Spring Boot集成Java DSL的实现代码

发布时间：2020-08-28 13:55:02 来源：脚本之家阅读：194 作者：banq 栏目：编程语言

Spring Integration Java DSL已经融合到Spring Integration Core 5.0，这是一个聪明而明显的举动，因为：

基于Java Config启动新Spring项目的每个人都使用它
SI Java DSL使您可以使用Lambdas等新的强大Java 8功能
您可以使用基于IntegrationFlowBuilder的Builder模式构建流

让我们看看基于ActiveMQ JMS的示例如何使用它。

Maven依赖：

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-activemq</artifactId>
  </dependency>

  <dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-core</artifactId>
  </dependency>

  <dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-jms</artifactId>
  </dependency>

  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
  </dependency>

  <dependency>
    <groupId>org.apache.activemq</groupId>
    <artifactId>activemq-kahadb-store</artifactId>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.springframework.integration/spring-integration-java-dsl -->
  <dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-java-dsl</artifactId>
    <version>1.2.3.RELEASE</version>
  </dependency>
</dependencies>

示例1：Jms入站网关

我们有以下ServiceActivator：

@Service
public class ActiveMQEndpoint {
  @ServiceActivator(inputChannel = "inboundChannel")
  public void processMessage(final String inboundPayload) {
    System.out.println("Inbound message: "+inboundPayload);
  }
}

如果您想使用SI Java DSL 将inboundPayload从Jms队列发送到Gateway风格的激活器，那么请使用DSLJms工厂：

@Bean
public DynamicDestinationResolver dynamicDestinationResolver() {
  return new DynamicDestinationResolver();
}

@Bean
public ActiveMQConnectionFactory connectionFactory() {
  return new ActiveMQConnectionFactory();
}

@Bean
public DefaultMessageListenerContainer listenerContainer() {
  final DefaultMessageListenerContainer defaultMessageListenerContainer = new DefaultMessageListenerContainer();
  defaultMessageListenerContainer.setDestinationResolver(dynamicDestinationResolver());
  defaultMessageListenerContainer.setConnectionFactory(connectionFactory());
  defaultMessageListenerContainer.setDestinationName("jms.activeMQ.Test");
  return defaultMessageListenerContainer;
}

@Bean
public MessageChannel inboundChannel() {
  return MessageChannels.direct("inboundChannel").get();
}

@Bean
public JmsInboundGateway dataEndpoint() {
  return Jms.inboundGateway(listenerContainer())
      .requestChannel(inboundChannel()).get();
}

通过dataEndpoint bean 返回JmsInboundGatewaySpec，您还可以向SI通道或Jms目标发送回复。查看文档。

示例2：Jms消息驱动的通道适配器

如果您正在寻找替换消息驱动通道适配器的XML JMS配置，那么JmsMessageDrivenChannelAdapter是一种适合您的方式：

@Bean
public DynamicDestinationResolver dynamicDestinationResolver() {
  return new DynamicDestinationResolver();
}

@Bean
public ActiveMQConnectionFactory connectionFactory() {
  return new ActiveMQConnectionFactory();
}

@Bean
public DefaultMessageListenerContainer listenerContainer() {
  final DefaultMessageListenerContainer defaultMessageListenerContainer = new DefaultMessageListenerContainer();
  defaultMessageListenerContainer.setDestinationResolver(dynamicDestinationResolver());
  defaultMessageListenerContainer.setConnectionFactory(connectionFactory());
  defaultMessageListenerContainer.setDestinationName("jms.activeMQ.Test");
  return defaultMessageListenerContainer;
}

@Bean
public MessageChannel inboundChannel() {
  return MessageChannels.direct("inboundChannel").get();
}

@Bean
public JmsMessageDrivenChannelAdapter dataEndpoint() {
  final ChannelPublishingJmsMessageListener channelPublishingJmsMessageListener =
      new ChannelPublishingJmsMessageListener();
  channelPublishingJmsMessageListener.setExpectReply(false);
  final JmsMessageDrivenChannelAdapter messageDrivenChannelAdapter = new
      JmsMessageDrivenChannelAdapter(listenerContainer(), channelPublishingJmsMessageListener
      );

  messageDrivenChannelAdapter.setOutputChannel(inboundChannel());
  return messageDrivenChannelAdapter;
}

