No such method exception



How to Fix java.lang.NoSuchMethodError in Java

Table of Contents

A java.lang.NoSuchMethodError is a runtime error in Java which occurs when a method is called that exists at compile-time, but does not exist at runtime. The Java Garbage Collector (GC) cannot free up the space required for a new object, which causes a java.lang.OutOfMemoryError . This error can also be thrown when the native memory is insufficient to support the loading of a Java class.

What Causes java.lang.NoSuchMethodError

The java.lang.NoSuchMethodError occurs when an application does not find a called method at runtime. Some of the most common causes for a java.lang.NoSuchMethodError are:

Breaking change in an third party library

If an application calls a method in a third party library, which exists at compile time but not at runtime, it can cause a java.lang.NoSuchMethodError . The third party library may have introduced a breaking change from one version to another — for example, it may have removed the method being called.

This usually indicates a problem with the build, since the method does exist at compile time but not at runtime. The version of the library used in the build may be different from the one used in the application code.

Breaking change within an application

A change in the class structure within an application can also cause a java.lang.NoSuchMethodError . This can happen in a multi-module application where a method may have been removed from the code in one module, which was called by another module.

This also indicates a problem with the build process, which may be referring to a different version of the called module.

Overriding third party library version

This can happen in case a third party library is used in an application, but not directly. For example, it could be a dependency of other third party libraries in the application, but which use different versions of the called library.

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This can lead to a version conflict, resulting in a java.lang.NoSuchMethodError. Using build tools like Apache Maven and Gradle can prevent these kinds of version conflicts with their dependency management capabilities.

java.lang.NoSuchMethodError Example

Here is an example of java.lang.NoSuchMethodError thrown due to a breaking change introduced within an application.

Two classes will be created for this, the first of which is NoSuchMethodErrorExample which contains a method called print():

The second class Main calls the print() method from NoSuchMethodErrorExample :

When the Main class is executed, it produces the following output as expected:

Now if the print() method is removed from the NoSuchMethodErrorExample class and only this class is recompiled, when the Main class is executed again, it throws a java.lang.NoSuchMethodError :

The java.lang.NoSuchMethodError is thrown because the print() method is not found at runtime.

How to fix the java.lang.NoSuchMethodError

1. Full clean and compile

If a java.lang.NoSuchMethodError is encountered due to a breaking change within an application, a full clean and re-compilation of the project(s) containing both the calling and called classes should be performed. This will help make sure that the latest versions of the classes are used and resolve any inconsistencies.

2. Resolve third party library versioning issues

If a java.lang.NoSuchMethodError comes from calling a third party library method, finding out which library contains the called class and method can help detect inconsistent versioning between compile time and runtime dependencies.

The Java runtime option -verbose:class can be used to obtain information about the libraries used to load the called class. As an example, running the -verbose:class can produce the following output:

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Examining the output can help figure out the version of the libraries used at runtime and resolve any inconsistencies.

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no such method exception on getMethod

  • Could someone give me a hand please? I don’t understand why the code below is throwing a no such method exception. Any help would be greatly appreciated.
    Thanks
    apriest
    =================================================================
    import java.io.*;
    import java.util.*;
    import java.lang.reflect.*;
    public class testinvoke
    <
    public static void main(String args[])
    <
    invoke();
    >

    public static void invoke()
    <
    Object[] t = new Object[]<"1

    90″>;
    String mn = «hello»;
    try
    Method m = testinvoke.class.getMethod(mn, null);
    m.invoke(mn, t);
    >
    catch (Exception ex)
    <
    System.err.println(«no such method: » + mn);
    >
    >
    public void hello(Object args[])
    <
    for (int x=0; x

  • «I’m not back.» — Bill Harding, Twister

  • Thanks for the help Jim. Unfortunately, this did not fix the problem. I’m still getting the no such method exception. Could this be a problem under windows?

    Originally posted by Jim Yingst:
    The problem is here:

    The second parameter of getMethod shoudl be an array of Class objects representing the argument types of your method. By leaving it null, you are telling Java to look for a method named «hello» which takes no arguments. Obviously, there isn’t one. We want ask for a method which takes an array of objects as its sole argument. Try this:

  • «I’m not back.» — Bill Harding, Twister

  • This is the exception printed in the stack trace. It tells me that it could not find a pointer to the hello method or «no such method» isn’t it?

    java.lang.NullPointerException
    at java.lang.reflect.Method.invoke(Native Method)
    at testinvoke.invoke(testinvoke.java:21)
    at testinvoke.main(testinvoke.java:9)

    Originally posted by Jim Yingst:
    No, you are getting a different exception, but you are labeling it a NoSuchMethodException for some unknown reason. Replace

    with

    Never hide information from exceptions; it’s valuable. Read what the actual exception says carefully, read the API for the method you’re trying to use, and see if you can figure out what’s wrong.

  • «I’m not back.» — Bill Harding, Twister

  • OK. This is the new exception and below it is the code that generated it. I can’t figure out whether my problem is being too new to java or if there is really a bug here. An IllegalArgument Exception would indicate to me that the object array argument argTypes to the invoked method isn’t being defined correctly yet, your suggestion does seem to define this argument. Any hints?
    Thanks
    Adam

    java.lang.IllegalArgumentException: object is not an instance of declaring class
    at java.lang.reflect.Method.invoke(Native Method)
    at testinvoke.invoke(testinvoke.java:21)
    at testinvoke.main(testinvoke.java:9)
    ===============================================================================

    import java.io.*;
    import java.util.*;
    import java.lang.reflect.*;
    public class testinvoke
    <
    public static void main(String args[])
    <
    invoke();
    >

    public static void invoke()
    <
    Object[] t = new Object[]<"1

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