Javafx NullPointerException when Playing Sounds [duplicate] - java

This question already has an answer here:
How do I determine the correct path for FXML files, CSS files, Images, and other resources needed by my JavaFX Application?
(1 answer)
Closed 2 years ago.
I am working on a Javafx game and have been attempting to implement some sound using the following code:
URL laserResource = getClass().getResource("LaserBlast.wav");
AudioClip laserPlayer = new AudioClip(laserResource.toString());
This code is instantiated in the main class before any methods. I have a module called JavaFxImages which contains all my resources including my sounds and I have been successfully able to access images for ImageView from the folder through code such as Image asteroid = new Image("Asteroid.png");.
However, when I run my game I get a NullPointerException at the line for my audio clip. I have spent the past many hours researching and trying every different way to access this resource. I've tried many permutations of the URL ("JavaFxImages/LaserBlast.wav", Desktop/JavaFxImages/LaserBlast.wav", etc.), but every time it has the same error. I'm really at a loss for what is wrong with the code. I would greatly appreciate any help that can be given.
Thanks in advance!
The full error message is given below.
Error Message:
Exception in Application constructor
Exception in thread "main" java.lang.RuntimeException: Unable to construct Application instance: class sample.Main
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:907)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$156(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:819)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Caused by: java.lang.NullPointerException
at sample.Main.<init>(Main.java:76)
... 10 more


Your error mostly happens on Itellij IDEA - Javafx Project
Instead of:
URL laserResource = getClass().getResource("LaserBlast.wav");
AudioClip laserPlayer = new AudioClip(laserResource.toString());
Use:
//By default your Package_NAME is: sample
File laserResource = new File("src/Package_NAME/LaserBlast.wav");
AudioClip laserPlayer = new AudioClip(laserResource.toURI().toString());

Related

How to connect to Google big query with spark using java locally?

I am trying to connect to Google big query using spark in java, but I am unable to find accurate documentation for the same.
I tried: https://cloud.google.com/dataproc/docs/tutorials/bigquery-connector-spark-example
and
https://github.com/GoogleCloudPlatform/spark-bigquery-connector#compiling-against-the-connector
My code:
sparkSession.conf().set("credentialsFile", "/path/OfMyProjectJson.json");
Dataset<Row> dataset = sparkSession.read().format("bigquery").option("table","myProject.myBigQueryDb.myBigQuweryTable")
.load();
dataset.printSchema();
But this is throwing exception:
Exception in thread "main" java.util.ServiceConfigurationError: org.apache.spark.sql.sources.DataSourceRegister: Provider com.google.cloud.spark.bigquery.BigQueryRelationProvider could not be instantiated
at java.util.ServiceLoader.fail(ServiceLoader.java:232)
at java.util.ServiceLoader.access$100(ServiceLoader.java:185)
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:384)
at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
at scala.collection.convert.Wrappers$JIteratorWrapper.next(Wrappers.scala:43)
at scala.collection.Iterator$class.foreach(Iterator.scala:891)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
at scala.collection.TraversableLike$class.filterImpl(TraversableLike.scala:247)
at scala.collection.TraversableLike$class.filter(TraversableLike.scala:259)
at scala.collection.AbstractTraversable.filter(Traversable.scala:104)
at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:614)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:190)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:164)
at com.mySparkConnector.getDataset(BigQueryFetchClass.java:12)
Caused by: java.lang.IllegalArgumentException: A project ID is required for this service but could not be determined from the builder or the environment. Please set a project ID using the builder.
at com.google.cloud.spark.bigquery.repackaged.com.google.common.base.Preconditions.checkArgument(Preconditions.java:142)
at com.google.cloud.spark.bigquery.repackaged.com.google.cloud.ServiceOptions.<init>(ServiceOptions.java:285)
at com.google.cloud.spark.bigquery.repackaged.com.google.cloud.bigquery.BigQueryOptions.<init>(BigQueryOptions.java:91)
at com.google.cloud.spark.bigquery.repackaged.com.google.cloud.bigquery.BigQueryOptions.<init>(BigQueryOptions.java:30)
at com.google.cloud.spark.bigquery.repackaged.com.google.cloud.bigquery.BigQueryOptions$Builder.build(BigQueryOptions.java:86)
at com.google.cloud.spark.bigquery.repackaged.com.google.cloud.bigquery.BigQueryOptions.getDefaultInstance(BigQueryOptions.java:159)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider$.$lessinit$greater$default$2(BigQueryRelationProvider.scala:29)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider.<init>(BigQueryRelationProvider.scala:40)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380)
... 15 more
My json file contains project_id
I tried searching for possible solutions but am unable to find any, hence please help me with finding a solution to this exception, or else any documentation on how to connect to big query with spark.

