How to define a method in Java.

In Java, you can define a method using the following syntax:

Modifier returnType methodName (parameterList) {
methodBody
}

以下是一个例子：

This function calculates the sum of two integers provided as input.

In this example, the method has a modifier of public, a return type of int, the method name is add, with a parameter list consisting of two int type parameters, a and b. The code within the method calculates the sum of a and b, and returns the result.

Note: The modifiers and return type of a method are optional. If no modifier is specified, the default visibility is package-private. If no return type is specified, void is used to indicate that the method does not return any value.