与前面的示例一样，入站有效负载如样本1中一样发送给激活器。

示例3：使用JAXB的Jms消息驱动的通道适配器

在典型的场景中，您希望通过Jms接受XML作为文本消息，将其转换为JAXB存根并在服务激活器中处理它。我将向您展示如何使用SI Java DSL执行此操作，但首先让我们为xml处理添加两个依赖项：

<dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-xml</artifactId>
  </dependency>

  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-oxm</artifactId>
  </dependency>

我们将通过JMS接受shiporders ，所以首先XSD命名为shiporder.xsd：

<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:element name="shiporder">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="orderperson" type="xs:string"/>
        <xs:element name="shipto">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="name" type="xs:string"/>
              <xs:element name="address" type="xs:string"/>
              <xs:element name="city" type="xs:string"/>
              <xs:element name="country" type="xs:string"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
        <xs:element name="item" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="title" type="xs:string"/>
              <xs:element name="note" type="xs:string" minOccurs="0"/>
              <xs:element name="quantity" type="xs:positiveInteger"/>
              <xs:element name="price" type="xs:decimal"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
      <xs:attribute name="orderid" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>

</xs:schema>

新增JAXB maven plugin 生成JAXB存根：

 <plugin>
      <groupId>org.codehaus.mojo</groupId>
      <artifactId>jaxb2-maven-plugin</artifactId>
      <version>2.3.1</version>
      <executions>
        <execution>
          <id>xjc-schema1</id>
          <goals>
            <goal>xjc</goal>
          </goals>
          <configuration>
            <!-- Use all XSDs under the west directory for sources here. -->
            <sources>
              <source>src/main/resources/xsds/shiporder.xsd</source>
            </sources>

            <!-- Package name of the generated sources. -->
            <packageName>com.example.stubs</packageName>
            <outputDirectory>src/main/java</outputDirectory>
            <clearOutputDir>false</clearOutputDir>
          </configuration>
        </execution>
      </executions>
    </plugin>

我们已经准备好了存根类和一切，现在使用Jaxb magic的Java DSL JMS消息驱动适配器：

/**
 * Sample 3: Jms message driven adapter with JAXB
 */
@Bean
public JmsMessageDrivenChannelAdapter dataEndpoint() {
  final ChannelPublishingJmsMessageListener channelPublishingJmsMessageListener =
      new ChannelPublishingJmsMessageListener();
  channelPublishingJmsMessageListener.setExpectReply(false);
  channelPublishingJmsMessageListener.setMessageConverter(new MarshallingMessageConverter(shipOrdersMarshaller()));
  final JmsMessageDrivenChannelAdapter messageDrivenChannelAdapter = new
      JmsMessageDrivenChannelAdapter(listenerContainer(), channelPublishingJmsMessageListener
  );

  messageDrivenChannelAdapter.setOutputChannel(inboundChannel());
  return messageDrivenChannelAdapter;
}

@Bean
public Jaxb2Marshaller shipOrdersMarshaller() {
  Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
  marshaller.setContextPath("com.example.stubs");
  return marshaller;
}

XML配置在Java中使用它可以为您提供如此强大的功能和灵活性。要完成此示例，inboundChannel的服务激活器将如下所示：

/**
 * Sample 3
 * @param shiporder
 */
@ServiceActivator(inputChannel = "inboundChannel")
public void processMessage(final Shiporder shiporder) {
  System.out.println(shiporder.getOrderid());
  System.out.println(shiporder.getOrderperson());
}

要测试流，您可以使用以下XML通过JConsole发送到JMS队列：

 <?xml version="1.0" encoding="UTF-8"?>    
  <shiporder orderid="889923"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="shiporder.xsd">
   <orderperson>John Smith</orderperson>
    <shipto>
     <name>Ola Nordmann</name>
     <address>Langgt 23</address>
     <city>4000 Stavanger</city>
     <country>Norway</country>
    </shipto>
    <item>
     <title>Empire Burlesque</title>
     <note>Special Edition</note>
     <quantity>1</quantity>
     <price>10.90</price>
     </item>
    <item>
     <title>Hide your heart</title>
     <quantity>1</quantity>
     <price>9.90</price>
    </item>
  </shiporder>

示例4：具有JAXB和有效负载根路由的Jms消息驱动的通道适配器

另一种典型情况是接受XML作为JMS文本消息，将其转换为JAXB存根并根据有效负载根类型将有效负载路由到某个服务激活器。当然SI Java DSL支持所有类型的路由，我将向您展示如何根据有效载荷类型进行路由。

