Wire Tap EIP implementation and tests

eip-wire-tap/src/main/java/com/iluwatar/eip/wiretap/App.java

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+package com.iluwatar.eip.wiretap;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * In most integration cases there is a need to monitor the messages flowing through the system. It is usually achieved
+ * by intercepting the message and redirecting it to a different location like console, filesystem or the database.
+ * It is important that such functionality should not modify the original message and influence the processing path.
+ *
+ * <p>
+ * Wire Tap allows you to route messages to a separate location while they are being forwarded to the ultimate
+ * destination. It basically consumes messages of the input channel and publishes the unmodified message to both
+ * output channels.
+ * </p>
+ */
+@SpringBootApplication
+public class App {
+
+  /**
+   * Program entry point. It starts Spring Boot application and using Apache Camel it auto-configures routes.
+   *
+   * @param args command line args
+   */
+  public static void main(String[] args) {
+    SpringApplication.run(App.class, args);
+  }
+}

eip-wire-tap/src/main/java/com/iluwatar/eip/wiretap/routes/WireTapRoute.java

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+package com.iluwatar.eip.wiretap.routes;
+
+import org.apache.camel.builder.RouteBuilder;
+import org.springframework.stereotype.Component;
+
+/**
+ * Sample wire tap route definition.
+ *
+ * <p>
+ * It consumes messages out of the <i>direct:entry</i> entry point and forwards them to <i>direct:endpoint</i>.
+ * Wire Tap intercepts the message and sends it to <i>direct:wireTap</i>, which in turn forwards it to
+ * <i>direct:wireTapEndpoint</i>.
+ * </p>
+ *
+ * In this example input/output endpoints names are stored in <i>application.properties</i> file.
+ */
+@Component
+public class WireTapRoute extends RouteBuilder {
+
+  /**
+   * Configures the route
+   * @throws Exception in case of exception during configuration
+   */
+  @Override
+  public void configure() throws Exception {
+    // Main route
+    from("{{entry}}").wireTap("direct:wireTap").to("{{endpoint}}");
+
+    // Wire tap route
+    from("direct:wireTap").to("{{wireTapEndpoint}}");
+  }
+}

eip-wire-tap/src/main/resources/application.properties

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+entry=direct:entry
+endpoint=direct:endpoint
+wireTapEndpoint=direct:wireTapEndpoint

eip-wire-tap/src/test/java/com/iluwatar/eip/wiretap/WireTapRouteTest.java

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+package com.iluwatar.eip.wiretap;
+
+import org.apache.camel.EndpointInject;
+import org.apache.camel.Message;
+import org.apache.camel.ProducerTemplate;
+import org.apache.camel.component.mock.MockEndpoint;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Test class for <i>WireTapRoute</i>.
+ * <p>
+ * In order for it to work we have to mock endpoints we want to read/write to. To mock those we need to substitute
+ * original endpoint names to mocks.
+ * </p>
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = WireTapRouteTest.class)
+@ActiveProfiles("test")
+@EnableAutoConfiguration
+@ComponentScan
+public class WireTapRouteTest {
+
+  @EndpointInject(uri = "{{entry}}")
+  private ProducerTemplate entry;
+
+  @EndpointInject(uri = "{{endpoint}}")
+  private MockEndpoint endpoint;
+
+  @EndpointInject(uri = "{{wireTapEndpoint}}")
+  private MockEndpoint wireTapEndpoint;
+
+  /**
+   * Test if both endpoints receive exactly one message containing the same, unchanged body.
+   * @throws Exception in case of en exception during the test
+   */
+  @Test
+  @DirtiesContext
+  public void testWireTap() throws Exception {
+    entry.sendBody("TEST");
+
+    endpoint.expectedMessageCount(1);
+    wireTapEndpoint.expectedMessageCount(1);
+
+    endpoint.assertIsSatisfied();
+    wireTapEndpoint.assertIsSatisfied();
+
+    Message endpointIn = endpoint.getExchanges().get(0).getIn();
+    Message wireTapEndpointIn = wireTapEndpoint.getExchanges().get(0).getIn();
+
+    assertEquals("TEST", endpointIn.getBody());
+    assertEquals("TEST", wireTapEndpointIn.getBody());
+  }
+}

eip-wire-tap/src/test/resources/application-test.properties

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+entry=direct:entry
+endpoint=mock:endpoint
+wireTapEndpoint=mock:wireTapEndpoint