Apache-Camel-简单例子

1、一 demo工程1.下面给出一个从from到to有中间流程process处理的例子public class FileMoveWithCamel public static void main(String args) throws Exception CamelContext context = new DefaultCamelContext(); context.addRoutes(new RouteBuilder() /将d:/temp/inbox/下的文件经过process处理移到d:/temp/outbox public void configure() from("file

2、:d:/temp/inbox?noop=true").process(new FileConvertProcessor().to("file:d:/temp/outbox"); ); context.start(); boolean loop =true; while(loop) Thread.sleep(9000); context.stop(); class FileConvertProcessor implements Processor Override public void process(Exchange exchange) throws Excep

3、tion try InputStream body = exchange.getIn().getBody(InputStream.class); BufferedReader in = new BufferedReader(new InputStreamReader(body); StringBuffer strbf = new StringBuffer(""); String str = null; str = in.readLine(); while (str != null) System.out.println(str); strbf.append(str + &q

4、uot; "); str = in.readLine(); exchange.getOut().setHeader(Exchange.FILE_NAME, "converted.txt"); exchange.getOut().setBody(strbf.toString(); catch (IOException e) e.printStackTrace(); 推荐精选2.下面这个例子是每隔10秒访问一次http请求，并将访问到的内容写入文件 /* *1 Create a CamelContext. 2 Optionally, configure compone

5、nts or endpoints. 3 Add whatever routing rules you wish using the DSL and RouteBuilder or using Xml Configuration. 4 Start the context. */public class HttpPollWithQuartzCamel public static void main(String args) throws Exception CamelContext context = new DefaultCamelContext(); context.addRoutes(new

6、 RouteBuilder() public void configure() from("quartz:/report?cron=10 * * * * ?&stateful=true") .to("") .to("file:d:/temp/outbox?fileName=httpindex2.csv"); ); context.start(); boolean loop = true; while (loop) Thread.sleep(25000); context.stop(); 3. 在做系统集成的时候,必不可少的任务

7、就是将数据从一种格式转换为另一种格式,再把转换后的格式发到目标系统,在此用实例介绍一下Camel中利用Freemarker做数据转换.a :Freemarker的模板如下:<?xml version="1.0" encoding="UTF-8"?><people  xmlns:h="/TR/html4/">    <#escape x as x?xml>    <#list body.peop

8、leList as p>    <person id="000001" age="20">        <name>            <family>$p.fname</family>            <given&

9、gt;$p.gname</given>        </name>        <email>$p.email</email>        <link manager="$p.manager" />        <#if p.level = "L1&quo

10、t;>        <l1tag>xxx</l1tag>推荐精选        </#if>    </person>    </#list>    </#escape></people>b :与之对应的Java对象如下:每一个person节点对应一个ValueObject放在XMLTemplat

11、eParameter的peopleList里面.public class XMLTemplateParameter     private String fileName;        private List<ValueObject> peopleList = new ArrayList<ValueObject>();    public List<ValueObject> getPeopleList()    &#

12、160;    return peopleList;        public void setPeopleList(List<ValueObject> peopleList)         this.peopleList = peopleList;        public String getFileName()      &

13、#160;  return fileName;        public void setFileName(String fileName)         this.fileName = fileName;    public class ValueObject     private String fname;    private String gname; 

14、   private String email;    private String manager;    private String level;c :Route代码如下:public class CamelFreemarkerRoute extends RouteBuilder     public void configure() throws Exception         from("quartz:

15、/report?cron=10 * * * * ?&stateful=true")        .beanRef("fmBean","prepareFMValues")         .to("freemarker:com/test/camel/freemarker/test.ftl")        .to("fi

16、le:d:/temp/outbox?fileName=fm.xml");        推荐精选d :Route里用到的bean如下:xmlTemplateParameter做为顶级对象放在body里面,Freemarker里取数据的body.peopleList就对应于xmlTemplateParameter.peopleListpublic class FmProcessorBean         public void prepareFMValues(Exc

