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abstract class DBOperator{ public abstract void connDB(); public void openDB(){ System.out.println("打开数据库"); } public void useDB(){ System.out.println 阅读全文
摘要:
abstract class AbstractCommand{ public abstract int execute(int value); public abstract int undo(); public abstract int redo(); } class ConcreteComman 阅读全文
摘要:
public class CPU { public void run(){ System.out.println("处理器运行"); } public void off(){ System.out.println("处理器关闭"); } } public class Disk { public vo 阅读全文