Websocket Client Could not find an implementation class - java

I will preface this with I am not using any maven dependencies, yet I know that I am missing a jar file wls-api.jar (at least that is what I have read).
To remedy this I downloaded the oracle-weblogic-7.9.jar but the problem persists.
The exception is thrown at this line
WebSocketContainer container = ContainerProvider.getWebSocketContainer();
Can anyone tell me why this line continuously fails?
UPDATE: upon further reading the examples I see use this dependency
<dependency>
<groupId>javax.websocket</groupId>
<artifactId>javax.websocket-api</artifactId>
<version>1.0</version>
I have javax.websocket-api.jar in the build path of the server and the client as it is required. What am I missing here?
Other update: I forgot to include the error thrown!
Exception in thread "main" java.lang.RuntimeException: Could not find an implementation class.
at javax.websocket.ContainerProvider.getWebSocketContainer(ContainerProvider.java:73)
at connect.<init>(connect.java:21)
at test.main(test.java:11)

javax.websocket api is only the specification don't have full implementation you may need to take the jar file tyrus-standalone-client-1.9.jar and try the same example that should solve your problem. i tested with my example and it is working fine.
hope this will help you.

I think the RuntimeException you are experiencing is fortunately not generated by any direct coding fault of your own.
The method getWebSocketContainer(), as described here, simply tries to load other classes and get the static instance of the ContainerProvider in the server.
The method looks for the ContainerProvider implementation class in the order listed in the META-INF/services/javax.websocket.ContainerProvider file, returning the WebSocketContainer implementation from the ContainerProvider implementation that is not null.
This, unfortunately, means that your project is not configured correctly. Double check to make sure this file is included in your project's build path.
If other projects you are looking at are using the Maven dependency you described, I would try to set up your project to do the same.
Hope this helped!

Adding
// https://mvnrepository.com/artifact/org.glassfish.tyrus.bundles/tyrus-standalone-client
compile group: 'org.glassfish.tyrus.bundles', name: 'tyrus-standalone-client', version: '1.9'
to my build.gradle file worked for me.

Related

Spring MVC application getting runtime exception after Spring framework upgrade to 5.2.20.Release [duplicate]

What are the possible causes for ABstractMethodError?
Exception in thread "pool-1-thread-1" java.lang.AbstractMethodError:
org.apache.thrift.ProcessFunction.isOneway()Z
at org.apache.thrift.ProcessFunction.process(ProcessFunction.java:51)
at org.apache.thrift.TBaseProcessor.process(TBaseProcessor.java:39)
at com.gemfire.gemstone.thrift.hbase.ThreadPoolServer$ClientConnnection.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
It usually means that you are using an old version of an interface implementation which is missing a new interface method. For example java.sql.Connection interface got a new getSchema method in 1.7. If you have 1.6 JDBC driver and call Connection.getSchema you will get AbstractMethodError.
The simple answer is this: some code is trying to call a method which is declared abstract. Abstract methods have no body and cannot be executed. Since you have provided so little information I can't really elaborate more on how this can happen since the compiler usually catches this problem - as described here, this means the class must have changed at runtime.
From documnentation of AbstractMethodError
Thrown when an application tries to call an abstract method. Normally,
this error is caught by the compiler; this error can only occur at run
time if the definition of some class has incompatibly changed since
the currently executing method was last compiled.
A kind of special case of the above answer.
I had this error, because I was using a spring-boot-starter-parent (e.g. 2.1.0.RELEASE uses spring version: 5.1.2.RELEASE) but I also included a BOM, that also defined some spring dependencies, but in an older version (e.g. 5.0.9.RELEASE).
So one thing to do, is check your dependency tree (in Eclipse e.g. you can use the Dependency Hierarchy) if you are using the same versions.
So one solution could be that you upgrade the spring dependencies in your BOM, another one could be that you exclude them (but depending on the amount, this could be ugly).
If you download any project zip file, after unzipping them and importing into Android Studio, you are unable to run the project because this error happened.
I got out of the problem by deleting my android studio, then download and install the new version.
I truly hope it help.
If you you are getting this error on the implemented methods, make sure you have added your dependencies correctly as mentioned in this thread.
As Damian quoted :
Normally, this error is caught by the compiler; this error can only
occur at run time if [...]
I had the same error that was not caught by the compiler but at runtime. To solve it I only compiled again without giving the code any modification.
if you are getting this error on a minified build using Proguard then check if the class is a POJO class and if so then exclude it from the Proguard using the below rule:
-keep class your.application.package.pojo.** {*;}
I had the same error when I imported an eclipse project into intellij ide.. I tried to import it without .iml file then my problem was solved
I get this problem when I update my kotlin plugin to a new version .... the problem is that my pom file is using the older kotlin version .. I guess it might help someone if he is doing this mistake
I am getting various of these and others infrequently on android.. I have to clean everything change som configuration rebuild change configuration again to normal somehow just the build tools don't rebuild everything they should for whatever reason (Android gradle bug obviously).

