Java通过central config 开关实现双写控制

 抽象类：

import com.citi.risk.core.configuration.api.Configuration;

public abstract class AbstractXXXSwitcher {

    @Autowised
    private Configuration configuration;

    private I executor_1;

    private I executor_2;

    protected AbstractClimateRiskSwitcher(I executor_1, I executor_2) {
        this.executor_1 = executor_1;
        this.executor_2 = executor_2;
    }

    protected  R read(Function function) {
        R data;
        int mode = getAccessMode();
        if (mode == 0) {
            data = function.apply(executor_1);
        } else {
            data = function.apply(executor_2);
        }

        return data;
    }

    protected void readAndSet(Consumer consumer) {
        int mode = getAccessMode();
        if (mode == 0) {
            consumer.accept(executor_1);
        } else {
            consumer.accept(executor_2);
        }
    }

    protected void write(Consumer consumer) {
        int mode = getAccessMode();
        try {
            consumer.accept(executor_2);
        } catch (Exception e) {
            LOGGER.error("Exception thrown in write of MS", e);
        }
        if (mode == 0 || mode == 1) {
            consumer.accept(executor_1);
        }
    }

    protected  R writeAndGet(Function function) {
        R data;
        int mode = getAccessMode();
        if (mode == 0) {
            try {
                function.apply(executor_2);
            } catch (Exception e) {
                LOGGER.error("Exception thrown in writeAndGet of MS", e);
            }
            data = function.apply(executor_1);
        } else if (mode == 1) {
            data = function.apply(executor_2);
            function.apply(executor_1);
        } else {
            data = function.apply(executor_2);
        }

        return data;
    }

    /**
     * 
     * 0: write to both executor_1 and executor_2, read from executor_1.
     * 1: write to both executor_1 and executor_2, read from executor_2.
     * 2: write to executor_2 only, read from executor_2.
     *
     * @return access mode.
     */
    private int getAccessMode() {
        return Integer.parseInt(configuration.getPrefixProperties("PREFIX").getProperty("PROPERTY", "0"));
    }
}

 最后获取开关的值可以配置在central config里，通过更改这个值就可以实现对双写的控制

configuration.getPrefixProperties("PREFIX").getProperty("PROPERTY", "0")

具体用法：

@Singleton
public class XXXHandlerProxy extends AbstractXXXSwitcher implements XXXHandler {

    @Inject
    public XXXHandlerProxy(Handler1 handler1 , Handler2 handler2) {
        super(handler1 , handler2);
    }

    @Override
    public Object foo(Object o) {
        return read(handler -> handler.method(o));
    }
}

XXXHandler 接口： 

public interface XXXHandler {

    Object method(Object o);
}