ApacheCamel-调用简单的语言没有副作用

Question

是否可以在路由内直接使用Simple语言调用对象而不产生副作用？我尝试过的两种方法是：；

.toD("${header.exchangeHelper.inc1()}") //works but fails if there is a return type from the called method
.bean(new Simple("${header.exchangeHelper.inc1()}")) //works but sets the body to false

两者都没有给出理想的解决方案。

Answer 1

您可以将结果存储到交换属性或标头中。通过这种方式，您将保留原始主体，并从方法中获得结果，以备以后需要。或者，您也可以使用处理器来调用该方法。

对于这样的事情，Java DSL通常比使用简单语言更好，因为它们受益于IDE的重构工具、错误突出显示和许多形式的linting。

package com.example;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import org.apache.camel.Exchange;
import org.apache.camel.RoutesBuilder;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.mock.MockEndpoint;
import org.apache.camel.test.junit4.CamelTestSupport;
import org.junit.Test;
public class ExampleTest extends CamelTestSupport {

ExchangeHelper exchangeHelper = mock(ExchangeHelper.class);
@Test
public void useSetPropertyTest() throws Exception {
MockEndpoint resultMockEndpoint = getMockEndpoint("mock:result");
resultMockEndpoint.expectedMessageCount(1);
resultMockEndpoint.message(0).body().isEqualTo("Hello");
when(exchangeHelper.inc1()).thenReturn(true);
template.sendBodyAndHeader("direct:useSetProperty", "Hello", 
"exchangeHelper", exchangeHelper);
verify(exchangeHelper, times(1)).inc1();
resultMockEndpoint.assertIsSatisfied();
}
@Test
public void justUseProcessorTest() throws Exception {
MockEndpoint resultMockEndpoint = getMockEndpoint("mock:result");
resultMockEndpoint.expectedMessageCount(1);
resultMockEndpoint.message(0).body().isEqualTo("Hello");
when(exchangeHelper.inc1()).thenReturn(true);
template.sendBody("direct:justUseProcessor", "Hello");
verify(exchangeHelper, times(1)).inc1();
resultMockEndpoint.assertIsSatisfied();
}
@Test
public void useHeaderFromProcessorTest() throws Exception {
MockEndpoint resultMockEndpoint = getMockEndpoint("mock:result");
resultMockEndpoint.expectedMessageCount(1);
resultMockEndpoint.message(0).body().isEqualTo("Hello");
when(exchangeHelper.inc1()).thenReturn(true);
template.sendBodyAndHeader("direct:useHeaderFromProcessor", "Hello", 
"exchangeHelper", exchangeHelper);
verify(exchangeHelper, times(1)).inc1();
resultMockEndpoint.assertIsSatisfied();
}
@Override
protected RoutesBuilder createRouteBuilder() throws Exception {
return new RouteBuilder(){
@Override
public void configure() throws Exception {

from("direct:useSetProperty")
.setProperty("result")
.simple("${header.exchangeHelper.inc1()}")
.log("Body: ${body} Result header: ${exchangeProperty.result}")
.to("mock:result")
.removeProperty("result");
from("direct:justUseProcessor")
.process( ex -> { exchangeHelper.inc1(); })
.log("Body: ${body}")
.to("mock:result");
from("direct:useHeaderFromProcessor")
.process( ex -> {  
ex.getMessage()
.getHeader("exchangeHelper", ExchangeHelper.class)
.inc1();
})
.log("Body: ${body}")
.to("mock:result");
}
};
}
interface ExchangeHelper {
public boolean inc1();
}
}

Answer 2

未尝试，但为什么不使用窃听EIP向您的requestHelper方法发出一个额外的(分离的！(请求？

类似于：

from("direct:demo")
.wireTap("bean:${header.exchangeHelper.inc1()}")
.to("direct:doSomething");

Answer 3

您可以简单地使用骆驼脚本，类似于

from("direct:exampleScript")
.script().simple("${header.exchangeHelper.inc1()}")
.log("End")
;