HDFS-16605. Improve Code With Lambda in hadoop-hdfs-rbf moudle. (#4375)

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/PeriodicService.java

@@ -167,21 +167,18 @@ public abstract class PeriodicService extends AbstractService {
     stopPeriodic();
 
     // Create the runnable service
-    Runnable updateRunnable = new Runnable() {
-      @Override
-      public void run() {
-        LOG.debug("Running {} update task", serviceName);
-        try {
-          if (!isRunning) {
-            return;
-          }
-          periodicInvoke();
-          runCount++;
-          lastRun = Time.now();
-        } catch (Exception ex) {
-          errorCount++;
-          LOG.warn(serviceName + " service threw an exception", ex);
+    Runnable updateRunnable = () -> {
+      LOG.debug("Running {} update task", serviceName);
+      try {
+        if (!isRunning) {
+          return;
         }
+        periodicInvoke();
+        runCount++;
+        lastRun = Time.now();
+      } catch (Exception ex) {
+        errorCount++;
+        LOG.warn("{} service threw an exception", serviceName, ex);
       }
     };
 

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterHeartbeatService.java

@@ -63,12 +63,7 @@ public class RouterHeartbeatService extends PeriodicService {
    * Trigger the update of the Router state asynchronously.
    */
   protected void updateStateAsync() {
-    Thread thread = new Thread(new Runnable() {
-      @Override
-      public void run() {
-        updateStateStore();
-      }
-    }, "Router Heartbeat Async");
+    Thread thread = new Thread(this::updateStateStore, "Router Heartbeat Async");
     thread.setDaemon(true);
     thread.start();
   }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcServer.java

@@ -405,7 +405,7 @@ public class RouterRpcServer extends AbstractService implements ClientProtocol,
                 .asMap()
                 .keySet()
                 .parallelStream()
-                .forEach((key) -> this.dnCache.refresh(key)),
+                .forEach(this.dnCache::refresh),
             0,
             dnCacheExpire, TimeUnit.MILLISECONDS);
     initRouterFedRename();

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/FederationTestUtils.java

@@ -92,8 +92,6 @@ import org.mockito.stubbing.Answer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.function.Supplier;
-
 /**
  * Helper utilities for testing HDFS Federation.
  */
@@ -174,26 +172,23 @@ public final class FederationTestUtils {
       final String nsId, final String nnId,
       final FederationNamenodeServiceState state) throws Exception {
 
-    GenericTestUtils.waitFor(new Supplier<Boolean>() {
-      @Override
-      public Boolean get() {
-        try {
-          List<? extends FederationNamenodeContext> namenodes =
-              resolver.getNamenodesForNameserviceId(nsId);
-          if (namenodes != null) {
-            for (FederationNamenodeContext namenode : namenodes) {
-              // Check if this is the Namenode we are checking
-              if (namenode.getNamenodeId() == nnId  ||
-                  namenode.getNamenodeId().equals(nnId)) {
-                return state == null || namenode.getState().equals(state);
-              }
+    GenericTestUtils.waitFor(() -> {
+      try {
+        List<? extends FederationNamenodeContext> namenodes =
+            resolver.getNamenodesForNameserviceId(nsId);
+        if (namenodes != null) {
+          for (FederationNamenodeContext namenode : namenodes) {
+            // Check if this is the Namenode we are checking
+            if (namenode.getNamenodeId() == nnId  ||
+                namenode.getNamenodeId().equals(nnId)) {
+              return state == null || namenode.getState().equals(state);
             }
           }
-        } catch (IOException e) {
-          // Ignore
         }
-        return false;
+      } catch (IOException e) {
+        // Ignore
       }
+      return false;
     }, 1000, 60 * 1000);
   }
 
@@ -209,22 +204,19 @@ public final class FederationTestUtils {
       final ActiveNamenodeResolver resolver, final String nsId,
       final FederationNamenodeServiceState state) throws Exception {
 
