[java] How do I fix a NoSuchMethodError?

I'm getting a NoSuchMethodError error when running my Java program. What's wrong and how do I fix it?

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.

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.

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

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/

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 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.

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

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.

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.

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.

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)]

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)

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.

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 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)

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.)

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.

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

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.

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.

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

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.

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.

If your file name is different than the class name which contain main method then it may be the possibility that this error may cause.

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.

1. Employee.java --> Contains the variable (EmpId) whose Data Type has been changed from int to String.
2. 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.

Just adding to existing answers. I was facing this issue with tomcat in eclipse. I had changed one class and did following steps,

1. Cleaned and built the project in eclpise

2. mvn clean install

3. 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

It means the respective method is not present in the class:

1. If you are using jar then decompile and check if the respective version of jar have proper class.
2. Check if you have compiled proper class from your source.

I ran into a similar problem when I was changing method signatures in my application. Cleaning and rebuilding my project resolved the "NoSuchMethodError".

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]

...

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.

1. If it happens in the run time, check the class containing the method is in class path.
2. Check if you have added new version of JAR and the method is compatible.