How to choose which library to use in a class (maven)?

I'm started working on an already existing project. In this project there is some JSON-parsing happening with the following exception being thrown by several methods:
JSONException.class
While I was unit-testing these parsers I couldn't import the right org.json.JSONException library.
The maven library used in the codebase was (package org.json.JSONException):
org.json:json:20160810
And the one that was importing in my tests was (package org.json.JSONException):
com.vaadin.external.google:android-json:0.0.20131108.vaadin1
I think the problem lies in both libraries share the same package names. When the test is execute the JSONException is thrown but the test still fails because its probably the other library. Anybody knows why this problem is happening and how to solve it?
Thanks in advance!
I believe you need to updated your pom.xml file and in the dependency section you can exclude a 3rd party dependency from a declared dependency. I guess in your case there is a dependency to json and vaadin, you'll find vaadin is also pulling the different version of json.
You can try removing one of them. As suggested here:
https://github.com/spring-cloud/spring-cloud-deployer-kubernetes/issues/142

PubsubIO.readStrings() throwing java.lang.NoSuchMethodError in Apache Beam v2.0.0 [duplicate]

I'm getting a NoSuchMethodError error when running my Java program. What's wrong and how do I fix it?
Without any more information it is difficult to pinpoint the problem, but the root cause is that you most likely have compiled a class against a different version of the class that is missing a method, than the one you are using when running it.
Look at the stack trace ... If the exception appears when calling a method on an object in a library, you are most likely using separate versions of the library when compiling and running. Make sure you have the right version both places.
If the exception appears when calling a method on objects instantiated by classes you made, then your build process seems to be faulty. Make sure the class files that you are actually running are updated when you compile.
I was having your problem, and this is how I fixed it. The following steps are a working way to add a library. I had done the first two steps right, but I hadn't done the last one by dragging the ".jar" file direct from the file system into the "lib" folder on my eclipse project. Additionally, I had to remove the previous version of the library from both the build path and the "lib" folder.
Step 1 - Add .jar to build path
Step 2 - Associate sources and javadocs (optional)
Step 3 - Actually drag .jar file into "lib" folder (not optional)
Note that in the case of reflection, you get an NoSuchMethodException, while with non-reflective code, you get NoSuchMethodError. I tend to go looking in very different places when confronted with one versus the other.
If you have access to change the JVM parameters, adding verbose output should allow you to see what classes are being loaded from which JAR files.
java -verbose:class <other args>
When your program is run, the JVM should dump to standard out information such as:
...
[Loaded junit.framework.Assert from file:/C:/Program%20Files/junit3.8.2/junit.jar]
...
If using Maven or another framework, and you get this error almost randomly, try a clean install like...
clean install
This is especially likely to work if you wrote the object and you know it has the method.
This is usually caused when using a build system like Apache Ant that only compiles java files when the java file is newer than the class file. If a method signature changes and classes were using the old version things may not be compiled correctly. The usual fix is to do a full rebuild (usually "ant clean" then "ant").
Sometimes this can also be caused when compiling against one version of a library but running against a different version.
I had the same error:
Exception in thread "main" java.lang.NoSuchMethodError: com.fasterxml.jackson.core.JsonGenerator.writeStartObject(Ljava/lang/Object;)V
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:151)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:292)
at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:3681)
at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3057)
To solve it I checked, firstly, Module Dependency Diagram (click in your POM the combination -> Ctrl+Alt+Shift+U or right click in your POM -> Maven -> Show dependencies) to understand where exactly was the conflict between libraries (Intelij IDEA). In my particular case, I had different versions of Jackson dependencies.
1) So, I added directly in my POM of the project explicitly the highest version - 2.8.7 of these two.
In properties:
<jackson.version>2.8.7</jackson.version>
And as dependency:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
2) But also it can be solved using Dependency Exclusions.
By the same principle as below in example:
<dependency>
<groupId>group-a</groupId>