I've got exactly the same error with DataProcPySparkOperator operator in the Airflow. The fix was to provide
dataproc_pyspark_jars='gs://spark-lib/bigquery/spark-bigquery-latest_2.12.jar'
instead of
dataproc_pyspark_jars='gs://spark-lib/bigquery/spark-bigquery-latest.jar'
I guess in your case it should be passed as a command line argument like
--jars=gs://spark-lib/bigquery/spark-bigquery-latest_2.12.jar

Recently a PR handling this issue has been merged to the the spark-bigquery-connector, a new version of the connector will be released soon.
A simple solution for now is to add the environment variable GOOGLE_APPLICATION_CREDENTIALS=/path/OfMyProjectJson.json to the spark runtime.

Spark 1.6 java.io.IOException: Filesystem closed

I have a strange issue. I'm not closing file system by .close() or .abort().
Locally my application is working perfectly, but when I try to do spark-submit on cluster I have got a lot of Exceptions
> ERROR scheduler.LiveListenerBus: Listener EventLoggingListener threw an exception
java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.spark.scheduler.EventLoggingListener$$anonfun$logEvent$3.apply(EventLoggingListener.scala:150)
at org.apache.spark.scheduler.EventLoggingListener$$anonfun$logEvent$3.apply(EventLoggingListener.scala:150)
at scala.Option.foreach(Option.scala:236)
at org.apache.spark.scheduler.EventLoggingListener.logEvent(EventLoggingListener.scala:150)
at org.apache.spark.scheduler.EventLoggingListener.onApplicationEnd(EventLoggingListener.scala:196)
at org.apache.spark.scheduler.SparkListenerBus$class.onPostEvent(SparkListenerBus.scala:54)
at org.apache.spark.scheduler.LiveListenerBus.onPostEvent(LiveListenerBus.scala:31)
at org.apache.spark.scheduler.LiveListenerBus.onPostEvent(LiveListenerBus.scala:31)
at org.apache.spark.util.ListenerBus$class.postToAll(ListenerBus.scala:55)
at org.apache.spark.util.AsynchronousListenerBus.postToAll(AsynchronousListenerBus.scala:38)
at org.apache.spark.util.AsynchronousListenerBus$$anon$1$$anonfun$run$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(AsynchronousListenerBus.scala:87)
at org.apache.spark.util.AsynchronousListenerBus$$anon$1$$anonfun$run$1$$anonfun$apply$mcV$sp$1.apply(AsynchronousListenerBus.scala:72)
at org.apache.spark.util.AsynchronousListenerBus$$anon$1$$anonfun$run$1$$anonfun$apply$mcV$sp$1.apply(AsynchronousListenerBus.scala:72)
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
at org.apache.spark.util.AsynchronousListenerBus$$anon$1$$anonfun$run$1.apply$mcV$sp(AsynchronousListenerBus.scala:71)
at org.apache.spark.util.Utils$.tryOrStopSparkContext(Utils.scala:1182)
at org.apache.spark.util.AsynchronousListenerBus$$anon$1.run(AsynchronousListenerBus.scala:70)
Caused by: java.io.IOException: Filesystem closed
at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:858)
