将一个类的接口转换成客户希望的另一个接口。
public interface Logger {
void log(String message);
}
public class OldLogger implements Logger{
public void log(String message) {
System.out.println(message);
}
}
public class NbLogger implements Logger {
@Override
public void log(String message) {
System.out.println("[INFO]\t" + Thread.currentThread().getName() + "\t" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "\t" + message);
}
}
public class LoggerAdapter implements Logger {
private final Logger logger = new NbLogger();
@Override
public void log(String message) {
logger.log(message);
}
}
public class Client {
public static void main(String[] args) {
new LoggerAdapter().log("hello");
}
}
[INFO] main 2024-01-02 15:54:03 hello
public interface Logger {
void log(String message);
}
OldLogger和NbLogger大概率是通过依赖引入的,所以大概率会引入NbLogger然后排除OldLogger
通过spring自动注入实现开闭原则
@Component("logger")
public class LoggerAdapter implements Logger {
@Autowired
private Logger logger;
@Override
public void log(String message) {
logger.log(message);
}
}
如果OldLogger和NbLogger为自定义组件,只需要将NbLogger加入容器,@SpringBootApplication(exclude = {OldLogger.class})即可实现开闭原则
HandlerAdapter
public class ServletRequestWrapper implements ServletRequest {
private ServletRequest request;
}