如何在骆驼处理器中使用属性占位符

Question

我正在用骆驼编写一些路由，并且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...我想读取处理器中{{MAIL}}的值，但我不知道如何。

我想这些东西：

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); 
    } 
} 

你能帮助我吗？

感谢

Answer 1

上有CamelContext API来做到这一点：

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