<artifactId>artifact-a</artifactId>
<version>1.0</version>
<exclusions>
<exclusion>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</exclusion>
</exclusions>
</dependency>
Dependency with unwanted version will be excluded from your project.
This can also be the result of using reflection. If you have code that reflects on a class and extracts a method by name (eg: with Class.getDeclaredMethod("someMethodName", .....)) then any time that method name changes, such as during a refactor, you will need to remember to update the parameters to the reflection method to match the new method signature, or the getDeclaredMethod call will throw a NoSuchMethodException.
If this is the reason, then the stack trace should show the point that the reflection method is invoked, and you'll just need to update the parameters to match the actual method signature.
In my experience, this comes up occasionally when unit testing private methods/fields, and using a TestUtilities class to extract fields for test verification. (Generally with legacy code that wasn't designed with unit testing in mind.)
If you are writing a webapp, ensure that you don't have conflicting versions of a jar in your container's global library directory and also in your app. You may not necessarily know which jar is being used by the classloader.
e.g.
tomcat/common/lib
mywebapp/WEB-INF/lib
For me it happened because I changed argument type in function, from Object a, to String a. I could resolve it with clean and build again
In my case I had a multi module project and scenario was like com.xyz.TestClass was in module A and as well as in module B and module A was dependent on module B. So while creating a assembly jar I think only one version of class was retained if that doesn't have the invoked method then I was getting NoSuchMethodError runtime exception, but compilation was fine.
Related : https://reflectoring.io/nosuchmethod/
Why anybody doesn't mention dependency conflicts? This common problem can be related to included dependency jars with different versions.
Detailed explanation and solution: https://dzone.com/articles/solving-dependency-conflicts-in-maven
Short answer;
Add this maven dependency;
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-enforcer-plugin</artifactId>
<version>3.0.0-M3</version>
<configuration>
<rules>
<dependencyConvergence />
</rules>
</configuration>
</plugin>
Then run this command;
mvn enforcer:enforce
Maybe this is the cause your the issue you faced.
It means the respective method is not present in the class:
If you are using jar then decompile and check if the respective version of jar have proper class.
Check if you have compiled proper class from your source.
I have just solved this error by restarting my Eclipse and run the applcation.
The reason for my case may because I replace my source files without closing my project or Eclipse.
Which caused different version of classes I was using.
Try this way: remove all .class files under your project directories (and, of course, all subdirectories). Rebuild.
Sometimes mvn clean (if you are using maven) does not clean .class files manually created by javac. And those old files contain old signatures, leading to NoSuchMethodError.
Just adding to existing answers. I was facing this issue with tomcat in eclipse. I had changed one class and did following steps,
Cleaned and built the project in eclpise
mvn clean install
Restarted tomcat
Still I was facing same error. Then I cleaned tomcat, cleaned tomcat working directory and restarted server and my issue is gone. Hope this helps someone
These problems are caused by the use of the same object at the same two classes.
Objects used does not contain new method has been added that the new object class contains.
ex:
filenotnull=/DayMoreConfig.conf
16-07-2015 05:02:10:ussdgw-1: Open TCP/IP connection to SMSC: 10.149.96.66 at 2775
16-07-2015 05:02:10:ussdgw-1: Bind request: (bindreq: (pdu: 0 9 0 [1]) 900 900 GEN 52 (addrrang: 0 0 2000) )
Exception in thread "main" java.lang.NoSuchMethodError: gateway.smpp.PDUEventListener.<init>(Lgateway/smpp/USSDClient;)V
at gateway.smpp.USSDClient.bind(USSDClient.java:139)
at gateway.USSDGW.initSmppConnection(USSDGW.java:274)
at gateway.USSDGW.<init>(USSDGW.java:184)
at com.vinaphone.app.ttn.USSDDayMore.main(USSDDayMore.java:40)
-bash-3.00$
These problems are caused by the concomitant 02 similar class (1 in src, 1 in jar file here is gateway.jar)
To answer the original question. According to java docs here:
"NoSuchMethodError" Thrown if an application tries to call a specified method of a class (either static or instance), and that class no longer has a definition of that method.
Normally, this error is caught by the compiler; this error can only occur at run time if the definition of a class has incompatibly changed.
If it happens in the run time, check the class containing the method is in class path.
Check if you have added new version of JAR and the method is compatible.
I fixed this problem in Eclipse by renaming a Junit test file.
