Apache Camel框架集成Spring

Apache Camel提供了和Spring的集成,通过Spring容器(ApplicationContext)来管理Camel的CamelContext,这样的话,就不需要写代码来控制CamelContext的初始化,启动和停止了.Camel会随着Spring的启动而启动起来.

本文将Apache Camel框架入门示例(http://blog.csdn.net/kkdelta/article/details/7231640)中的例子集成到Spring中,下面简单介绍一下集成的基本步骤.

1,新建一个Eclipse工程,将Spring3的jar包,和Camel的jar包配置到工程的classpath.

2,Route类要继承RouteBuilde,如下

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1. public class FileProcessWithCamelSpring extends RouteBuilder {  
2.     @Override  
3.     public void configure() throws Exception {  
4.         FileConvertProcessor processor = new FileConvertProcessor();   
5.         from("file:d:/temp/inbox?delay=30000").process(processor).to("file:d:/temp/outbox");          
6.     }  
7. }  

3,Processor仍然和和入门示例的代码相同.

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1. public class FileConvertProcessor implements Processor{  
2.     @Override  
3.     public void process(Exchange exchange) throws Exception {      
4.         try {  
5.             InputStream body = exchange.getIn().getBody(InputStream.class);  
6.             BufferedReader in = new BufferedReader(new InputStreamReader(body));  
7.             StringBuffer strbf = new StringBuffer("");  
8.             String str = null;  
9.             str = in.readLine();  
10.             while (str != null) {                  
11.                 System.out.println(str);  
12.                 strbf.append(str + " ");  
13.                 str = in.readLine();                  
14.             }  
15.             exchange.getOut().setHeader(Exchange.FILE_NAME, "converted.txt");  
16.             // set the output to the file  
17.             exchange.getOut().setBody(strbf.toString());  
18.         } catch (IOException e) {  
19.             e.printStackTrace();  
20.         }  
21.     }  
22. }  

4,创建一个Spring的配置文件如下:注意要将camel的xmlns加入文件中

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1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans xmlns="http://www.springframework.org/schema/beans"  
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
4.     xmlns:camel="http://camel.apache.org/schema/spring"  
5.     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
6.     http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"  
7.     default-autowire="byName"  default-init-method="init">  
8.     <camelContext id="testCamelContext" xmlns="http://camel.apache.org/schema/spring">  
9.         <package>com.test.camel</package>  
10.     </camelContext>      
11. </beans>  

5,启动Spring容器,Camel会自动启动,不用像入门示例那样CamelContext context = new DefaultCamelContext(), context.addRoutes(..); context.start();

        ApplicationContext ac = new ClassPathXmlApplicationContext("config/cameltest.xml");
        while (true) {
            Thread.sleep(2000);
        }

可见,Camel可以很容易的和Spring集成.

Camel还提供了"Spring DSL"来在XML中配置Route规则,不需要用JAVA类(如上面的FileProcessWithCamelSpring )来实现route.

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1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans xmlns="http://www.springframework.org/schema/beans"  
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
4.     xmlns:camel="http://camel.apache.org/schema/spring"  
5.     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
6.     http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"  
7.     default-autowire="byName"  default-init-method="init">  
8.     <bean id="fileConverter" class="com.test.camel.FileConvertProcessor"/>  
9.     <camelContext id="testCamelContext" xmlns="http://camel.apache.org/schema/spring">  
10.         <route>  
11.             <from uri="file:d:/temp/inbox?delay=30000"/>  
12.             <process ref="fileConverter"/>  
13.             <to uri="file:d:/temp/outbox"/>  
14.         </route>  
15.     </camelContext>  
16. </beans>  

与第五步一样启动Spring容器,Camel会每隔30秒轮询一下看d:/temp/inbox是否有文件,有的话则进行处理.