Exists in Java?

I trying to check whether a file exists at given directory location.
File seacrhFile = new File("D:/input", contract.conf);
if (seacrhFile.exists()) {
returnFile = seacrhFile;
} else {
System.out.println("No such file exists");
}
reutrn returnFile;
This is working in D:/input directory scenario, but if I Change the directory location to src/test/resources/input folder then I am getting No such file exists, eventhough the file exists.

If you want to have access to
src/test/resources/input
you probably should use
System.getProperty("user.dir") + File.separator + "src/test/resources/input"
because the system-property "user.dir" points to the projectlocation.
If you just use "src/test/resources/input" you will get your mentioned exception, because the File Object don't "start" at the project location. So you have to specify it manually.
Nevertheless it's better to use the getResource-Method to retrieve different resources within your project, because if you run your project with the jar-File you need to tweak around to get "user.dir" to work correctly.
Just a basic example for the Classloader:
ClassLoader.getSystemClassLoader().getResource("test/resources/input");
This returns an URL-Object, with this object you can get the File-Object using ...
URL filePath = ClassLoader.getSystemClassLoader().getResource("test/resources/input");
File file = new File( filePath.toURI() );

Remove the src and try it again .

Specifying a relative path in File in Java

I'm uploading images using Spring and Hibernate. I'm saving images on the server as follows.
File savedFile = new File("E:/Project/SpringHibernet/MultiplexTicketBooking/web/images/" + itemName);
item.write(savedFile);
Where itemName is the image file name after parsing the request (enctype="multipart/form-data"). I however need to mention the relative path in the constructor of File. Something like the one shown below.
File savedFile = new File("MultiplexTicketBooking/web/images/" + itemName);
item.write(savedFile);
But it doesn't work throwing the FileNotFoundException. Is there a way to specify a relative path with File in Java?

Try printing the working directory from your program.
String curDir = System.getProperty("user.dir");
Gets you that directory. Then check if the directories MultiplexTicketBooking/web/images/ exist in that directory.
Can't count the number of times I've been mistaken about my current dir and spent some time looking for a file I wrote to...

It seems the server should offer functionality as might be seen in the methods getContextPath() or getRealPath(String). It would be common to build paths based on those types of server related and reproducible paths. Do not use something like user.dir which makes almost no sense in a server.
Update
ServletContext sc=request.getSession().getServletContext();
File savedFile = new File(sc.getRealPath("images")+"\\" + itemName);
Rather than use "\\" I'd tend to replace that with the following which will cause the correct file separator to be used for each platform. Retain cross-platform compatibility for when the client decides to swap the MS/ISS based server out for a Linux/Tomcat stack. ;)
File savedFile = new File(sc.getRealPath("images"), itemName); //note the ','
See File(String,String) for details.

You could get the path of your project using the following -
File file = new File("");
System.out.println("" + file.getAbsolutePath());
So you could have a constants or a properties file where you could define your path which is MultiplexTicketBooking/web/images/ after the relative path.
You could append your path with the path you get from file.getAbsolutePath() and that will be the real path of the file. - file.getAbsolutePath() + MultiplexTicketBooking/web/images/.
Make sure the folders after the Project path i.e. MultiplexTicketBooking/web/images/ exist.

You can specify the path both absolute and relative with File. The FileNotFoundException can be thrown because the folder might be there. Try using the mkdirs() method first in to create the folder structure you need in order to save your file where you're trying to save it.