In my Eclipse work space I have an App project and a Test project.
The Test project has the App project as a required project on the build path.
Started getting the NoSuchMethodError.
Then I realized the class in the Test project had the same name as the class in the App project.
App/
src/
com.example/
Projection.java
Test/
src/
com.example/
Projection.java
After renaming the Test to the correct name "ProjectionTest.java" the exception went away.
NoSuchMethodError : I have spend couple of hours fixing this issue, finally fixed it by just renaming package name , clean and build ... Try clean build first if it doesn't works try renaming the class name or package name and clean build...it should be fixed. Good luck.
I ran into a similar problem when I was changing method signatures in my application.
Cleaning and rebuilding my project resolved the "NoSuchMethodError".
Above answer explains very well ..just to add one thing
If you are using using eclipse use ctrl+shift+T and enter package structure of class (e.g. : gateway.smpp.PDUEventListener ), you will find all jars/projects where it's present. Remove unnecessary jars from classpath or add above in class path. Now it will pick up correct one.
I ran into similar issue.
Caused by: java.lang.NoSuchMethodError: com.abc.Employee.getEmpId()I
Finally I identified the root cause was changing the data type of variable.
Employee.java --> Contains the variable (EmpId) whose Data Type has been changed from int to String.
ReportGeneration.java --> Retrieves the value using the getter, getEmpId().
We are supposed to rebundle the jar by including only the modified classes. As there was no change in ReportGeneration.java I was only including the Employee.class in Jar file. I had to include the ReportGeneration.class file in the jar to solve the issue.
I've had the same problem. This is also caused when there is an ambiguity in classes. My program was trying to invoke a method which was present in two JAR files present in the same location / class path. Delete one JAR file or execute your code such that only one JAR file is used. Check that you are not using same JAR or different versions of the same JAR that contain the same class.
DISP_E_EXCEPTION [step] [] [Z-JAVA-105 Java exception java.lang.NoSuchMethodError(com.example.yourmethod)]
Most of the times java.lang.NoSuchMethodError is caught be compiler but sometimes it can occur at runtime. If this error occurs at runtime then the only reason could be the change in the class structure that made it incompatible.
Best Explanation: https://www.journaldev.com/14538/java-lang-nosuchmethoderror
I've encountered this error too.
My problem was that I've changed a method's signature, something like
void invest(Currency money){...}
into
void invest(Euro money){...}
This method was invoked from a context similar to
public static void main(String args[]) {
Bank myBank = new Bank();
Euro capital = new Euro();
myBank.invest(capital);
}
The compiler was silent with regard to warnings/ errors, as capital is both Currency as well as Euro.
The problem appeared due to the fact that I only compiled the class in which the method was defined - Bank, but not the class from which the method is being called from, which contains the main() method.
This issue is not something you might encounter too often, as most frequently the project is rebuilt mannually or a Build action is triggered automatically, instead of just compiling the one modified class.
My usecase was that I generated a .jar file which was to be used as a hotfix, that did not contain the App.class as this was not modified. It made sense to me not to include it as I kept the initial argument's base class trough inheritance.
The thing is, when you compile a class, the resulting bytecode is kind of static, in other words, it's a hard-reference.
The original disassembled bytecode (generated with the javap tool) looks like this:
#7 = Methodref #2.#22 // Bank.invest:(LCurrency;)V
After the ClassLoader loads the new compiled Bank.class, it will not find such a method, it appears as if it was removed and not changed, thus the named error.
Hope this helps.
The problem in my case was having two versions of the same library in the build path. The older version of the library didn't have the function, and newer one did.
I had a similar problem with my Gradle Project using Intelij.
I solved it by deleting the .gradle (see screenshot below) Package and rebuilding the Project.
.gradle Package
I had faced the same issue. I changed the return type of one method and ran the test code of that one class. That is when I faced this NoSuchMethodError. As a solution, I ran the maven builds on the entire repository once, before running the test code again. The issue got resolved in the next single test run.
One such instance where this error occurs:
I happened to make a silly mistake of accessing private static member variables in a non static method. Changing the method to static solved the problem.

