Develop Reference

Trying to run libGDX with Maven and Eclipse

Maybe a newbie question...
I've been working on a LWJGL project, where I use Maven to manage dependencies. In it, I want to use some parts of the libgdx library. So I figured I will first run at least a helloworld working with it before I add it to my main project.
So in my pom.xml I have this:
<!-- https://mvnrepository.com/artifact/com.badlogicgames.gdx/gdx-backend-lwjgl -->
<dependency>
<groupId>com.badlogicgames.gdx</groupId>
<artifactId>gdx-backend-lwjgl</artifactId>
<version>1.9.11</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.badlogicgames.gdx/gdx-platform -->
<dependency>
<groupId>com.badlogicgames.gdx</groupId>
<artifactId>gdx-platform</artifactId>
<version>1.9.11</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.badlogicgames.gdx/gdx -->
<dependency>
<groupId>com.badlogicgames.gdx</groupId>
<artifactId>gdx</artifactId>
<version>1.9.11</version>
</dependency>
The other contents of the file are the same as in a working project and are 100% working.
I tried creating a separate libgdx project before that and... it didn't work. But, I saw that the code that was supposed to run the program was:
public static void main (String[] arg) {
LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
new LwjglApplication(new SomeApplicationListenerFile(), config);
}
So I used that in my maven project.
When I do "run as a Java Application", the error is the following:
Exception in thread "main" java.lang.NoClassDefFoundError: com/badlogic/gdx/backends/lwjgl/LwjglApplicationConfiguration
at org.boby.RayTracing.main.Main.main(Main.java:179)
And if I do a Maven Build, it tells me that "package com.badlogic.gdx.backends.lwjgl does not exist"
I looked for that package in the jars Maven downloaded in the "Maven dependencies" folder and I found it in gdx-backend-lwjgl-1.9.11.jar - right where it should be.
The package is apparently there, but Java cannot find it. How can I fix that?
Some additional information:
Windows 10, eclipse oxygen, Maven 3.6.0, JRE 1.8.0_191, JDK 8
Thank you in advance! I've been banging my head on this for hours.
Edit: I made some progress. Looks like the "test" was messing things up so I removed those statements. Now I get the following Error:
Exception in thread "main" com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load shared library 'gdx64.dll' for target: Windows 10, 64-bit
at com.badlogic.gdx.utils.SharedLibraryLoader.load(SharedLibraryLoader.java:125)
at com.badlogic.gdx.utils.GdxNativesLoader.load(GdxNativesLoader.java:33)
at com.badlogic.gdx.backends.lwjgl.LwjglNativesLoader.load(LwjglNativesLoader.java:47)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.<init>(LwjglApplication.java:83)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.<init>(LwjglApplication.java:71)
at org.boby.RayTracing.main.Main.main(Main.java:178)
It looks like I need to include gdx-natives.jar in my dependencies, but I can't find a maven repository for it.

I downloaded gdx-natives.jar (saw it in a forum thread). In there, was a file named "gdx-64.dll". As I need "gdx64.dll", I just renamed the dll and now it runs.

You can let Maven do the work if you define the gdx-platform dep like this:
<dependency>
<groupId>com.badlogicgames.gdx</groupId>
<artifactId>gdx-platform</artifactId>
<version>1.9.11</version>
<classifier>natives-desktop</classifier>
</dependency>
This will load the natives jar including the gdx64.dll so you don't have to add any external jar to your project in the build path.
A side note is: if you use the standard Maven repo directory structure and you load assets with the Gdx.files.internal("fileName") statement you need to define a folder in the main/repository with the same name as the package you have your code in. (i.e. main/java/myPackage relates to /main/repository/myPackage). I struggled a bit with this because I don't normaly have to define a package folder int the repository dir.

How to fix the "the-default-package-is-not-permitted-by-the-import-package-syntax" error while using geojson library?

I was upgrading to new library of geojson from version 14.2 to 20.2. And I was keep of getting below maven build error which is failing at the bundle processing with the message "the-default-package . -is-not-permitted-by-the-import-package-syntax".
I expect the maven build with bundle processing to be successful but the actual output is "the-default-package-is-not-permitted-by-the-import-package-syntax" error.

