Solution to NoSuchMethodException exception in Java

Java is a very important programming language that is widely used in enterprise-level software development and mobile application development. During the development and operation of Java programs, various exceptions are often encountered, among which NoSuchMethodException is a common one. This article will introduce the causes and solutions of the NoSuchMethodException exception, helping Java programmers to quickly locate and solve the exception.

1. Cause of NoSuchMethodException exception

NoSuchMethodException exception indicates that the called method does not exist. Usually, this exception occurs for the following reasons:

1. The called method name is wrong: In Java programs, method names are case-sensitive. If the method name is incorrectly specified or case is ignored, a NoSuchMethodException will be thrown.
2. The parameter type of the called method does not match the parameter type defined by the method: In Java, the parameter type of the method must be specified when the method is called. If the specified parameter type does not match the parameter type defined by the method, , a NoSuchMethodException exception will be thrown.
3. The access modifier of the called method is incorrect: If the access modifier of the called method is private or protected, and the method is attempted to be accessed through reflection, a NoSuchMethodException will be thrown.
4. The called method is in an incorrect class or interface: If the called method does not exist in the specified class or interface, a NoSuchMethodException exception will be thrown.

2. Solutions to NoSuchMethodException

If NoSuchMethodException occurs in a Java program, here are several common solutions for your reference:

1. Check whether the method name is correct: Check whether the method name specified in the code is consistent with the actual method name, and whether the case is correct.
2. Check whether the parameter type of the method is correct: If the method is called through reflection, you should use the getMethod() or getDeclaredMethod() method in the Class object to obtain the parameter type of the method, and ensure that the specified parameter type matches the method definition The parameter types are consistent.
3. Modify the access modifier of the method: If the access modifier of the called method is private or protected, you can solve this exception by adding the public modifier to the class to which the method belongs. This way, the method can be accessed through reflection.
4. Check whether the class or interface where the method is located is correct: ensure that the specified method exists in the specified class or interface. In the case of method overloading, interface implementation, or anonymous inner classes via inheritance, you need to carefully examine the hierarchy between classes and interfaces.

5. Check whether the version of the dependent package or class library is correct: A common situation is that the version of the dependent package or class library used in the code is incorrect, causing the NoSuchMethodException exception to be thrown.

3. Conclusion

NoSuchMethodException exceptions often occur in Java programming, and usually mean that programmers have some errors in program design and implementation. Java programmers should carefully check variables, method names, parameter types, etc. in the code, and solve problems promptly if problems are found. This article introduces several solutions, hoping to be helpful to Java programmers.

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