Properties file javax.usb.properties not found error

[DineshDevaraj]

I tried to run the javax DumpDevices.java example application. I am getting Properties file javax.usb.properties not found error. But I have created the file in the same path. The structure of the directory, content of the file and Java version all are shared below.

mintty> ls -l
total 8
-rw-r--r-- 1 Dinesh Administrators 2739 Apr 29 20:10 DumpDevices.class
-rw-r--r-- 1 Dinesh Administrators 3355 Apr 29 20:10 DumpDevices.java
-rw-r--r-- 1 Dinesh Administrators 49 Apr 29 20:11 javax.usb.properties
mintty>
mintty> cat javax.usb.properties
javax.usb.services = org.usb4java.javax.Services
mintty>
mintty> java DumpDevices
Exception in thread "main" javax.usb.UsbException: Properties file javax.usb.properties not found.
at javax.usb.UsbHostManager.setupProperties(Unknown Source)
at javax.usb.UsbHostManager.getProperties(Unknown Source)
at javax.usb.UsbHostManager.createUsbServices(Unknown Source)
at javax.usb.UsbHostManager.getUsbServices(Unknown Source)
at DumpDevices.main(DumpDevices.java:94)
mintty> java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b18)
Java HotSpot(TM) Client VM (build 25.66-b18, mixed mode)
mintty> javac -version
javac 1.8.0_66
mintty>

[SKART1]

To use the usb4java implementation you have to create a file named javax.usb.properties in the root of your class path with the following content

Classpath:wiki

[kayahr]

Can't reproduce this. If you still have this problem then please give us more information like operating system, current directory name and the content of the CLASSPATH environment variable

[redfieldp]

I think you either need to make the documentation clearer, or address this as a bug. When you download the javax USB jar, and the javax examples repo, I cannot find a location for the properties file that circumvents this error. Whether it's added to a build path in Eclipse, locally copied into the classpath of the examples, or referenced via the classpath command line argument, I get the exception mentioned above. Can you clarify where the library is expecting this file to be in order to make it work? As far as I can tell none of the typical ways of including a file in the classpath successfully circumvent this issue.

[kayahr]

As SKART1 already quoted from the documentation two years ago, it simply has to be in the root of the class path. I'm sorry, I don't know how to describe it more clearer. How to configure your class path depends on your IDE, build tool or packager or what ever you use to bundle your application. I can't describe every possible environment in the world.

Here is a little command-line example using the DumpDevices program from the examples project:

$ tree
.
├── classes
│   ├── javax.usb.properties
│   └── org
│       └── usb4java
│           └── javax
│               └── examples
│                   └── DumpDevices.class
└── lib
    ├── commons-lang3-3.8.1.jar
    ├── libusb4java-1.3.0-linux-x86-64.jar
    ├── usb4java-1.3.0.jar
    ├── usb4java-javax-1.3.0.jar
    └── usb-api-1.0.2.jar

6 directories, 13 files

I can successfully run the example program with this command:

$ java -cp classes:lib/usb-api-1.0.2.jar:lib/usb4java-1.3.0.jar:lib/usb4java-javax-1.3.0.jar:lib/commons-lang3-3.8.1.jar:lib/libusb4java-1.3.0-linux-x86-64.jar org.usb4java.javax.examples.DumpDevices

As you can see the classpath is set to the classes directory and also contains all the needed JAR files. I placed the properties file in the classes directory and it works.

I don't know why it is not working for you or DineshDevaraj. That's why I asked for more information, especially about the classpath configuration.

[redfieldp]

I attempted the setup you outline here, and still got the same error.

The only solution that I could find was one suggested on a StackOverflow thread, suggesting adding the properties file to the root of usb4java-javax-1.3.0.jar. Once you do that it's possible to run the examples.

I'm not sure what's different about your setup, but I would suggest either testing on a clean VM/environment and seeing what works and doesn't work, or distributing your examples with the library distro, in a source tree format that you know will work on download.

[kayahr]

Well, when a very simple project structure works for me but not for you then there is no sense distributing examples with a specific structure because it still may work for me but not work for you for whatever strange unexpected reasons unknown to me. That's why the example simply is a standard Maven project. It just shows how to use usb4java and not how to package and deploy an application because that's up to you.

There is nothing special about my setup but I'm sure you think the same about yours. I would be very surprised if I accidentally configured some magic stuff to make it work on the eight VMs used to test usb4java every night and the three Raspis where I manually tested it before I published the last release.

Maybe we could do this the other way around and you give me a detailed reproduction? The crucial missing information from DineshDevaraj's original issue is the content of the CLASSPATH variable. The output suggests that there MUST be some configuration because otherwise the executed test program couldn't even find the usb-api jar. So I can't see whats going on there because lack of more detailed information. Now you seem to have the same problem but I have absolute no details on your case. Maybe you could attach a ZIP with your test project, the content of the CLASSPATH variable and the exact command you use to execute the test program (Or add a shell script/batch file to the ZIP containing that stuff)? And tell me which Java version and operating system you are using. Hopefully I'm then able to reproduce this and can tell you what's going wrong.

[redfieldp]

I'm happy to pull together that information, but am under a deadline. Keep this bug open and I'll clarify by the end of the month when I have a little more time.

In the meantime, do you have the command input for the "javac" step of the process? I'm wondering if this could be an issue.

[kayahr]

No haste. But this bug report is already closed and I think it will stay that way. Reason is that this can't be a bug in usb4java because this property file isn't read by usb4java. So the problem occurs before usb4java is even used. The file is read by the official USB API to decide which implementation to use and usb4java is just the implementation for this API. But I'm still interested to find out what strange mystery is responsible for this classpath problem.

[Terry-Weymouth]

I can reproduce this error in the environment described. Investigating in the interest of understanding the bug. Ouch. Color me embarrassed. Apparently, Eclipse or possible fat fingered typing generated a file name "javax.usb.properties " - note space at the end of the name. I would have spent hours looking for this but for the fact that I had copied the (copy/paste file in Eclipse into 4 locations) but failed to fine it with the unix command:
find . -name "javax.usb.properties"
I've retained/included this note so that others my consider checking for this error!

[luli12311]

you can put javax.usb.properties into your jkd source: jdk/jre/lib