While upgrading the geotools library from old version 14.2 to new version 20.2, there were lot of changes has been made.
GeoTools Upgrade
This was one of the link that would help everyone to do it very easily. But with the upgradation of geotools, we also update the gt-geojson library too. This library contains the class "Skunkwork" without any package name which result in above error during bundle processing of maven build. To avoid this error,i have to remove this class. And it works fine.
Before Fix
POM Configuration:
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-geojson</artifactId>
<version>20.2</version>
</dependency>
After Fix
POM Configuration:
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-geojson</artifactId>
<version>20.2-fixed</version>
</dependency>
Note: This jar needs to be manually installed to your local repository. And as well as you need to install the fixed jar to remote artifactory if used by your code base such as Nexus, JFrog etc.

AndroidDriver giving ClassNotFoundException

I am still trying to get the example in this tutorial to work:
http://www.automationtestinghub.com/first-appium-test-script/
I am getting a ClassNotFoundException in the line:
AppiumDriver<MobileElement> driver = new AndroidDriver<MobileElement>(caps);
I have added java-client-6.0.0-BETA2.jar to my Build Path.
What am I missing?
This is not in any way connected to the question: How to resolve 'the import io cannot be resolved' - that part has been resolved.
Update 03/01/2018
I have converted my project to a Maven project.
Then I added the following to the pom.xml:
<!-- https://mvnrepository.com/artifact/io.appium/java-client -->
<dependency>
<groupId>io.appium</groupId>
<artifactId>java-client</artifactId>
<version>6.0.0-BETA2</version>
</dependency>
Then I ran Maven Build with Verify Clean.
The result was still the same:
ClassNotFoundException
Update 04/01/2018
Finally got this working.
I got a response from Appium support - “Selenium requires guava library to be in classpath.”
First I added the android version - but that gave a different error.
When I added the regular version - it all worked:
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>23.6-jre</version>
<!-- or, for Android: -->
<version>23.6-android</version>
</dependency>

My advice would be to add maven framework support to your project.
If using IntelliJ do the following:
Right Click your folder structure and hit Add Framework Support
Then tick the Maven box and click OK to add this as a Maven Project.
You should then have a pom.xml generated within your folder structure open this.
Within this pom.xml you need to add the following code:
https://gist.github.com/michaelvoase/54f3bbf47b888bb004330a1d1b108068
This will then import the Appium library into your project.

Maven build - force the use of a newer version

I am trying to build protege-server (https://github.com/protegeproject/org.protege.owl.server) from source. I downloaded the source code. Using "mvm -X package" yields the following error:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.
0:compile (default-compile) on project org.protege.owl.server: Compilation failu
re
[ERROR] /c:/Users/user/Programs/webprotege/org.protege.owl.server-master/src/mai
n/java/org/protege/owl/server/connect/local/OSGiLocalTransport.java:[11,32] type
org.osgi.framework.ServiceRegistration does not take parameters
Based on a previous question, an OSGI blogpost explains that the problem was fixed in a later (4.3.1) version of the library.
I tried to refer a newer version of this library in the POM.xml file:
<dependency>
<groupId>org.osgi</groupId>
<artifactId>core</artifactId>
<version>6.0.0</version>
<scope>system</scope>
<systemPath>/c:/Users/user/Downloads/osgi.core-6.0.0.jar</systemPath>
</dependency>
and even downloaded the newer version to specifically target it.
The error still occurs. Is there any way to solve it?
EDIT:
Attempting the solution suggested by #Balazs Zsoldos didn't help and I received the same error message. I noted an import of this package (org.osgi.framework) referring version 1:
<Bundle-Activator>org.protege.owl.server.Activator</Bundle-Activator>
<Bundle-SymbolicName>org.protege.owl.server</Bundle-SymbolicName>
<Bundle-Vendor>The Protege Development Team</Bundle-Vendor>
<Embed-Dependency>antlr, antlr-runtime, stringtemplate</Embed-Dependency>
<Export-Package>org.protege.owl.server*;version=2.0.6-SNAPSHOT</Export-Package>
<Import-Package>!org.antlr.stringtemplate,
!org.apache.commons.cli,
org.osgi.framework;version="1",
*</Import-Package>
An attempt to remove this line did not help either, as it appears in another dependency down stream. I could not find out how to override the downstream import-package instruction.
The effective pom.xml, as generated by eclipse, is attached as a link: https://docs.google.com/document/d/1eHFalUHVZ45ejLes_eqaXLw6ttjcTryphbGr_CKbhRk/edit?usp=sharing

