<p>I have a method that's about ten lines of code.  I want to create more methods that do exactly the same thing, except for a small calculation that's going to change one line of code.  This is a perfect application for passing in a function pointer to replace that one line, but Java doesn't have function pointers.  What's my best alternative?</p>

Anonymous inner class
Say you want to have a function passed in with a
```
String
```
param that returns an
```
int
```
.
First you have to define an interface with the function as its only member, if you can't reuse an existing one.
```
```
interface StringFunction {
    int func(String param);
}
```
```
A method that takes the pointer would just accept
```
StringFunction
```
instance like so:
```
```
public void takingMethod(StringFunction sf) {
   int i = sf.func("my string");
   // do whatever ...
}
```
```
And would be called like so:
```
```
ref.takingMethod(new StringFunction() {
    public int func(String param) {
        // body
    }
});
```
```
EDIT:
In Java 8, you could call it with a lambda expression:
```
```
ref.takingMethod(param -> bodyExpression);
```
```