at org.apache.hadoop.hdfs.DFSOutputStream.flushOrSync(DFSOutputStream.java:2350)
at org.apache.hadoop.hdfs.DFSOutputStream.hflush(DFSOutputStream.java:2296)
at org.apache.hadoop.fs.FSDataOutputStream.hflush(FSDataOutputStream.java:130)
... 20 more
But application is still running, until I have got. This error kills my app.
> ERROR util.Utils: Uncaught exception in thread Thread-3
java.io.IOException: Filesystem closed
at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:858)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2120)
at org.apache.hadoop.hdfs.DistributedFileSystem$20.doCall(DistributedFileSystem.java:1253)
at org.apache.hadoop.hdfs.DistributedFileSystem$20.doCall(DistributedFileSystem.java:1249)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1249)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1417)
at org.apache.spark.scheduler.EventLoggingListener.stop(EventLoggingListener.scala:224)
at org.apache.spark.SparkContext$$anonfun$stop$8$$anonfun$apply$mcV$sp$5.apply(SparkContext.scala:1744)
at org.apache.spark.SparkContext$$anonfun$stop$8$$anonfun$apply$mcV$sp$5.apply(SparkContext.scala:1744)
at scala.Option.foreach(Option.scala:236)
at org.apache.spark.SparkContext$$anonfun$stop$8.apply$mcV$sp(SparkContext.scala:1744)
at org.apache.spark.util.Utils$.tryLogNonFatalError(Utils.scala:1220)
at org.apache.spark.SparkContext.stop(SparkContext.scala:1743)
at org.apache.spark.SparkContext$$anonfun$3.apply$mcV$sp(SparkContext.scala:604)
at org.apache.spark.util.SparkShutdownHook.run(ShutdownHookManager.scala:267)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(ShutdownHookManager.scala:239)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1$$anonfun$apply$mcV$sp$1.apply(ShutdownHookManager.scala:239)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1$$anonfun$apply$mcV$sp$1.apply(ShutdownHookManager.scala:239)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1818)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1.apply$mcV$sp(ShutdownHookManager.scala:239)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1.apply(ShutdownHookManager.scala:239)
at org.apache.spark.util.SparkShutdownHookManager$$anonfun$runAll$1.apply(ShutdownHookManager.scala:239)
at scala.util.Try$.apply(Try.scala:161)
at org.apache.spark.util.SparkShutdownHookManager.runAll(ShutdownHookManager.scala:239)
at org.apache.spark.util.SparkShutdownHookManager$$anon$2.run(ShutdownHookManager.scala:218)
at org.apache.hadoop.util.ShutdownHookManager$1.run(ShutdownHookManager.java:54)
The last error is totally randomly, but it occurs 90% times when I'm using my app. Can be there be some with cluster configuration or my code is wrong?
Thanks

If the FileSystem is closed somewhere , the error will also occur when you use it again.

