解决问题
客户端调用逻辑与业务代码有效隔离，使得客户端调用只和Facade进行交互，内部的调用逻辑由Facade进行实现。此模式也可以和接口化编程结合，进一步降低客户端与业务逻辑的耦合
应用场景
它主要应用在代码结构的设计，合理组织代码结构
原理图（UML）
示例
此模式非常常见，这里就直接使用wikipedia上的代码
/* Complex parts */class CPU {public void freeze() { ... }public void jump(long position) { ... }public void execute() { ... }
}class HardDrive {public byte[] read(long lba, int size) { ... }
}class Memory {public void load(long position, byte[] data) { ... }
}/* Facade */class ComputerFacade {private CPU processor;private Memory ram;private HardDrive hd;public ComputerFacade() {this.processor = new CPU();this.ram = new Memory();this.hd = new HardDrive();}public void start() {processor.freeze();ram.load(BOOT_ADDRESS, hd.read(BOOT_SECTOR, SECTOR_SIZE));processor.jump(BOOT_ADDRESS);processor.execute();}
}/* Client */class You {public static void main(String[] args) {ComputerFacade computer = new ComputerFacade();computer.start();}
}
复制代码参考
https://en.wikipedia.org/wiki/Facade_pattern#Java
