自定义AlwaysDeleteProcessStrategy在Camel字符串端点失效求助

我创建了一个继承自GenericFileDeleteProcessStrategy的自定义处理策略类AlwaysDeleteProcessStrategy：

@Component
public class AlwaysDeleteProcessStrategy<T> extends GenericFileDeleteProcessStrategy<T> {

    private static final Logger LOGGER = LoggerFactory.getLogger(AlwaysDeleteProcessStrategy.class);

    @Override
    public void rollback(GenericFileOperations<T> operations, GenericFileEndpoint<T> endpoint, Exchange exchange, GenericFile<T> file) throws Exception {
        LOGGER.info("Deleting file despite exception");
        super.commit(operations, endpoint, exchange, file);
    }
}

使用Endpoint DSL方式配置端点时该类可正常工作，但通过字符串格式构建端点时失效：

// 正常工作
from(file("src/test/resources/input").advanced().processStrategy(new AlwaysDeleteProcessStrategy()))  

// 失效
from("file://src/test/resources/input?processStrategy=#alwaysDeleteProcessStrategy")

此时抛出如下异常：

Caused by: org.apache.camel.NoSuchBeanException: No bean could be found in the registry for: alwaysDeleteProcessStrategy of type: org.apache.camel.component.file.GenericFileProcessStrategy
    at org.apache.camel.support.CamelContextHelper.mandatoryLookupAndConvert(CamelContextHelper.java:253)
    at org.apache.camel.support.EndpointHelper.resolveReferenceParameter(EndpointHelper.java:376)
    at org.apache.camel.support.EndpointHelper.resolveReferenceParameter(EndpointHelper.java:336)
    at org.apache.camel.support.component.PropertyConfigurerSupport.property(PropertyConfigurerSupport.java:55)
    at org.apache.camel.component.file.FileEndpointConfigurer.configure(FileEndpointConfigurer.java:131)
    at org.apache.camel.support.PropertyBindingSupport.setSimplePropertyViaConfigurer(PropertyBindingSupport.java:733)
    ... 43 common frames omitted

我已尝试手动创建Bean（即使@Component注解已存在），但问题仍未解决。如何让两种配置方式都正常工作？

解决方案 #

问题根源 #

Camel在解析字符串端点的processStrategy参数时，会严格按照GenericFileProcessStrategy类型查找Bean，但你的泛型类AlwaysDeleteProcessStrategy<T>在Spring容器中注册的是带泛型参数的类型，导致Camel的类型匹配和转换逻辑失败。

方案1：移除泛型参数，使用具体类型 #

修改自定义策略类，将泛型替换为具体的Object类型，这样Spring注册的Bean会被识别为兼容GenericFileProcessStrategy的类型：

@Component
public class AlwaysDeleteProcessStrategy extends GenericFileDeleteProcessStrategy<Object> {

    private static final Logger LOGGER = LoggerFactory.getLogger(AlwaysDeleteProcessStrategy.class);

    @Override
    public void rollback(GenericFileOperations<Object> operations, GenericFileEndpoint<Object> endpoint, Exchange exchange, GenericFile<Object> file) throws Exception {
        LOGGER.info("Deleting file despite exception");
        super.commit(operations, endpoint, exchange, file);
    }
}

方案2：显式注册Bean并指定目标类型 #

保留泛型类，但通过@Bean注解显式注册Bean，指定返回类型为GenericFileProcessStrategy<?>，确保Camel能识别该Bean：

@Configuration
public class CamelConfig {

    @Bean("alwaysDeleteProcessStrategy")
    public GenericFileProcessStrategy<?> alwaysDeleteProcessStrategy() {
        return new AlwaysDeleteProcessStrategy<>();
    }
}

额外检查点 #

• 确认Spring组件扫描范围包含该策略类所在的包
• 可以通过@Component("alwaysDeleteProcessStrategy")显式指定Bean名称，避免Spring自动生成的名称出现偏差

内容的提问来源于stack exchange，提问作者MarcoB