Getresourceasstream() Is Always Returning Null

getResourceAsStream returns null

Lifepaths.class.getClass().getResourceAsStream(...) loads resources using system class loader, it obviously fails because it does not see your JARs

Lifepaths.class.getResourceAsStream(...) loads resources using the same class loader that loaded Lifepaths class and it should have access to resources in your JARs

getResourceAsStream() is always returning null

To my knowledge the file has to be right in the folder where the 'this' class resides, i.e. not in WEB-INF/classes but nested even deeper (unless you write in a default package):

net/domain/pkg1/MyClass.java  
net/domain/pkg1/abc.txt

Putting the file in to your java sources should work, compiler copies that file together with class files.

Why would ClassLoader.getResourceAsStream() return null?

I solved the mystery.

The key to solving was embedding some diagnostic logging when propertiesStream is null:

String classpath = System.getProperty("java.class.path");
LOG.info("CLASSPATH: " + classpath);
ClassLoader loader = MyClientMain.class.getClassLoader();
System.out.println("ClassLoader resource path: " + loader.getResource("resource.properties"));                    

So when I run with the original

contextClassLoader.getResourceAsStream("resource.properties")

I receive the null pointer condition, printing:

  INFO: CLASSPATH: myproj.one-jar.jar
  ClassLoader resource path: null

.

I then started suspecting something related to the "jar within a jar" as this is what the com.simontuffs.onejar essentially does (i.e. wrapping my project's jar inside a jar that contains all other library jars), so I opened myproj.one-jar.jar with 7-Zip and noted the full (absolute) path of "resource.properties":

myproj.one-jar.jar\main\myproj.jar\webapp\WEB-INF\classes\resource.properties

.

So I modified getResource("resource.properties") to:

 getResource("/main/myproj.jar/webapp/WEB-INF/classes/resource.properties")

which didn't fix the problem but printed the following upon the null pointer condition:

INFO: CLASSPATH: myproj.one-jar.jar
ClassLoader resource path: jar:file:/myproj.one-jar.jar!/main/myproj.jar!//main/myproj.jar/webapp/WEB-INF/classes/resource.properties

.

Then... divine intervention fell upon me and I had the insight (not reading any documentation that could even hint this, I swear!) that I should be using this path instead:

 getResource("/webapp/WEB-INF/classes/resource.properties")

And Voila! It works.

Whew.

getClass() getResource returning null

Replace this.getClass().getResource("res/bg.jpg") with this.getClass().getResource("../res/bg.jpg")

Since this.getClass().getResource("/") returns file:/C:/Users/cmooney/eclipse-workspace/TextSimplifier/bin/, you need to go one level(directory) up in the directory structure so that you can enter the res directory. It's like cd ../res from the current location of file:/C:/Users/cmooney/eclipse-workspace/TextSimplifier/bin/

Note: I can't see bg.jpg in the screenshot that you have attached. Make sure, you have bg.jpg in this path.

getResourceAsStream returning null despite called file being in same dir as class getResourceAsStream is called in

Created a dir called resources under /src/main/ and placed AwsCredentials.properties there and used

properties.load( PropertyLoader.class.getClassLoader().getResourceAsStream( "AwsCredentials.properties" ) );

instead of

properties.load( this.getClass().getResourceAsStream("AwsCredentials.properties" ) );

Not as elegant as I would like, but it works.

GetResourceAsStream returning null, file exists

You appear to be using the wrong ClassLoader. Invoking context.class.getClassLoader() provides the ClassLoader with which the ServletContext class (context.class) was loaded. What you want is the ClassLoader for the web application's classes, which would be context.getClassLoader().

getResourceAsStream returning null in Java 10

I found a solution although I don't entirely understand why this works an the problematic line doesn't, but this works:

Application.class.getResourceAsStream("/application.properties")

where Application is just a class in my app.

Maybe this is related to the answer pointed to by ochi, and Application.class is using my class loader and appProperties.getClass() is using the system class loader. But why does it behave differently on differently on Java 8 vs 10 is not something that is apparent.

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