Merge pull request #1053 from corda/kit-getServiceOf

Extending NetwokMapCache with a convenience method for by type servic…

core/src/main/kotlin/net/corda/core/node/services/NetworkMapCache.kt

@@ -119,6 +119,20 @@ interface NetworkMapCache {
         return nodes.randomOrNull()?.notaryIdentity
     }
 
+    /**
+     * Returns a service identity advertised by one of the nodes on the network
+     * @param type Specifies the type of the service
+     */
+    fun getAnyServiceOfType(type: ServiceType): Party? {
+        for (node in partyNodes) {
+            val serviceIdentities = node.serviceIdentities(type)
+            if (serviceIdentities.isNotEmpty()) {
+                return serviceIdentities.randomOrNull()
+            }
+        }
+        return null;
+    }
+
     /** Checks whether a given party is an advertised notary identity */
     fun isNotary(party: Party): Boolean = notaryNodes.any { it.notaryIdentity == party }
 

node/src/integration-test/kotlin/net/corda/node/services/AdvertisedServiceTests.kt

@@ -0,0 +1,42 @@
+package net.corda.node.services
+
+import co.paralleluniverse.fibers.Suspendable
+import net.corda.core.flows.FlowLogic
+import net.corda.core.flows.StartableByRPC
+import net.corda.core.messaging.startFlow
+import net.corda.core.node.services.ServiceInfo
+import net.corda.core.node.services.ServiceType
+import net.corda.nodeapi.User
+import net.corda.testing.driver.driver
+import org.bouncycastle.asn1.x500.X500Name
+import org.junit.Test
+import kotlin.test.assertTrue
+
+class AdvertisedServiceTests {
+    private val serviceName = X500Name("CN=Custom Service,O=R3,OU=corda,L=London,C=GB")
+    private val serviceType = ServiceType.corda.getSubType("custom")
+    private val user = "bankA"
+    private val pass = "passA"
+
+
+    @StartableByRPC
+    class ServiceTypeCheckingFlow : FlowLogic<Boolean>() {
+
+        @Suspendable
+        override fun call(): Boolean {
+            return serviceHub.networkMapCache.getAnyServiceOfType(ServiceType.corda.getSubType("custom")) != null;
+        }
+    }
+
+    @Test
+    fun `service is accessible through getAnyServiceOfType`() {
+        driver(startNodesInProcess = true) {
+            val bankA = startNode(rpcUsers = listOf(User(user, pass, setOf(startFlowPermission<ServiceTypeCheckingFlow>())))).get()
+            val bankB = startNode(advertisedServices = setOf(ServiceInfo(serviceType, serviceName))).get()
+            bankA.rpcClientToNode().use(user, pass) { connection ->
+                val result = connection.proxy.startFlow(::ServiceTypeCheckingFlow).returnValue.get()
+                assertTrue(result)
+            }
+        }
+    }
+}