17、hange exchange)        XMLTemplateParameter xmlTemplateParameter = new XMLTemplateParameter();        ValueObject val = null;        for(int i=0;i<3;i+)           

18、0;val = new ValueObject();                    val.setFname("Yao");            val.setGname("Yorker" +i);            

19、;val.setEmail("test");            val.setManager("m&an<ager");            val.setLevel("L" + i);            xmlTemplateParameter

20、.getPeopleList().add(val);                                    exchange.getIn().setBody(xmlTemplateParameter);        e :Spring的配置文件如下:&

21、lt;beans xmlns="/schema/beans" xmlns:xsi="/2001/XMLSchema-instance" xmlns:camel="/schema/spring" xsi:schemaLocation="/schema/beans http:/www.springframewo

22、/schema/beans/spring-beans-3.0.xsd /schema/spring /schema/spring/camel-spring.xsd" default-autowire="byName" default-init-method="init">    <bean id="fmBean" class="com.test.camel

23、.freemarker.FmProcessorBean"/>    <camelContext id="testCamelContext" xmlns="/schema/spring">        <package>com.test.camel.freemarker</package>    </camelContext>&#

24、160;   </beans>f :启动Spring,在D:tempoutbox文件夹下,每隔10秒钟,会根据freemarker模板生成一个fm.xml文件.        ApplicationContext ac = new ClassPathXmlApplicationContext("config/camelFreemarker.xml");        while (true)   

25、60;        Thread.sleep(2000);        对本例beanRef("fmBean","prepareFMValues")的解释:推荐精选其意思是调用fmBean的prepareFMValues方法,Camel会负责将message的body绑定到要调用方法的第一个参数上面,其中可能做相应的类型转换.(本例中的方法的第一个参数为Exchange,没有转换的过程 ),这里给一个如下示例图解释这个绑定转换的过程

26、:Camel将Exchange的的input message(exchange.getIn()转换为String,绑定到mtd方法的name参数上.4下面是一个路由选择的例子 public class EIP /* * param * return * 方法描述 * author CaiWen * throws Exception * createTime 2014-11-19 * 接口名 */public static void main(String args) throws Exception ConnectionFactory conn = new ActiveMQConnection

27、Factory("vm:/localhost");CamelContext context = new DefaultCamelContext(); context.addComponent("jms", JmsComponent.jmsComponentAutoAcknowledge(conn); context.addRoutes(new RouteBuilder() public void configure() from("file:d:/temp/inbox?noop=true").to("jms:incoming

28、Orders"); from("jms:incomingOrders").choice().when(header("CamelFileName").endsWith(".xml") .to("jms:xmlOrders").when(header("CamelFileName").endsWith(".csv") .to("jms:csvOrders"); from("jms:csvOrders").process(new

29、Processor() Override public void process(Exchange arg0) throws Exception System.out.println("Recive xml order :"+arg0.getIn().getHeader("CamelFileName"); InputStream is = arg0.getIn().getBody(InputStream.class); BufferedReader br = new BufferedReader(new InputStreamReader(is); St

30、ring str = br.readLine(); while(str!=null) System.out.println(str); str = br.readLine(); ); from("jms:xmlOrders").process(new Processor() Override public void process(Exchange arg0) throws Exception 推荐精选 System.out.println("Recive xml order :" + arg0.getIn().getHeader("Camel

31、FileName"); ); ); context.start(); boolean loop =true; while(loop) Thread.sleep(9000); context.stop(); 5. 附加pom.xml <?xml version="1.0" encoding="UTF-8"?><project xmlns="/POM/4.0.0" xmlns:xsi="/2001/XMLSchema-inst

32、ance" xsi:schemaLocation="/POM/4.0.0 /maven-v4_0_0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.apache.camel</groupId><artifactId>examples</artifactId><version>2.14.0</vers

33、ion></parent><artifactId>camel-example-activemq-tomcat</artifactId><name>Camel : Example : ActiveMQ : Tomcat</name><description>An example using ActiveMQ Broker and Camel with Apache Tomcat</description><packaging>war</packaging><build>&