-    GenericTestUtils.waitFor(new Supplier<Boolean>() {
-      @Override
-      public Boolean get() {
-        try {
-          List<? extends FederationNamenodeContext> nns =
-              resolver.getNamenodesForNameserviceId(nsId);
-          for (FederationNamenodeContext nn : nns) {
-            if (nn.getState().equals(state)) {
-              return true;
-            }
+    GenericTestUtils.waitFor(() -> {
+      try {
+        List<? extends FederationNamenodeContext> nns =
+            resolver.getNamenodesForNameserviceId(nsId);
+        for (FederationNamenodeContext nn : nns) {
+          if (nn.getState().equals(state)) {
+            return true;
           }
-        } catch (IOException e) {
-          // Ignore
         }
-        return false;
+      } catch (IOException e) {
+        // Ignore
       }
+      return false;
     }, 1000, 20 * 1000);
   }
 
@@ -361,19 +353,16 @@ public final class FederationTestUtils {
    */
   public static void waitRouterRegistered(RouterStore stateManager,
       long routerCount, int timeout) throws Exception {
-    GenericTestUtils.waitFor(new Supplier<Boolean>() {
-      @Override
-      public Boolean get() {
-        try {
-          List<RouterState> cachedRecords = stateManager.getCachedRecords();
-          if (cachedRecords.size() == routerCount) {
-            return true;
-          }
-        } catch (IOException e) {
-          // Ignore
+    GenericTestUtils.waitFor(() -> {
+      try {
+        List<RouterState> cachedRecords = stateManager.getCachedRecords();
+        if (cachedRecords.size() == routerCount) {
+          return true;
         }
-        return false;
+      } catch (IOException e) {
+        // Ignore
       }
+      return false;
     }, 100, timeout);
   }
 
@@ -390,13 +379,10 @@ public final class FederationTestUtils {
     ConnectionManager connectionManager =
         new ConnectionManager(server.getConfig());
     ConnectionManager spyConnectionManager = spy(connectionManager);
-    doAnswer(new Answer() {
-      @Override
-      public Object answer(InvocationOnMock invocation) throws Throwable {
-        LOG.info("Simulating connectionManager throw IOException {}",
-            invocation.getMock());
-        throw new IOException("Simulate connectionManager throw IOException");
-      }
+    doAnswer(invocation -> {
+      LOG.info("Simulating connectionManager throw IOException {}",
+          invocation.getMock());
+      throw new IOException("Simulate connectionManager throw IOException");
     }).when(spyConnectionManager).getConnection(
         any(UserGroupInformation.class), any(String.class), any(Class.class));
 

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/MiniRouterDFSCluster.java

@@ -237,12 +237,8 @@ public class MiniRouterDFSCluster {
         throws IOException, URISyntaxException, InterruptedException {
 
       LOG.info("Connecting to router at {}", fileSystemUri);
-      return user.doAs(new PrivilegedExceptionAction<DFSClient>() {
-        @Override
-        public DFSClient run() throws IOException {
-          return new DFSClient(fileSystemUri, conf);
-        }
-      });
+      return user.doAs((PrivilegedExceptionAction<DFSClient>)
+          () -> new DFSClient(fileSystemUri, conf));
     }
 
     public RouterClient getAdminClient() throws IOException {
@@ -384,12 +380,8 @@ public class MiniRouterDFSCluster {
         throws IOException, URISyntaxException, InterruptedException {
 
       LOG.info("Connecting to namenode at {}", fileSystemUri);
-      return user.doAs(new PrivilegedExceptionAction<DFSClient>() {
-        @Override
-        public DFSClient run() throws IOException {
-          return new DFSClient(fileSystemUri, conf);
-        }
-      });
+      return user.doAs((PrivilegedExceptionAction<DFSClient>)
+          () -> new DFSClient(fileSystemUri, conf));
     }
 
     public DFSClient getClient() throws IOException, URISyntaxException {

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/MockNamenode.java

@@ -156,15 +156,12 @@ public class MockNamenode {
     NamespaceInfo nsInfo = new NamespaceInfo(1, this.nsId, this.nsId, 1);
     when(mockNn.versionRequest()).thenReturn(nsInfo);
 