BodyEditorLoader.jar gives NoSuchMethodError

I was just starting to use the BodyEditorLoader.jar library but i got a NoSuchMethodError without any reason. Then i googled it and found a post on stackoverflow which wasn't useful and links were also broken but i came to know that the official library out there is buggy.
How do i fix this? Could not found the updated version of the library. Also some people provided the updated java file but how do i make it a library file as the library file contains the .class file and not the .java file.
Anyways here is the error:
java.lang.NoSuchMethodError: com.badlogic.gdx.utils.JsonReader.parse
and here is the code that gives the error:
BodyEditorLoader loader = new BodyEditorLoader(Gdx.files.internal("data/test.json"));
From question it's seems you have some buggy BodyEditorLoader class, you can inject gdx-utils jar inside your core module and after that you can access BodyEditorLoader class inside your project, May be it solve your problem.
dependencies {
compile group: 'com.github.itsabhiaryan', name: 'gdx-utils', version: '1.0.1-SNAPSHOT'
}
Don't forget to refresh all of your gradle module.

java / NoClassDefFoundError error at runtime only

I'm having trouble including a JAR file that adds a class that will let my main class send emails.
What I have done...
Saved the EmailAPI.jar file in my folder, as mentioned in below POM text (and it finds it, because in NetBeans I can explore the class)
Updated the dependency in my POM file, as follows:
<dependency>
<groupId>EmailAPI</groupId>
<artifactId>EmailAPI</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${basedir}\src\lib\EmailAPI.jar</systemPath>
</dependency>
Add the import (NetBeans automatically added this when I used the Email class, so it seems to know where to look...)
import me.nrubin29.emailapi.Email;
Call the class, directly using the structure provided
//send an email
new Email()
.withSMTPServer("smtp.gmail.com")
.withUsername("xxxxx#gmail.com")
.withPassword("xxxxxxx")
.withTo("xxxxx#gmail.com; xxxxx#gmail.com")
.withSubject("[RP] Server has started")
.withBody("This is the body!")
.send();
I can build fine, it all works out... but then when I try to run it (as a plugin to Minecraft), I get a NoClassDefFoundError, as shown here:
http://pastebin.com/V33gCLVG
I don't understand what I'm missing here. Can anyone point me in the right direction?
You use <scope>system</scope>. Is it available in the Minecraft enviroment? See Maven, Introduction to the Dependency Mechanism, Dependency Scope: "This scope is similar to provided [...] " and under provided: "indicates you expect [...] a container to provide the dependency at runtime."
It means that you are missing the jar in your runtime environment. You might need to change the scope of your maven dependency to compile.
EmailAPI requires two JARs in order to run. I think they are activation and mail or something. I can look at the project but I think you might be missing them.

Categories