桥接模式-Bridge
桥梁模式的用意是"将抽象化(Abstraction)与实现化(Implementation)脱耦, 将"类的功能层次结构" 与 "类的实现层次结构"分离为两个独立的类层次结构.
类的实现层次接口
DisplayImpl接口
public interface DisplayImpl { void rawOpen(); void rawPrint(); void rawClose(); }
StringDisplayImpl类
public class StringDisplayImpl implements DisplayImpl { private String string; private int width; public StringDisplayImpl(String string) { this.string = string; this.width = string.getBytes().length; } public void rawOpen() { printLine(); } public void rawPrint() { System.out.println("|" + string + "|"); } public void rawClose() { printLine(); } private void printLine() { System.out.print("+"); for (int i = 0; i < width; i++) { System.out.print("-"); } System.out.println("+"); } }
类的功能层次结构
Display类
在功能实现的最高层上关联了DisplayImpl接口, 在此处进行了桥接.
public class Display { private DisplayImpl impl; public Display(DisplayImpl impl) { this.impl = impl; } public void open() { impl.rawOpen(); } public void print() { impl.rawPrint(); } public void close() { impl.rawClose(); } public final void display() { open(); print(); close(); } }
CountDisplay类
在Display类的基础上, 进行功能上的扩展. 扩展一个multiDisplay()功能.
public class CountDisplay extends Display { public CountDisplay(DisplayImpl impl) { super(impl); } public void multiDisplay(int times) { open(); for (int i = 0; i < times; i++) { print(); } close(); } }
Main
用于测试运行
public class Main { public static void main(String[] args) { Display d1 = new Display(new StringDisplayImpl("Hello, China.")); Display d2 = new CountDisplay(new StringDisplayImpl("Hello, World.")); CountDisplay d3 = new CountDisplay(new StringDisplayImpl("Hello, Universe.")); d1.display(); d2.display(); d3.display(); d3.multiDisplay(5); } }
原文地址:https://www.cnblogs.com/noKing/p/9010888.html
时间: 2024-10-11 02:38:42