-    when(mockNn.getServiceStatus()).thenAnswer(new Answer<HAServiceStatus>() {
-      @Override
-      public HAServiceStatus answer(InvocationOnMock invocation)
-          throws Throwable {
-        HAServiceStatus haStatus = new HAServiceStatus(getHAServiceState());
-        haStatus.setNotReadyToBecomeActive("");
-        return haStatus;
-      }
-    });
+    when(mockNn.getServiceStatus()).
+        thenAnswer((Answer<HAServiceStatus>) invocation -> {
+          HAServiceStatus haStatus = new HAServiceStatus(getHAServiceState());
+          haStatus.setNotReadyToBecomeActive("");
+          return haStatus;
+        });
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/fairness/TestRouterRefreshFairnessPolicyController.java

@@ -133,9 +133,8 @@ public class TestRouterRefreshFairnessPolicyController {
     // Spawn 100 concurrent refresh requests
     Thread[] threads = new Thread[100];
     for (int i = 0; i < 100; i++) {
-      threads[i] = new Thread(() -> {
-        client.refreshFairnessPolicyController(routerContext.getConf());
-      });
+      threads[i] = new Thread(() ->
+          client.refreshFairnessPolicyController(routerContext.getConf()));
     }
 
     for (Thread thread : threads) {
@@ -182,9 +181,8 @@ public class TestRouterRefreshFairnessPolicyController {
     final int newNs1Permits = 4;
     conf.setInt(DFS_ROUTER_FAIR_HANDLER_COUNT_KEY_PREFIX + "ns0", newNs0Permits);
     conf.setInt(DFS_ROUTER_FAIR_HANDLER_COUNT_KEY_PREFIX + "ns1", newNs1Permits);
-    Thread threadRefreshController = new Thread(() -> {
-      client.refreshFairnessPolicyController(routerContext.getConf());
-    });
+    Thread threadRefreshController = new Thread(() -> client.
+        refreshFairnessPolicyController(routerContext.getConf()));
     threadRefreshController.start();
     threadRefreshController.join();
 

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/resolver/order/TestLocalResolver.java

@@ -43,7 +43,6 @@ import org.apache.hadoop.hdfs.server.federation.store.protocol.GetNamenodeRegist
 import org.apache.hadoop.hdfs.server.federation.store.records.MembershipState;
 import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
 import org.junit.Test;
-import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 
 /**
@@ -78,12 +77,8 @@ public class TestLocalResolver {
     StringBuilder sb = new StringBuilder("clientX");
     LocalResolver localResolver = new LocalResolver(conf, router);
     LocalResolver spyLocalResolver = spy(localResolver);
-    doAnswer(new Answer<String>() {
-      @Override
-      public String answer(InvocationOnMock invocation) throws Throwable {
-        return sb.toString();
-      }
-    }).when(spyLocalResolver).getClientAddr();
+    doAnswer((Answer<String>) invocation -> sb.toString()
+        ).when(spyLocalResolver).getClientAddr();
 
     // Add the mocks to the resolver
     MultipleDestinationMountTableResolver resolver =

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestConnectionManager.java

@@ -144,7 +144,7 @@ public class TestConnectionManager {
     connectionCreator.setDaemon(true);
     connectionCreator.start();
     // Wait to make sure async thread is scheduled and picks
-    GenericTestUtils.waitFor(()->queue.isEmpty(), 50, 5000);
+    GenericTestUtils.waitFor(queue::isEmpty, 50, 5000);
     // At this point connection creation task should be definitely picked up.
     assertTrue(queue.isEmpty());
     // At this point connection thread should still be alive.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterClientRejectOverload.java