首先，将以下XSD添加到shiporder.xsd所在的文件夹中，并将其命名为purchaseorder.xsd：

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
      xmlns:tns="http://tempuri.org/PurchaseOrderSchema.xsd"
      targetNamespace="http://tempuri.org/PurchaseOrderSchema.xsd"
      elementFormDefault="qualified">
  <xsd:element name="PurchaseOrder">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="ShipTo" type="tns:USAddress" maxOccurs="2"/>
        <xsd:element name="BillTo" type="tns:USAddress"/>
      </xsd:sequence>
      <xsd:attribute name="OrderDate" type="xsd:date"/>
    </xsd:complexType>
  </xsd:element>

  <xsd:complexType name="USAddress">
    <xsd:sequence>
      <xsd:element name="name"  type="xsd:string"/>
      <xsd:element name="street" type="xsd:string"/>
      <xsd:element name="city"  type="xsd:string"/>
      <xsd:element name="state" type="xsd:string"/>
      <xsd:element name="zip"  type="xsd:integer"/>
    </xsd:sequence>
    <xsd:attribute name="country" type="xsd:NMTOKEN" fixed="US"/>
  </xsd:complexType>
</xsd:schema>

然后添加到jaxb maven插件配置：

 <plugin>
      <groupId>org.codehaus.mojo</groupId>
      <artifactId>jaxb2-maven-plugin</artifactId>
      <version>2.3.1</version>
      <executions>
        <execution>
          <id>xjc-schema1</id>
          <goals>
            <goal>xjc</goal>
          </goals>
          <configuration>
            <!-- Use all XSDs under the west directory for sources here. -->
            <sources>
              <source>src/main/resources/xsds/shiporder.xsd</source>
              <source>src/main/resources/xsds/purchaseorder.xsd</source>
            </sources>

            <!-- Package name of the generated sources. -->
            <packageName>com.example.stubs</packageName>
            <outputDirectory>src/main/java</outputDirectory>
            <clearOutputDir>false</clearOutputDir>
          </configuration>
        </execution>
      </executions>
    </plugin>

运行mvn clean install以生成新XSD的JAXB存根。现在承诺有效负载根映射：

@Bean
public Jaxb2Marshaller ordersMarshaller() {
  Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
  marshaller.setContextPath("com.example.stubs");
  return marshaller;
}

/**
 * Sample 4: Jms message driven adapter with Jaxb and Payload routing.
 * @return
 */
@Bean
public JmsMessageDrivenChannelAdapter dataEndpoint() {
  final ChannelPublishingJmsMessageListener channelPublishingJmsMessageListener =
      new ChannelPublishingJmsMessageListener();
  channelPublishingJmsMessageListener.setMessageConverter(new MarshallingMessageConverter(ordersMarshaller()));
  final JmsMessageDrivenChannelAdapter messageDrivenChannelAdapter = new
      JmsMessageDrivenChannelAdapter(listenerContainer(), channelPublishingJmsMessageListener
  );

  messageDrivenChannelAdapter.setOutputChannel(inboundChannel());
  return messageDrivenChannelAdapter;
}

@Bean
public IntegrationFlow payloadRootMapping() {
  return IntegrationFlows.from(inboundChannel()).<Object, Class<?>>route(Object::getClass, m->m
      .subFlowMapping(Shiporder.class, sf->sf.handle((MessageHandler) message -> {
        final Shiporder shiporder = (Shiporder) message.getPayload();
        System.out.println(shiporder.getOrderperson());
        System.out.println(shiporder.getOrderid());
      }))
      .subFlowMapping(PurchaseOrder.class, sf->sf.handle((MessageHandler) message -> {
        final PurchaseOrder purchaseOrderType = (PurchaseOrder) message.getPayload();
        System.out.println(purchaseOrderType.getBillTo().getName());
      }))
  ).get();
}

注意payloadRootMapping bean，让我们解释一下重要的部分：

<Object, Class<?>> route - 表示来自inboundChannel的输入将是Object，并且将根据Class <？>执行路由
subFlowMapping(Shiporder.class.. - ShipOders的处理。
subFlowMapping(PurchaseOrder.class ... - 处理PurchaseOrders。