ServletUnit RequestDispatcher forward() / include() methods AbstractMethodError

I'm doing a java web app with a servlet and I wanted to write some tests to check its functionality (ex. authorization form). I hadn't been using any framework, just bare java in eclipse with tomcat 7.0
I've run into an error while trying to test authorization input. The app would check the login-password pair and then redirect using RequestDispatcher.forward() or RequestDispatcher.include() methods. But when executing them it throws an error with the following stack trace:
java.lang.reflect.Inv­ocationTargetExceptio­n
at su­n.reflect.NativeMetho­dAccessorImpl.invoke0­(Native Method)
at su­n.reflect.NativeMetho­dAccessorImpl.invoke(­Unknown Source)
at su­n.reflect.DelegatingM­ethodAccessorImpl.inv­oke(Unknown Source)
at ja­va.lang.reflect.Metho­d.invoke(Unknown Sour­ce)
at en­tryPoint.Dispatcher.d­ispatch(Dispatcher.ja­va:166)
at en­tryPoint.Dispatcher.s­ervice(Dispatcher.jav­a:49)
at ja­vax.servlet.http.Http­Servlet.service(HttpS­ervlet.java:728)
at co­m.meterware.servletun­it.InvocationContextI­mpl.service(Invocatio­nContextImpl.java:76)
at co­m.meterware.servletun­it.ServletUnitClient.­newResponse(ServletUn­itClient.java:126)
at co­m.meterware.httpunit.­WebClient.createRespo­nse(WebClient.java:64­7)
at co­m.meterware.httpunit.­WebWindow.getResource­(WebWindow.java:220)
at co­m.meterware.httpunit.­WebWindow.getSubframe­Response(WebWindow.ja­va:181)
at co­m.meterware.httpunit.­WebWindow.getResponse­(WebWindow.java:158)
at co­m.meterware.httpunit.­WebWindow.updateWindo­w(WebWindow.java:199)
at co­m.meterware.httpunit.­WebWindow.getSubframe­Response(WebWindow.ja­va:183)
at co­m.meterware.httpunit.­WebWindow.getResponse­(WebWindow.java:158)
at co­m.meterware.httpunit.­WebClient.getResponse­(WebClient.java:122)
at te­st.Authorization.test­AuthCorrectInput_Wron­gPassword(Authorizati­on.java:102)
at su­n.reflect.NativeMetho­dAccessorImpl.invoke0­(Native Method)
at su­n.reflect.NativeMetho­dAccessorImpl.invoke(­Unknown Source)
at su­n.reflect.DelegatingM­ethodAccessorImpl.inv­oke(Unknown Source)
at ja­va.lang.reflect.Metho­d.invoke(Unknown Sour­ce)
at or­g.junit.runners.model­.FrameworkMethod$1.ru­nReflectiveCall(Frame­workMethod.java:45)
at or­g.junit.internal.runn­ers.model.ReflectiveC­allable.run(Reflectiv­eCallable.java:15)
at or­g.junit.runners.model­.FrameworkMethod.invo­keExplosively(Framewo­rkMethod.java:42)
at or­g.junit.internal.runn­ers.statements.Invoke­Method.evaluate(Invok­eMethod.java:20)
at or­g.junit.internal.runn­ers.statements.RunBef­ores.evaluate(RunBefo­res.java:28)
at or­g.junit.runners.Paren­tRunner.runLeaf(Paren­tRunner.java:263)
at or­g.junit.runners.Block­JUnit4ClassRunner.run­Child(BlockJUnit4Clas­sRunner.java:68)
at or­g.junit.runners.Block­JUnit4ClassRunner.run­Child(BlockJUnit4Clas­sRunner.java:47)
at or­g.junit.runners.Paren­tRunner$3.run(ParentR­unner.java:231)
at or­g.junit.runners.Paren­tRunner$1.schedule(Pa­rentRunner.java:60)
at or­g.junit.runners.Paren­tRunner.runChildren(P­arentRunner.java:229)
at or­g.junit.runners.Paren­tRunner.access$000(Pa­rentRunner.java:50)
at or­g.junit.runners.Paren­tRunner$2.evaluate(Pa­rentRunner.java:222)
at or­g.junit.internal.runn­ers.statements.RunBef­ores.evaluate(RunBefo­res.java:28)
at or­g.junit.internal.runn­ers.statements.RunAft­ers.evaluate(RunAfter­s.java:30)
at or­g.junit.runners.Paren­tRunner.run(ParentRun­ner.java:300)
at or­g.eclipse.jdt.interna­l.junit4.runner.JUnit­4TestReference.run(JU­nit4TestReference.jav­a:50)
