解释器模式
解释器模式（Interpreter Pattern）提供了评估语言的语法或表达式的方式，它属于行为型模式。
这种模式实现了一个表达式接口，该接口解释一个特定的上下文。这种模式被用在 SQL 解析、符号处理引擎等。
实际案例
类信息概览：
| 类名 | 说明 |
|---|---|
| Main.java | 方法的总入口 |
| TerminalExpression.java | 解释器 |
| Expression.java | 表达式 |
| OrExpression.java | or 表达式 |
| AndExpression.java | and 表达式 |
定义
- TerminalExpression.java
package com.ryo.design.pattern.note.interpreter;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/14
* @since 1.7
*/
public class TerminalExpression implements Expression {
private String content;
public TerminalExpression(String content) {
this.content = content;
}
@Override
public boolean interpret(String content) {
return this.content.contains(content);
}
}
- Expression.java
package com.ryo.design.pattern.note.interpreter;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/14
* @since 1.7
*/
public interface Expression {
/**
* 解释
* @param content 内容
* @return
*/
boolean interpret(String content);
}
- OrExpression.java
package com.ryo.design.pattern.note.interpreter;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/14
* @since 1.7
*/
public class OrExpression implements Expression {
private Expression expressionOne;
private Expression expressionTwo;
public OrExpression(Expression expressionOne, Expression expressionTwo) {
this.expressionOne = expressionOne;
this.expressionTwo = expressionTwo;
}
@Override
public boolean interpret(String content) {
return expressionOne.interpret(content) || expressionTwo.interpret(content);
}
}
- AndExpression.java
package com.ryo.design.pattern.note.interpreter;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/14
* @since 1.7
*/
public class AndExpression implements Expression {
private Expression expressionOne;
private Expression expressionTwo;
public AndExpression(Expression expressionOne, Expression expressionTwo) {
this.expressionOne = expressionOne;
this.expressionTwo = expressionTwo;
}
@Override
public boolean interpret(String content) {
return expressionOne.interpret(content) && expressionTwo.interpret(content);
}
}
测试
- Main.java
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
* Copyright (c) 2012-2018. houbinbini Inc.
* design-pattern All rights reserved.
*/
package com.ryo.design.pattern.note.interpreter;
/**
* <p> </p>
*
* <pre> Created: 2018/5/21 下午7:29 </pre>
* <pre> Project: design-pattern </pre>
*
* @author houbinbin
* @version 1.0
* @since JDK 1.7
*/
public class Main {
public static void main(String[] args) {
Expression expressionOne = new TerminalExpression("Hello World");
Expression expressionTwo = new TerminalExpression("Hello Mongo");
Expression andExpression = new AndExpression(expressionOne, expressionTwo);
boolean one = andExpression.interpret("Hello");
Expression andExpression1 = new AndExpression(expressionOne, expressionTwo);
boolean two = andExpression1.interpret("World");
Expression orExpression = new OrExpression(expressionOne, expressionTwo);
boolean three = orExpression.interpret("World");
System.out.println(one);
System.out.println(two);
System.out.println(three);
}
}
- 测试结果
true
false
true
实现方式
UML & Code
UML
UML 图示如下
Code
代码地址