要测试ShipOrder有效负载，请使用示例3中的XML，以测试PurchaseOrder有效负载，使用以下XML：

<?xml version="1.0" encoding="utf-8"?> 
<PurchaseOrder OrderDate="1900-01-01" xmlns="http://tempuri.org/PurchaseOrderSchema.xsd"> 
 <ShipTo country="US"> 
  <name>name1</name> 
  <street>street1</street> 
  <city>city1</city> 
  <state>state1</state> 
  <zip>1</zip> 
 </ShipTo> 
 <ShipTo country="US"> 
  <name>name2</name> 
  <street>street2</street> 
  <city>city2</city> 
  <state>state2</state> 
  <zip>-79228162514264337593543950335</zip> 
 </ShipTo> 
 <BillTo country="US"> 
  <name>name1</name> 
  <street>street1</street> 
  <city>city1</city> 
  <state>state1</state> 
  <zip>1</zip> 
 </BillTo> 
</PurchaseOrder>

应根据subflow 子流Map路由两个有效载荷。

示例5：IntegrationFlowAdapter

除了企业集成模式的其他实现（check them out)），我需要提到IntegrationFlowAdapter。通过扩展此类并实现buildFlow方法，如：

[url=https://bitbucket.org/Component/]@Component[/url] 
public class MyFlowAdapter extends IntegrationFlowAdapter {

@Autowired
 private ConnectionFactory rabbitConnectionFactory;

 @Override
 protected IntegrationFlowDefinition<?> buildFlow() {
   return from(Amqp.inboundAdapter(this.rabbitConnectionFactory, "myQueue"))
        .<String, String>transform(String::toLowerCase)
        .channel(c -> c.queue("myFlowAdapterOutput"));
 }

你可以将bean的重复声明包装成一个组件并给它们所需的流量。然后可以配置这样的组件并将其作为一个类实例提供给调用代码！

因此，让我们举例说明这个repo中的示例3更短一些，并为所有JmsEndpoints定义基类，并在其中定义重复bean：

public class JmsEndpoint extends IntegrationFlowAdapter {

  private String queueName;

  private String channelName;

  private String contextPath;

  /**
   * @param queueName
   * @param channelName
   * @param contextPath
   */
  public JmsEndpoint(String queueName, String channelName, String contextPath) {
    this.queueName = queueName;
    this.channelName = channelName;
    this.contextPath = contextPath;
  }

  @Override
  protected IntegrationFlowDefinition<?> buildFlow() {
    return from(Jms.messageDrivenChannelAdapter(listenerContainer())
      .jmsMessageConverter(new MarshallingMessageConverter(shipOrdersMarshaller()))
    ).channel(channelName);
  }

  @Bean
  public Jaxb2Marshaller shipOrdersMarshaller() {
    Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
    marshaller.setContextPath(contextPath);
    return marshaller;
  }

  @Bean
  public DynamicDestinationResolver dynamicDestinationResolver() {
    return new DynamicDestinationResolver();
  }

  @Bean
  public ActiveMQConnectionFactory connectionFactory() {
    return new ActiveMQConnectionFactory();
  }

  @Bean
  public DefaultMessageListenerContainer listenerContainer() {
    final DefaultMessageListenerContainer defaultMessageListenerContainer = new DefaultMessageListenerContainer();
    defaultMessageListenerContainer.setDestinationResolver(dynamicDestinationResolver());
    defaultMessageListenerContainer.setConnectionFactory(connectionFactory());
    defaultMessageListenerContainer.setDestinationName(queueName);
    return defaultMessageListenerContainer;
  }

  @Bean
  public MessageChannel inboundChannel() {
    return MessageChannels.direct(channelName).get();
  }
}

现在声明特定队列的Jms端点很容易：

@Bean
public JmsEndpoint jmsEndpoint() {
  return new JmsEndpoint("jms.activeMQ.Test", "inboundChannel", "com.example.stubs");
}

inboundChannel的服务激活器：

/**
 * Sample 3, 5
 * @param shiporder
 */
@ServiceActivator(inputChannel = "inboundChannel")
public void processMessage(final Shiporder shiporder) {
  System.out.println(shiporder.getOrderid());
  System.out.println(shiporder.getOrderperson());
}

您不应该错过在项目中使用IntegrationFlowAdapter。我喜欢它的概念。

我最近在Embedit的新的基于Spring Boot的项目中开始使用Spring Integration Java DSL 。即使有一些配置，我发现它非常有用。

它很容易调试。不添加像wiretap这样的配置。
阅读起来要容易得多。是的，即使是lambdas！
它很强大。在Java配置中，您现在有很多选择。

源码地址：https://bitbucket.org/tomask79/spring-integration-java-dsl

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持亿速云。

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