at or­g.eclipse.jdt.interna­l.junit.runner.TestEx­ecution.run(TestExecu­tion.java:38)
at or­g.eclipse.jdt.interna­l.junit.runner.Remote­TestRunner.runTests(R­emoteTestRunner.java:­467)
at or­g.eclipse.jdt.interna­l.junit.runner.Remote­TestRunner.runTests(R­emoteTestRunner.java:­683)
at or­g.eclipse.jdt.interna­l.junit.runner.Remote­TestRunner.run(Remote­TestRunner.java:390)
at or­g.eclipse.jdt.interna­l.junit.runner.Remote­TestRunner.main(Remot­eTestRunner.java:197)
Caused by: javax.serv­let.ServletException:­ java.lang.AbstractMe­thodError: com.meterw­are.servletunit.Servl­etUnitServletContext.­getClassLoader()Ljava­/lang/ClassLoader;
at or­g.apache.jasper.servl­et.JspServlet.service­(JspServlet.java:343)
at ja­vax.servlet.http.Http­Servlet.service(HttpS­ervlet.java:728)
at co­m.meterware.servletun­it.RequestDispatcherI­mpl.forward(RequestDi­spatcherImpl.java:54)
at co­ntrollers.Auth.index(­Auth.java:78)
... 4­4 more
Caused by: java.lang.­AbstractMethodError: ­com.meterware.servlet­unit.ServletUnitServl­etContext.getClassLoa­der()Ljava/lang/Class­Loader;
at or­g.apache.jasper.compi­ler.TagPluginManager.­init(TagPluginManager­.java:72)
at or­g.apache.jasper.compi­ler.TagPluginManager.­apply(TagPluginManage­r.java:56)
at or­g.apache.jasper.compi­ler.Compiler.generate­Java(Compiler.java:24­0)
at or­g.apache.jasper.compi­ler.Compiler.compile(­Compiler.java:373)
at or­g.apache.jasper.compi­ler.Compiler.compile(­Compiler.java:353)
at or­g.apache.jasper.compi­ler.Compiler.compile(­Compiler.java:340)
at or­g.apache.jasper.JspCo­mpilationContext.comp­ile(JspCompilationCon­text.java:646)
at or­g.apache.jasper.servl­et.JspServletWrapper.­service(JspServletWra­pper.java:357) ­
at or­g.apache.jasper.servl­et.JspServlet.service­JspFile(JspServlet.ja­va:390)
at or­g.apache.jasper.servl­et.JspServlet.service­(JspServlet.java:334)
... 4­7 more
The first block represents an invocation error caught by central controller (Dispatcher) servlet while invoking method in which an AbstractMethodError had been thrown. The second and third ones are about that error.
The code of the test method is as follows:
#Test
publi­c void testAuthIncorr­ectInput_Long() throw­s Exception {
W­ebRequest request = n­ew PostMethodWebReque­st("http://localhost:­8080/CenralReportDL/D­ispatcher?query=auth"­);
S­tring longString = ne­w String();
f­or (int i = 0; i < 52­; i++) {
­ longString­ += "aA_ba";
}
reque­st.setParameter("user­name", longString);
reque­st.setParameter("pass­word", longString);
W­ebResponse response =­ client.getResponse(r­equest);
a­ssertNotNull("No resp­onse received", respo­nse);
}
How can I get rid of this error? Is there a workaround? Should I maybe use some other means of servlet testing?
Also please do not suggest framework-specific testing utils such as strutstest, I want an actual solution for bare java web application.
UPDATE: In response to #JekinKalariya - I had a JasperException before. It complained about files not being in /WEB-INF folder, but due to my project structure they all were in /WebContent/WEB-INF. I was so frustrated because of that I just copied entire folder. Silly thing to do. I deleted it and now I'm back to that JasperException.
UPDATE: Now, I've done some research and found some answers on this issue. Didn't work for me though. I also found a suggestion to change a target runtime to J2EE Preview, which raised a different kind of exception:
com.meterware.httpuni­t.HttpNotFoundExcepti­on: Error on HTTP req­uest: 404 java.lang.C­lassNotFoundException­: org.apache.jasper.s­ervlet.JspServlet [http://localhost/WEB-­INF/jsp/auth.jsp]

