Apache Camel 中的默认 RoutePolicy

Question

我有以下场景

路由策略：

@Slf4j
@RequiredArgsConstructor
public class LoggingPolicy extends RoutePolicySupport {
    private final String greeting;

    @Override
    public void onExchangeBegin(Route route, Exchange exchange) {
        super.onExchangeBegin(route, exchange);
        log.info("%s from LoggingPolicy".formatted(greeting));
    }
}

基本路由构建器：

public abstract class BaseRouteBuilder
    extends RouteBuilder {
    @Override
    public void configure() throws Exception {

        onException()
            .handled(true)
            .log("Exception occured")
            .end();

        configRoutes();
    }

    abstract void configRoutes();
}

两种实现：

@Component
public class HelloRouteBuilder extends BaseRouteBuilder {
    @Override
    void configRoutes() {
        from("timer:hello?repeatCount=1")
            .routeId("HelloRoute")
            .routePolicy( new LoggingPolicy("Hello"))
            .log("HelloRoute Completed");
    }
}


@Component
public class ByeRouteBuilder extends BaseRouteBuilder {
    @Override
    void configRoutes() {
        from("timer:bye?repeatCount=1")
            .routeId("ByeRoute")
            .routePolicy( new LoggingPolicy("Bye"))
            .log("ByeRoute Completed");
    }
}

最后还有另一个 RouteBuilder - 不是从 BaseRouteBuilder 继承的

@Component
public class AnotherRouteBuilder extends RouteBuilder {
    @Override
    public void configure() throws Exception {
        from("timer:another?repeatCount=1")
            .routeId("AnotherRoute")
            .log("AnotherRoute Completed");
    }
}

一切都按预期进行。

我现在想做的是将 LoggingPolicy 委托给 BaseRouteBuilder，以便

• LoggingPolicy 应用于继承形式

  BaseRouteBuilder

  的所有 RouteBuilder 中的所有路由（在本例中为

  HelloRoute

  和

  ByeRoute

  但不是

  AnotherRoute

  ）

• 构造函数参数 (

  greeting

  ) 默认为

  "Hello"

  ，但可以在路由构建器中覆盖。

在我的实际用例中，我有 100 多个 RouteBuilder，我想向所有这些添加 LoggingPolicy。其中大多数都有默认参数，但我需要覆盖一些路由的参数。

Answer 1

经过相当多的实验，我找到了以下解决方案

public abstract class BaseRouteBuilder
    extends RouteBuilder {
    @Override
    public void configure() throws Exception {

        onException()
            .handled(true)
            .log("Exception occurred")
            .end();


        configRoutes();
        configureRoutes(getContext()).getRoutes()
            .forEach(route -> route.routePolicy(
                getLoggingPolicy()));
    }

    abstract void configRoutes();

    protected RoutePolicy getLoggingPolicy() {
        return new LoggingPolicy(
            getLoggingPolicyGreeting());
    }

    protected String getLoggingPolicyGreeting() {
        return "Hola"; // Default greeting
    }
}

现在在子路由中，我可以覆盖

getLoggingPolicyGreeting

来修改

greeting

的默认

RouteBuilder

甚至整个

LoggingPolicy

使用

getLoggingPolicyGreeting

类似

@Component
public class ByeRouteBuilder extends BaseRouteBuilder {
    @Override
    void configRoutes() {
        from("timer:bye?repeatCount=1")
            .routeId("ByeRoute")
            .log("ByeRoute Completed");
    }

    @Override
    protected String getLoggingPolicyGreeting() {
        return "Bye";
    }
}