一般主要应用在OOP开发中的编译器的开发中,所以适用面比较窄。
Context类是一个上下文环境类,Plus和Minus分别是用来计算的实现
Context类是一个上下文环境类,Plus和Minus分别是用来计算的实现
public interface Expression { public int interpret(Context context); } public class Plus implements Expression { @Override public int interpret(Context context) { return context.getNum1()+context.getNum2(); } } public class Minus implements Expression { @Override public int interpret(Context context) { return context.getNum1()-context.getNum2(); } } public class Context { private int num1; private int num2; public Context(int num1, int num2) { this.num1 = num1; this.num2 = num2; } public int getNum1() { return num1; } public void setNum1(int num1) { this.num1 = num1; } public int getNum2() { return num2; } public void setNum2(int num2) { this.num2 = num2; } } public class Test { public static void main(String[] args) { // 计算9+2-8的值 int result = new Minus().interpret((new Context(new Plus() .interpret(new Context(9, 2)), 8))); System.out.println(result); } }
输出正确的结果:3。解释器模式用来做各种各样的解释器,如正则表达式等的解释器等等!