34、lt;plugins><plugin><groupId>org.codehaus.mojo</groupId><artifactId>tomcat-maven-plugin</artifactId><configuration><server>myTomcat</server><url>$tomcat.url</url><path>/$project.build.finalName</path></configuration><

35、/plugin><plugin><groupId>org.codehaus.mojo</groupId><artifactId>exec-maven-plugin</artifactId>推荐精选<configuration><mainClass>org.apache.camel.example.cxf.CamelRouteClient</mainClass><includePluginDependencies>false</includePluginDependencies

36、><systemProperties><property><key>java.util.logging.config.file</key><value>perties</value></property></systemProperties></configuration></plugin></plugins><!- Name of the generated WAR file -><finalName>came

37、l-example-activemq-tomcat</finalName></build><dependencies><!- camel -><dependency><groupId>org.apache.camel</groupId><artifactId>camel-core</artifactId></dependency><dependency><groupId>org.apache.camel</groupId><artif

38、actId>camel-spring</artifactId></dependency><dependency><groupId>org.apache.camel</groupId><artifactId>camel-stream</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifac

39、tId></dependency><!- camel jms and activemq -><dependency><groupId>org.apache.camel</groupId><artifactId>camel-jms</artifactId></dependency><dependency><groupId>org.apache.activemq</groupId><artifactId>activemq-camel</arti

40、factId></dependency><dependency><groupId>org.apache.activemq</groupId>推荐精选<artifactId>activemq-broker</artifactId></dependency><dependency><groupId>org.apache.activemq</groupId><artifactId>activemq-spring</artifactId></dep

41、endency><dependency><groupId>org.apache.activemq</groupId><artifactId>activemq-kahadb-store</artifactId></dependency><dependency><groupId>org.apache.activemq</groupId><artifactId>activemq-client</artifactId></dependency><d

42、ependency><groupId>org.apache.activemq</groupId><artifactId>activemq-pool</artifactId></dependency><!- xbean is required for ActiveMQ broker configuration in the spring xml file -><dependency><groupId>org.apache.xbean</groupId><artifactId&g

43、t;xbean-spring</artifactId></dependency><dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-quartz</artifactId></dependency><dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-http</artifactId>

44、;</dependency><dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-freemarker</artifactId></dependency><!- logging -><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId>推荐精选</dependency>&l

45、t;dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId></dependency></dependencies><profiles><profile><id>Tomcat7</id><activation><activeByDefault>true</activeByDefault></activation><pro

46、perties><tomcat.url>http:/localhost:8080/manager/text</tomcat.url></properties></profile><profile><id>Tomcat6</id><properties><tomcat.url>http:/localhost:8080/manager</tomcat.url></properties></profile></profiles></p

47、roject>二应用场景及项目应用 Enterprise Application Integration 企业应用集成(EAI)企业应用集成是必要的，几乎每家公司都有很多新产品及应用，如何集成这些应用程序是一个问题。来每十年诞生一个新范式，例如客户端/服务器通信，面向服务的架构（SOA）或云计算。此外，不同的接口或协议和技术的出现。过去数据存储在文件，SQL数据库在今天很通用。有时，还需要NoSQL数据库。同步远程过程调用RPC或异步消息是通过如RMI，SOAP的Web服务，REST或JMS进行通信的。很多软件筒仓还存在。Enterprise Integration Patterns 企业集成模式(EIP)当然，你可以推倒重来，然后再写一些意大利面条代码，让应用程序协同工作。不幸的是，你的管理者不会喜欢这个缺少长远眼光的解决方案。企业集成模式（）帮助碎片的问题，并使用标准化的方法来集成应用程序。使用相同的概念路由消息来改造。因此，每次有问题时重新发明轮子不是个好主意。推荐精选集成的替代方案解决方案1 ：自定义解决方案实现一个单独的解决方案，适用于您的问题还没有分离切成碎片。此工程可能是最快的替代的小型用例。你必须自己编写所有。维护成本可能会高，特别是如果团队成员改变。解决方案2：集成框架使用这类