StdDraw in Eclipse

So i need to draw some small .gif pictures with the help of StdDraw (it MUST be StdDraw), but im running into an really stupid error. My Code is:
while(true){
StdDraw.setXscale(-R,R);
StdDraw.setYscale(-R,R);
StdDraw.picture(0, 0, "starfield.jpg");
}
where R is a Double and starfield.jpg is the Background Picture.
The Error i get when trying to run this is:
Exception in thread "main" sun.misc.ServiceConfigurationError: javax.imageio.spi.ImageReaderSpi: Provider it.tidalwave.imageio.arw.ARWImageReaderSpi not found
at sun.misc.Service.fail(Service.java:129)
at sun.misc.Service.access$000(Service.java:111)
at sun.misc.Service$LazyIterator.next(Service.java:274)
at javax.imageio.spi.IIORegistry$1.run(IIORegistry.java:224)
at java.security.AccessController.doPrivileged(Native Method)
at javax.imageio.spi.IIORegistry.registerInstalledProviders(IIORegistry.java:232)
at javax.imageio.spi.IIORegistry.registerStandardSpis(IIORegistry.java:167)
at javax.imageio.spi.IIORegistry.<init>(IIORegistry.java:120)
at javax.imageio.spi.IIORegistry.getDefaultInstance(IIORegistry.java:142)
at apple.awt.CToolkit.registerDefaultServices(CToolkit.java:1346)
at apple.awt.CToolkit.<init>(CToolkit.java:154)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:357)
at java.lang.Class.newInstance(Class.java:310)
at java.awt.Toolkit$2.run(Toolkit.java:859)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:826)
at java.awt.Window.getToolkit(Window.java:1177)
at java.awt.Window.init(Window.java:397)
at java.awt.Window.<init>(Window.java:433)
at java.awt.Frame.<init>(Frame.java:403)
at java.awt.Frame.<init>(Frame.java:368)
at javax.swing.JFrame.<init>(JFrame.java:158)
at StdDraw.init(StdDraw.java:173)
at StdDraw.<clinit>(StdDraw.java:145)
at Sonnensystem.main(Sonnensystem.java:58)
And because of this beeng a really huge error, i could not find any solution via Google, and i cant find the error myself. So if anyone can point me in the righ direction, this would be great!
I added the stdlib.jar as External Archive as described in this Video: https://www.youtube.com/watch?v=taJovOCBPS4

Okay, found the solution, I needed to export my code as Runnable JAR, after that it worked as expected.

Sending a serialized Android object using sockets throws an InvalidClassException

I'm trying to make an online drawing game. For that I'm using the Path class in Android and I need to send it to my Java server. To do that, I had tried to extend the Path class, as follows:
public class SerializedPath extends Path implements Serializable {
private static final long serialVersionUID = -5974912367682897467L;
}
To simplify things and to narrow down the problem, all I did was to send it with outputStream.writeObject(new SerializedPath) and then outputStream.flush() where outputStream is an instance of ObjectOutputStream. Over the server I simply read it using inputStream.readObject() where inputStream is an instance of ObjectInputStream. The exception I'm getting is:
java.io.InvalidClassException: com.droplay.drawingonline.path.SerializedPath; unable to create instance
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at com.droplay.drawingonline.Session.run(Session.java:71)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedSerializationConstructorAccessor1.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.io.ObjectStreamClass.newInstance(Unknown Source)
... 5 more
Caused by: java.lang.RuntimeException: Stub!
at android.graphics.Path.(Path.java:24)
... 8 more
Now, to isolate the problem, I had tried creating a new class that doesn't have any members and doesn't extend anything and it did work. The server didn't throw any exception and it worked like a charm. I made sure the packages names are the same, the names of the classes are the same, the server uses the same SDK files as my Android project and the files' code in both the Android app and the Java server are EXACTLY the same, but I keep getting this exception. The app doesn't throw any exception. It sends the object just fine. Please, what's wrong with my code? Thank you for helping! :)

Well I managed to solve it by sending the position of each click to the server, instead of a path class. But why didn't it work when I serialized it?

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