fork download
copy 
  1. interface Analyzer {
  2.     String performAnalysis(Calculator calculator);
  3. }
  4.  
  5. interface Calculator {
  6.     int computeValue();
  7. }
  8.  
  9. class CalculatorImpl implements Calculator {
  10.     @Override
  11.     public int computeValue() {
  12.         return 5;
  13.     }
  14. }
  15.  
  16. class AnalyzerImpl implements Analyzer {
  17.     @Override
  18.     public String performAnalysis(Calculator calculator) {
  19.         return "Result: " + calculator.computeValue();
  20.     }
  21. }
  22.  
  23. class CalculatorDecorator implements Calculator {
  24.     Calculator delegate;
  25.     public CalculatorDecorator(Calculator delegate) {
  26.         this.delegate = delegate;
  27.     }
  28.  
  29.     @Override
  30.     public int computeValue() {
  31.         return delegate.computeValue();
  32.     }
  33. }
  34.  
  35.  
  36. class Main {
  37.  
  38.     // Tweak a calculator to return 1337.
  39.     public static Calculator tweakCalculator(Calculator untweakedCalculator) {
  40.         return new CalculatorDecorator(untweakedCalculator) {
  41.             @Override
  42.             public int computeValue() {
  43.                 return 1337;              // tweaked value!
  44.             }
  45.         };
  46.     }
  47.  
  48.     // Test the analyzer tweaking.
  49.     public static void main(String[] args) {
  50.         System.out.println(new AnalyzerImpl().performAnalysis(tweakCalculator(new CalculatorImpl())));
  51.     }
  52. }
  53.  
Success #stdin #stdout 0.03s 245632KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Result: 1337
https://ideone.com/Db5fv
language:
Java (HotSpot 12)
created:
11 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!