The issue is that older versions of osgi.core are still on the classpath of the as they are imported with different group and artifact ids. Drag and drop the pom.xml to your eclipse and see the Dependency Hierarchy tab of the pom editor to get more information.
The following two are imported by dependencies:
org.osgi:org.osgi.core (by org.apache.felix.log)
org.apache.felix:org.osgi.core (by owlapi distribution)
To solve the problem, you should add the following dependency:
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi.core</artifactId>
<version>6.0.0</version>
<scope>provided</scope>
</dependency>
And as this does not override the org.apache.felix:org.osgi.core dependency, exclude that one:
<dependency>
<groupId>net.sourceforge.owlapi</groupId>
<artifactId>owlapi-distribution</artifactId>
<version>3.4.5</version>
<exclusions>
<exclusion>
<groupId>org.apache.felix</groupId>
<artifactId>org.osgi.core</artifactId>
</exclusion>
</exclusions>
</dependency>
(and remove the dependency with system scope as you do not need it and its artifactId is different from the standard anyway).
Edit
Just realized that the old osgi.core package is also inside org.apache.felix:org.apache.felix.framework that is pulled transitively by ProtegeLauncher via org.apache.felix:org.apache.felix.main:4.0.3. This means that you should either
Increment the version of org.apache.felix:org.apache.felix.main to the newest (or to one that at least implements osgi 4.3). In this case you do not need osgi.core at all
exclude org.apache.felix:org.apache.felix.main from edu.stanford.protege:ProtegeLauncher (and keep version 4.3.1 or higher of osgi.core)
I tried the second one and another issue comes that surfire plugin cannot be downloaded from maven central (or something similar, you will see).
Notes
The developer of this protege library was clearly not familiar how maven dependency management works and what should have been imported as a dependency. The project imports an OSGi runtime environment transitively that should never happen. For compilation only API should be imported and if the target runtime surely contains that API, it should be imported with provided scope. I would recommend to
not use this library or
clean it out (at least the maven dependency part) and send a pull request so the library can have an acceptable quality

java.lang.NoSuchFieldError: org.apache.http.message.BasicLineFormatter.INSTANCE from Mashape Unirest in Java application

I have a Maven Java project that uses Mashape Unirest for sending HTTP requests to other URLs. I am currently writing an integration test (using TestNG) that sends a normal HTTP request using Unirest. When I run the integration test through Maven (via the Failsafe plugin), the request is sent out successfully. However, when I try to run the integration test via Eclipse, I keep on getting the following error:
FAILED: getCurrentTimeTest
java.lang.NoSuchFieldError: INSTANCE
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:52)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:56)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<clinit>(DefaultHttpRequestWriterFactory.java:46)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:72)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:84)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<clinit>(ManagedHttpClientConnectionFactory.java:59)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager$InternalConnectionFactory.<init>(PoolingHttpClientConnectionManager.java:487)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:147)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:136)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:112)
at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:726)
at com.mashape.unirest.http.options.Options.refresh(Options.java:41)
at com.mashape.unirest.http.options.Options.<clinit>(Options.java:27)
at com.mashape.unirest.http.HttpClientHelper.prepareRequest(HttpClientHelper.java:141)
at com.mashape.unirest.http.HttpClientHelper.requestAsync(HttpClientHelper.java:80)
at com.mashape.unirest.request.BaseRequest.asStringAsync(BaseRequest.java:56)
at ...
I am also able to reproduce this error using a basic Java application script.
I have made sure that the dependencies I am using in my pom.xml file are the latest and greatest, as seen below:
<dependency>
<groupId>com.mashape.unirest</groupId>
<artifactId>unirest-java</artifactId>
<version>1.3.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.0</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.3.2</version>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20140107</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.3.2</version>
</dependency>
I have also checked out the source code of BasicLineFormatter.java, both from the source file downloaded to Eclipse and from Apache's Httpcore Github repo. In the Github repo, notice how the INSTANCE field is defined for the 4.3.x branch and the trunk branch, but not in older branches like 4.2.x. However, I am indeed using version 4.3.2 in my project, so I should be using a JAR file for Httpcore that has the latest version of BasicLineFormatter. I know that, based on the Maven Dependencies JAR files that are in my project, that I am indeed using the latest versions of these Apache dependencies, not the older versions specified as downstream dependencies of my project.
I have checked other various SOF and blog posts about this issue, such as Mashape Unirest Java : java.lang.NoClassDefFoundError and this blog post too, but they all seem to be talking about solving the NoSuchFieldError problem for Android. However, I'm dealing with a standalone Java application, not an Android application.
I am at a loss in determining how to troubleshoot this issue. Anyone have any idea what I need to do?
UPDATE
Instead of showing my test case, I will reduce the illustration of a reproduction of this problem to just a simple one-liner Java application, because the problem exists with any Java application or test case run through Eclipse, not just one particular test:
System.out.println(Unirest.get("http://www.google.com").asStringAsync().get().getBody());
Normally, this should print the HTML of the Google home page, but I instead get the NoSuchFieldError stack trace.
FIXED!
The problem was that the AWS SDK (it's on my classpath because I'm developing for Elastic Beanstalk) had a conflicting JAR file. Using Oleg's solution (thanks BTW), I printed the following output in a unit test:
jar:file:/some/path/aws-java-sdk/1.7.1/third-party/httpcomponents-client-4.2.3/httpcore-4.2.jar!/org/apache/http/message/BasicLineFormatter.class
I'll have to rearrange my classpath so that AWS SDK is no longer conflicting.

