如何在 Camel 处理器中使用 属性 占位符

How to use property placeholder inside a Camel Processor

我正在用 camel 编写一些路由,我想使用处理器进行一些转换。我有一个属性文件,它工作正常。

    from(URI_LOG)
    .routeId("{{PREFIX_LOG}}.prepareForMQ") 
    .log("Mail to: {{MAIL}}") //The value is read from a property file
    .process(new ProcessorPrepareMail())
    .log("${body}");

现在...我想在处理器中读取 {{MAIL}} 的值,但我不知道如何读取。

我试过这些东西:

public class ProcessorPrepareMail implements Processor
{

    @Override
    public void process(Exchange exchange) throws Exception
    {
        //Plan A: Does not work.... I get an empty String
        String mail = exchange.getProperty("MAIL", String.class);

        //Plan B: Does not work.... I get the String "{{MAIL}}"
        Language simple = exchange.getContext().resolveLanguage("simple");
        Expression expresion = simple.createExpression("{{MAIL}}");
        String valor = expresion.evaluate(exchange, String.class);

        //Plan C: Does not work. It activates the default error handler
        Language simple = exchange.getContext().resolveLanguage("simple");
        Expression expresion = simple.createExpression("${MAIL}");
        String valor = expresion.evaluate(exchange, String.class);
    }
}

你能帮帮我吗?

谢谢

CamelContext 上有 API 可以做到这一点:

String mail = exchange.getContext().resolvePropertyPlaceholders("{{MAIL}}");