如何为Apache骆驼Groovy脚本组件设置属性

Question

I'm using apache camel script component to call a external groovy file.

     from("activemq:queue:test.ChooseIManger")
     .script().groovy("resource:classpath:tests/port/test.gsh")

I want to pass some properties when calling this script. I can do that with simple java code as follows.

        Binding binding = new Binding();
        binding.setProperty("INPUTS", inputs);
        binding.setProperty("RESULT", results);

        GroovyShell shell = new GroovyShell(binding); 
        Object script = shell.evaluate(getScript("tests/port/test.gsh"));

But how we can bind properties in camel router like this.

Thanx

Answer 1

According to the documentation it seems you should be able to overload the default Groovy instance by using a custom GroovyShellFactory.

Something like this according to the information you've provided:

public class CustomGroovyShellFactory implements GroovyShellFactory {

  public GroovyShell createGroovyShell(Exchange exchange) {
    Binding binding = new Binding();
    binding.setProperty("INPUTS", inputs);
    binding.setProperty("RESULT", results);
    return new GroovyShell(binding);
  }
}

And then add that bean to your context.

Answer 2

This may not be possible in Camel. In method evaluate of class org.apache.camel.language.groovy.GroovyExpression , all previously set bindings simply get overridden with the Camel bindings (eg camelContext ) instead of being merged.

public <T> T evaluate(Exchange exchange, Class<T> type) {
    Script script = instantiateScript(exchange);
    script.setBinding(createBinding(exchange));
    Object value = script.run();

    return exchange.getContext().getTypeConverter().convertTo(type, value);
}

Thus all of your bindings are lost. I guess this cannot be resolved without changing Camel itself.

But, if anyone has a solution for this, I'd really like to know it.