Camel 3.2 and Javascript

Question

我们正忙于将骆驼路线从2.x升级到3.2，我们遇到了JavaScript使用问题。在我们的应用程序中，JavaScript被广泛用于将简单的JSON转换为其他JSON。我们也广泛使用XML DSL。我们的典型模式类似于以下简化代码：

<transform id="transform_customer_response">
<javaScript>
<![CDATA[
(function map() {
var msg = {
name: request.body.name,
hash: request.headers.hash
};            
return JSON.stringify(msg);
})()
]>
</javaScript>
</transform>

我知道<javaScript>语言组件在Camel3中已经被弃用并删除，因为最新的文档没有显示这一点。然而，似乎仍然通过<language language="javascript">标签支持JavaScript。

其他背景信息：

1. Springboot版本：2.2.6.RELEASE
2. Apache Camel版本：3.2.0
3. JDK/VM:OpenJDK 64位服务器VM GraalVM CE 20.0.0(内部版本11.0.6+9-jvmci-20.0-b02，混合模式，共享(
4. 此处链接到Camel文档：https://camel.apache.org/components/3.2.x/language-component.html

我尝试将上面的代码翻译成下面的代码，但得到了No language could be found for: javascript异常。

<language language="javascript">

(function map() {
var msg = {
name: request.body.name,
hash: request.headers.hash
};          
return JSON.stringify(msg);
})()

</language>

完整堆栈跟踪：

org.apache.camel.FailedToCreateRouteException: Failed to create route createCustomerRoute at: >>> Transform[javascript{

(function map() {
var msg = {
name: request.body.name,
hash: request.headers.hash
};          
return JSON.stringify(msg);
})()

}] <<< in route: Route(createCustomerRoute)[From[direct:create_customer] -> [... because of No language could be found for: javascript
at org.apache.camel.reifier.RouteReifier.doCreateRoute(RouteReifier.java:393) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.RouteReifier.createRoute(RouteReifier.java:117) ~[camel-core-engine-3.2.0.jar:3.2.0]
at `No language could be found for: javascript`org.apache.camel.impl.DefaultCamelContext.startRouteDefinitions(DefaultCamelContext.java:353) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.impl.DefaultCamelContext.startRouteDefinitions(DefaultCamelContext.java:327) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.impl.engine.AbstractCamelContext.doInit(AbstractCamelContext.java:2598) ~[camel-base-3.2.0.jar:3.2.0]
at org.apache.camel.support.service.BaseService.init(BaseService.java:83) ~[camel-api-3.2.0.jar:3.2.0]
at org.apache.camel.impl.engine.AbstractCamelContext.init(AbstractCamelContext.java:2431) ~[camel-base-3.2.0.jar:3.2.0]
at org.apache.camel.support.service.BaseService.start(BaseService.java:111) ~[camel-api-3.2.0.jar:3.2.0]
at org.apache.camel.impl.engine.AbstractCamelContext.start(AbstractCamelContext.java:2448) ~[camel-base-3.2.0.jar:3.2.0]
at org.apache.camel.spring.SpringCamelContext.start(SpringCamelContext.java:121) ~[camel-spring-3.2.0.jar:3.2.0]
at org.apache.camel.spring.CamelContextFactoryBean.start(CamelContextFactoryBean.java:373) ~[camel-spring-3.2.0.jar:3.2.0]
at org.apache.camel.spring.CamelContextFactoryBean.onApplicationEvent(CamelContextFactoryBean.java:420) ~[camel-spring-3.2.0.jar:3.2.0]
at org.apache.camel.spring.CamelContextFactoryBean.onApplicationEvent(CamelContextFactoryBean.java:94) ~[camel-spring-3.2.0.jar:3.2.0]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:897) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) ~[spring-boot-2.2.6.RELEASE.jar:2.2.6.RELEASE]
at com.ventia.nexusarchetype.NexusArchetypeApplication.main(NexusArchetypeApplication.java:12) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.2.6.RELEASE.jar:2.2.6.RELEASE]
Caused by: org.apache.camel.NoSuchLanguageException: No language could be found for: javascript
at org.apache.camel.impl.engine.DefaultLanguageResolver.noSpecificLanguageFound(DefaultLanguageResolver.java:92) ~[camel-base-3.2.0.jar:3.2.0]
at org.apache.camel.impl.engine.DefaultLanguageResolver.resolveLanguage(DefaultLanguageResolver.java:68) ~[camel-base-3.2.0.jar:3.2.0]
at org.apache.camel.impl.engine.AbstractCamelContext.resolveLanguage(AbstractCamelContext.java:1726) ~[camel-base-3.2.0.jar:3.2.0]
at `No language could be found for: javascript`org.apache.camel.reifier.language.ExpressionReifier.createExpression(ExpressionReifier.java:116) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.AbstractReifier.createExpression(AbstractReifier.java:102) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.TransformReifier.createProcessor(TransformReifier.java:34) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.ProcessorReifier.makeProcessor(ProcessorReifier.java:766) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.ProcessorReifier.addRoutes(ProcessorReifier.java:511) ~[camel-core-engine-3.2.0.jar:3.2.0]
at org.apache.camel.reifier.RouteReifier.doCreateRoute(RouteReifier.java:391) ~[camel-core-engine-3.2.0.jar:3.2.0]
... 32 common frames omitted

我试过用groovy制作No language could be found for: groovy。然后，我为groovy添加了一个依赖项，如下所示：

<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-groovy-starter</artifactId>
<!-- use the same version as your Camel core version -->
</dependency>

这是可行的，我可以使用groovy转换一个实体，并且没有任何问题。因此，我缺少一个javascript依赖项/start，但当我尝试在下面添加依赖项时，却找不到它。我也检查了maven，我找不到Camel3.2的cameljavascript启动器。

<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-javascript-starter</artifactId>
<!-- use the same version as your Camel core version -->
</dependency>

看起来JavaScript已经完全被弃用了。然而，文件仍然暗示它是可用的。

请参阅以下文档片段：

语言名称：

必需设置要使用的语言的名称。该值可以是以下值之一：bean、constant、exchangeProperty、file、groovy、header、javascript、jsonpath、mvel、ognl、ref、simple、spel、sql、terser、tokenize、xpath、xquery、xtokenize

简而言之，要么Camel 3.2的依赖项丢失，要么Javascript已被弃用。还是我完全错过了什么。

Answer 1

Javascript语言是camel-script依赖项的一部分。它在2.x中已被弃用，并在3.x中与CAMEL-13113一起删除。这是因为camel-script中大量使用的Nashorn引擎在JDK11(JEP 335(中已被弃用，并计划从下一个JDK版本(JEP 372(中删除。

目前，Apache Camel没有直接的替代品。我已经记录了CAMEL-14970来寻找替代发动机。