设计模式之外观模式

外观模式类似于传统的三层架构,例子中的CPU类属于数据访问层,Computer类属于业务逻辑层,Client服务端属于表现层~

Java这是一个抽象的示例。一个客户“you”通过外观接口“computer”获取计算机内部复杂的系统信息。/* Complex parts */class CPU {public void freeze() { ... }public void jump(long position) { ... }public void execute() { ... }}class Memory {public void load(long position, byte[] data) {...}}class HardDrive {public byte[] read(long lba, int size) {...}}/* Façade */class Computer {public void startComputer() {cpu.freeze();memory.load(BOOT_ADDRESS, hardDrive.read(BOOT_SECTOR, SECTOR_SIZE));cpu.jump(BOOT_ADDRESS);cpu.execute();}}/* Client */class You {public static void main(String[] args) {Computer facade = new Computer();facade.startComputer();}}