The only plausible explanation to this problem is there is an older version of HttpCore on the classpath (unless you also want to consider a possibility of green men from Mars messing with your computer remotely from a flying saucer).
You can add this snippet to your code to find out what jar the class gets picked up from. This might help find out why that jar is on your classpath in the first place.
ClassLoader classLoader = MyClass.class.getClassLoader();
URL resource = classLoader.getResource("org/apache/http/message/BasicLineFormatter.class");
System.out.println(resource);
This basically tells me that in my case the jar resides in the local maven repository and likely to have been added to the classpath by Maven
jar:file:/home/oleg/.m2/repository/org/apache/httpcomponents/httpcore/4.3.1/httpcore-4.3.1.jar!/org/apache/http/message/BasicLineFormatter.class

As already mentioned by previous comments, It's mainly because of the conflicting versions of httpcore jar, the static field INSTANCE is been added to BasicLineFormatter class in versions > 4.3.1, Though you might have added the latest version of the httpcore jar in your dependencies, but its highly possible that other (lower) version of jar is getting picked up.
So, first to confirm that, wrong jar is getting picked up, Use the following line of code -
ClassLoader classLoader = <Your Class>.class.getClassLoader();
URL resource = classLoader.getResource("org/apache/http/message/BasicLineFormatter.class");
System.out.println(resource);
If this prints, the lower version of the jar, then it's confirmed that it's picking the lower version of the httpcore jar (May be from other dependencies of your project),
Solution -
Add following maven/gradle dependencies at the top of dependency list (Or above the other project dependency which caused the conflict) -
<dependency>
<groupId>com.mashape.unirest</groupId>
<artifactId>unirest-java</artifactId>
<version>1.4.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.4.1</version>
</dependency>

I faced the same exception using unirest:
java.lang.NoSuchFieldError: INSTANCE
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:52)
at com.mashape.unirest.http.options.Options.refresh(Options.java:55)
at com.mashape.unirest.http.options.Options.<clinit>(Options.java:36)
And found it was due to DefaultConnectionKeepAliveStrategy.INSTANCE; and the conflicting jar was apache-httpcomponents-httpclient.jar in my classpath. Adding this post to help anyone who faces similar exception

I got this Exception: Caused by: java.lang.NoSuchFieldError: INSTANCE
Solution:
This happens if you have two different version classes in your classpath…. […], So I first find that class (one version of class), click that class, select build path, then I click remove from build path.

if you are using aws sdk this error occurs because of dependency mismatch.
To avoid this error do the following:
1.Put the dependecies in the required order aws sdk and the end preferably
2.Add shade plugin to the project
This solved my problem

you can refer to my answer in
HTTPClient Example - Exception in thread "main" java.lang.NoSuchFieldError: INSTANCE
my case is i have httpclient-4.4.1.jar, and httpcore-4.4.1.jar in my class path, but JVM loaded BasicLineFormatter from httpcore-4.0.jar