file not found exception in jar

Question

public class ABC {
    public ABC() {
        File file = new File("xyz.xml");

but when I run my jar as follows:

java -jar filename.jar arguments....

then it is showing error:

java.lang.IllegalArgumentException: InputStream cannot be null
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:120)
at com.ensarm.niidle.web.proxy.ABC.<init>(ABC.java:47)

How can I fix it?

Answer 1

If you need to read file content in JARs, you can not use File class directly. Using ClassLoader to load it:

// for example read the SeleniumConfiguration.xml in the default package

InputStream input = SeleniumConfiguration.class.getResourceAsStream("/SeleniumConfiguration.xml");

Answer 2

The NullPointerException is a clear indication that the file was not found.

InputStream input=ABC.class.getResourceAsStream("/Element.xml");

Where is your XML file? If you place it in the same package (directory inside the jar file) as ABC.class, then it should be Element.xml without the leading slash.

Answer 3

Normally you can use the InputStream as suggested, but incase you want to do further non-java operations on the file eg decrypting it using external application etc, you can use FileOutputStream to write this stream into a file and then use it's path as a correct file path. In simple words, you can unjar this file to your file system.

Answer 4

Did you put your xml file at the root of the jar file? If you use path like "/Element.xml", the jar file structure should be like:

jar-file

• com
• META-INF
• Element.xml