@@ -206,33 +206,29 @@ public class TestRouterClientRejectOverload {
     for (int i = 0; i < numOps; i++) {
       // Stagger the operations a little (50ms)
       final int sleepTime = i * 50;
-      Future<?> future = exec.submit(new Runnable() {
-        @Override
-        public void run() {
-          DFSClient routerClient = null;
-          try {
-            Thread.sleep(sleepTime);
-            routerClient = new DFSClient(address, conf);
-            String clientName = routerClient.getClientName();
-            ClientProtocol routerProto = routerClient.getNamenode();
-            routerProto.renewLease(clientName, null);
-          } catch (RemoteException re) {
-            IOException ioe = re.unwrapRemoteException();
-            assertTrue("Wrong exception: " + ioe,
-                ioe instanceof StandbyException);
-            assertExceptionContains("is overloaded", ioe);
-            overloadException.incrementAndGet();
-          } catch (IOException e) {
-            fail("Unexpected exception: " + e);
-          } catch (InterruptedException e) {
-            fail("Cannot sleep: " + e);
-          } finally {
-            if (routerClient != null) {
-              try {
-                routerClient.close();
-              } catch (IOException e) {
-                LOG.error("Cannot close the client");
-              }
+      Future<?> future = exec.submit(() -> {
+        DFSClient routerClient = null;
+        try {
+          Thread.sleep(sleepTime);
+          routerClient = new DFSClient(address, conf);
+          String clientName = routerClient.getClientName();
+          ClientProtocol routerProto = routerClient.getNamenode();
+          routerProto.renewLease(clientName, null);
+        } catch (RemoteException re) {
+          IOException ioe = re.unwrapRemoteException();
+          assertTrue("Wrong exception: " + ioe, ioe instanceof StandbyException);
+          assertExceptionContains("is overloaded", ioe);
+          overloadException.incrementAndGet();
+        } catch (IOException e) {
+          fail("Unexpected exception: " + e);
+        } catch (InterruptedException e) {
+          fail("Cannot sleep: " + e);
+        } finally {
+          if (routerClient != null) {
+            try {
+              routerClient.close();
+            } catch (IOException e) {
+              LOG.error("Cannot close the client");
             }
           }
         }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterFaultTolerant.java

@@ -168,7 +168,7 @@ public class TestRouterFaultTolerant {
     }
     namenodes.clear();
 
-    routers.forEach(router ->  router.stop());
+    routers.forEach(Router::stop);
     routers.clear();
 
     if (service != null) {

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterQuota.java

@@ -74,8 +74,6 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.function.Supplier;
-
 /**
  * Tests quota behaviors in Router-based Federation.
  */
@@ -210,21 +208,17 @@ public class TestRouterQuota {
     routerClient.create("/ssquota/file", true).close();
     routerClient.create("/ssquota/subdir/file", true).close();
 
-    GenericTestUtils.waitFor(new Supplier<Boolean>() {
-
-      @Override
-      public Boolean get() {
-        boolean isDsQuotaViolated = false;
-        try {
-          // append data to trigger NSQuotaExceededException
-          appendData("/ssquota/file", routerClient, BLOCK_SIZE);
-          appendData("/ssquota/subdir/file", routerClient, BLOCK_SIZE);
-        } catch (DSQuotaExceededException e) {
-          isDsQuotaViolated = true;
-        } catch (IOException ignored) {
-        }
-        return isDsQuotaViolated;
+    GenericTestUtils.waitFor(() -> {
+      boolean isDsQuotaViolated = false;
+      try {
+        // append data to trigger NSQuotaExceededException
+        appendData("/ssquota/file", routerClient, BLOCK_SIZE);
+        appendData("/ssquota/subdir/file", routerClient, BLOCK_SIZE);
+      } catch (DSQuotaExceededException e) {
+        isDsQuotaViolated = true;
+      } catch (IOException ignored) {
       }
+      return isDsQuotaViolated;
     }, 5000, 60000);
 
     // append data to destination path in real FileSystem should be okay

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRPCClientRetries.java

@@ -54,8 +54,6 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.Timeout;
 
-import java.util.function.Supplier;
-
 /**
  * Test retry behavior of the Router RPC Client.
  */
@@ -237,11 +235,6 @@ public class TestRouterRPCClientRetries {
   private static void waitUpdateLiveNodes(
       final String oldValue, final NamenodeBeanMetrics metrics)
           throws Exception {
-    waitFor(new Supplier<Boolean>() {
-      @Override
-      public Boolean get() {
-        return !oldValue.equals(metrics.getLiveNodes());
-      }
-    }, 500, 5 * 1000);
+    waitFor(() -> !oldValue.equals(metrics.getLiveNodes()), 500, 5 * 1000);
   }
 }