Java Coding Problems

170. Implementing the Strategy pattern

The classic Strategy pattern is pretty straightforward. It consists of an interface that represents a family of algorithms (strategies) and several implementations of this interface (each implementation is a strategy).

For example, the following interface unifies the strategies for removing characters from the given string:

public interface RemoveStrategy {  String execute(String s);}

First, we will define a strategy for removing numeric values from a string:

public class NumberRemover implements RemoveStrategy {  @Override  public String execute(String s) {    return s.replaceAll("\\d", "");  }}

Then, we will define a strategy for removing white spaces from a string:

public class WhitespacesRemover implements ...