diff --git a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanFactory.java b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanFactory.java
new file mode 100644
index 0000000..9befe16a
--- /dev/null
+++ b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanFactory.java
@@ -0,0 +1,49 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.metrics.proc;
+
+import com.google.common.flogger.FluentLogger;
+import com.sun.management.UnixOperatingSystemMXBean;
+import java.lang.management.ManagementFactory;
+import java.lang.management.OperatingSystemMXBean;
+import java.util.Arrays;
+
+@SuppressWarnings("restriction")
+class OperatingSystemMXBeanFactory {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  static OperatingSystemMXBeanInterface create() {
+    OperatingSystemMXBean sys = ManagementFactory.getOperatingSystemMXBean();
+    if (sys instanceof UnixOperatingSystemMXBean) {
+      return new OperatingSystemMXBeanUnixNative((UnixOperatingSystemMXBean) sys);
+    }
+
+    for (String name :
+        Arrays.asList(
+            "com.sun.management.UnixOperatingSystemMXBean",
+            "com.ibm.lang.management.UnixOperatingSystemMXBean")) {
+      try {
+        Class<?> impl = Class.forName(name);
+        if (impl.isInstance(sys)) {
+          return new OperatingSystemMXBeanReflectionBased(sys);
+        }
+      } catch (ReflectiveOperationException e) {
+        logger.atFine().withCause(e).log("No implementation for %s", name);
+      }
+    }
+    logger.atWarning().log("No implementation of UnixOperatingSystemMXBean found");
+    return null;
+  }
+}
diff --git a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanInterface.java b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanInterface.java
new file mode 100644
index 0000000..b7d6ebf
--- /dev/null
+++ b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanInterface.java
@@ -0,0 +1,21 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.metrics.proc;
+
+interface OperatingSystemMXBeanInterface {
+  long getProcessCpuTime();
+
+  long getOpenFileDescriptorCount();
+}
diff --git a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanProvider.java b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanProvider.java
deleted file mode 100644
index 10d589a..0000000
--- a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanProvider.java
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright (C) 2017 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.gerrit.metrics.proc;
-
-import com.google.common.flogger.FluentLogger;
-import java.lang.management.ManagementFactory;
-import java.lang.management.OperatingSystemMXBean;
-import java.lang.reflect.Method;
-import java.util.Arrays;
-
-class OperatingSystemMXBeanProvider {
-  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
-
-  private final OperatingSystemMXBean sys;
-  private final Method getProcessCpuTime;
-  private final Method getOpenFileDescriptorCount;
-
-  static class Factory {
-    static OperatingSystemMXBeanProvider create() {
-      OperatingSystemMXBean sys = ManagementFactory.getOperatingSystemMXBean();
-      for (String name :
-          Arrays.asList(
-              "com.sun.management.UnixOperatingSystemMXBean",
-              "com.ibm.lang.management.UnixOperatingSystemMXBean")) {
-        try {
-          Class<?> impl = Class.forName(name);
-          if (impl.isInstance(sys)) {
-            return new OperatingSystemMXBeanProvider(sys);
-          }
-        } catch (ReflectiveOperationException e) {
-          logger.atFine().withCause(e).log("No implementation for %s", name);
-        }
-      }
-      logger.atWarning().log("No implementation of UnixOperatingSystemMXBean found");
-      return null;
-    }
-  }
-
-  private OperatingSystemMXBeanProvider(OperatingSystemMXBean sys)
-      throws ReflectiveOperationException {
-    this.sys = sys;
-    getProcessCpuTime = sys.getClass().getMethod("getProcessCpuTime", new Class<?>[] {});
-    getProcessCpuTime.setAccessible(true);
-    getOpenFileDescriptorCount =
-        sys.getClass().getMethod("getOpenFileDescriptorCount", new Class<?>[] {});
-    getOpenFileDescriptorCount.setAccessible(true);
-  }
-
-  public long getProcessCpuTime() {
-    try {
-      return (long) getProcessCpuTime.invoke(sys, new Object[] {});
-    } catch (ReflectiveOperationException e) {
-      return -1;
-    }
-  }
-
-  public long getOpenFileDescriptorCount() {
-    try {
-      return (long) getOpenFileDescriptorCount.invoke(sys, new Object[] {});
-    } catch (ReflectiveOperationException e) {
-      return -1;
-    }
-  }
-}
diff --git a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanReflectionBased.java b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanReflectionBased.java
new file mode 100644
index 0000000..8dc54ab
--- /dev/null
+++ b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanReflectionBased.java
@@ -0,0 +1,51 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.metrics.proc;
+
+import java.lang.management.OperatingSystemMXBean;
+import java.lang.reflect.Method;
+
+class OperatingSystemMXBeanReflectionBased implements OperatingSystemMXBeanInterface {
+  private final OperatingSystemMXBean sys;
+  private final Method getProcessCpuTime;
+  private final Method getOpenFileDescriptorCount;
+
+  OperatingSystemMXBeanReflectionBased(OperatingSystemMXBean sys)
+      throws ReflectiveOperationException {
+    this.sys = sys;
+    getProcessCpuTime = sys.getClass().getMethod("getProcessCpuTime");
+    getProcessCpuTime.setAccessible(true);
+    getOpenFileDescriptorCount = sys.getClass().getMethod("getOpenFileDescriptorCount");
+    getOpenFileDescriptorCount.setAccessible(true);
+  }
+
+  @Override
+  public long getProcessCpuTime() {
+    try {
+      return (long) getProcessCpuTime.invoke(sys, new Object[] {});
+    } catch (ReflectiveOperationException e) {
+      return -1;
+    }
+  }
+
+  @Override
+  public long getOpenFileDescriptorCount() {
+    try {
+      return (long) getOpenFileDescriptorCount.invoke(sys, new Object[] {});
+    } catch (ReflectiveOperationException e) {
+      return -1;
+    }
+  }
+}
diff --git a/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanUnixNative.java b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanUnixNative.java
new file mode 100644
index 0000000..a7f5bba
--- /dev/null
+++ b/java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanUnixNative.java
@@ -0,0 +1,36 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.metrics.proc;
+
+import com.sun.management.UnixOperatingSystemMXBean;
+
+@SuppressWarnings("restriction")
+class OperatingSystemMXBeanUnixNative implements OperatingSystemMXBeanInterface {
+  private final UnixOperatingSystemMXBean sys;
+
+  OperatingSystemMXBeanUnixNative(UnixOperatingSystemMXBean sys) {
+    this.sys = sys;
+  }
+
+  @Override
+  public long getProcessCpuTime() {
+    return sys.getProcessCpuTime();
+  }
+
+  @Override
+  public long getOpenFileDescriptorCount() {
+    return sys.getOpenFileDescriptorCount();
+  }
+}
diff --git a/java/com/google/gerrit/metrics/proc/ProcMetricModule.java b/java/com/google/gerrit/metrics/proc/ProcMetricModule.java
index 6b9176b..5af2672 100644
--- a/java/com/google/gerrit/metrics/proc/ProcMetricModule.java
+++ b/java/com/google/gerrit/metrics/proc/ProcMetricModule.java
@@ -64,7 +64,7 @@
   }
 
   private void procCpuUsage(MetricMaker metrics) {
-    final OperatingSystemMXBeanProvider provider = OperatingSystemMXBeanProvider.Factory.create();
+    OperatingSystemMXBeanInterface provider = OperatingSystemMXBeanFactory.create();
 
     if (provider == null) {
       return;