diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/Runner.java b/android/TerminalApp/java/com/android/virtualization/terminal/Runner.java
deleted file mode 100644
index 4094025..0000000
--- a/android/TerminalApp/java/com/android/virtualization/terminal/Runner.java
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright (C) 2024 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.android.virtualization.terminal;
-
-import static com.android.virtualization.terminal.MainActivity.TAG;
-
-import android.content.Context;
-import android.system.virtualmachine.VirtualMachine;
-import android.system.virtualmachine.VirtualMachineCallback;
-import android.system.virtualmachine.VirtualMachineConfig;
-import android.system.virtualmachine.VirtualMachineCustomImageConfig;
-import android.system.virtualmachine.VirtualMachineException;
-import android.system.virtualmachine.VirtualMachineManager;
-import android.util.Log;
-
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ForkJoinPool;
-
-/** Utility class for creating a VM and waiting for it to finish. */
-class Runner {
-    private final VirtualMachine mVirtualMachine;
-    private final Callback mCallback;
-
-    private Runner(VirtualMachine vm, Callback cb) {
-        mVirtualMachine = vm;
-        mCallback = cb;
-    }
-
-    /** Create a virtual machine of the given config, under the given context. */
-    static Runner create(Context context, VirtualMachineConfig config)
-            throws VirtualMachineException {
-        // context may already be the app context, but calling this again is not harmful.
-        // See b/359439878 on why vmm should be obtained from the app context.
-        Context appContext = context.getApplicationContext();
-        VirtualMachineManager vmm = appContext.getSystemService(VirtualMachineManager.class);
-        VirtualMachineCustomImageConfig customConfig = config.getCustomImageConfig();
-        if (customConfig == null) {
-            throw new RuntimeException("CustomImageConfig is missing");
-        }
-
-        String name = customConfig.getName();
-        if (name == null || name.isEmpty()) {
-            throw new RuntimeException("Virtual machine's name is missing in the config");
-        }
-
-        VirtualMachine vm = vmm.getOrCreate(name, config);
-        try {
-            vm.setConfig(config);
-        } catch (VirtualMachineException e) {
-            vmm.delete(name);
-            vm = vmm.create(name, config);
-            Log.w(TAG, "Re-creating virtual machine (" + name + ")", e);
-        }
-
-        Callback cb = new Callback();
-        vm.setCallback(ForkJoinPool.commonPool(), cb);
-        vm.run();
-        return new Runner(vm, cb);
-    }
-
-    /** Give access to the underlying VirtualMachine object. */
-    VirtualMachine getVm() {
-        return mVirtualMachine;
-    }
-
-    /** Get future about VM's exit status. */
-    CompletableFuture<Boolean> getExitStatus() {
-        return mCallback.mFinishedSuccessfully;
-    }
-
-    private static class Callback implements VirtualMachineCallback {
-        final CompletableFuture<Boolean> mFinishedSuccessfully = new CompletableFuture<>();
-
-        @Override
-        public void onPayloadStarted(VirtualMachine vm) {
-            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
-        }
-
-        @Override
-        public void onPayloadReady(VirtualMachine vm) {
-            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
-        }
-
-        @Override
-        public void onPayloadFinished(VirtualMachine vm, int exitCode) {
-            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
-        }
-
-        @Override
-        public void onError(VirtualMachine vm, int errorCode, String message) {
-            Log.e(TAG, "Error from VM. code: " + errorCode + " (" + message + ")");
-            mFinishedSuccessfully.complete(false);
-        }
-
-        @Override
-        public void onStopped(VirtualMachine vm, int reason) {
-            Log.d(TAG, "VM stopped. Reason: " + reason);
-            mFinishedSuccessfully.complete(true);
-        }
-    }
-}
diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/Runner.kt b/android/TerminalApp/java/com/android/virtualization/terminal/Runner.kt
new file mode 100644
index 0000000..86dadbe
--- /dev/null
+++ b/android/TerminalApp/java/com/android/virtualization/terminal/Runner.kt
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2024 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.android.virtualization.terminal
+
+import android.content.Context
+import android.system.virtualmachine.VirtualMachine
+import android.system.virtualmachine.VirtualMachineCallback
+import android.system.virtualmachine.VirtualMachineConfig
+import android.system.virtualmachine.VirtualMachineException
+import android.system.virtualmachine.VirtualMachineManager
+import android.util.Log
+import com.android.virtualization.terminal.MainActivity.TAG
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.ForkJoinPool
+
+/** Utility class for creating a VM and waiting for it to finish. */
+internal class Runner private constructor(val vm: VirtualMachine?, callback: Callback) {
+    /** Get future about VM's exit status. */
+    val exitStatus = callback.finishedSuccessfully
+
+    private class Callback : VirtualMachineCallback {
+        val finishedSuccessfully: CompletableFuture<Boolean?> = CompletableFuture<Boolean?>()
+
+        override fun onPayloadStarted(vm: VirtualMachine) {
+            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
+        }
+
+        override fun onPayloadReady(vm: VirtualMachine) {
+            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
+        }
+
+        override fun onPayloadFinished(vm: VirtualMachine, exitCode: Int) {
+            // This event is only from Microdroid-based VM. Custom VM shouldn't emit this.
+        }
+
+        override fun onError(vm: VirtualMachine, errorCode: Int, message: String) {
+            Log.e(TAG, "Error from VM. code: $errorCode ($message)")
+            finishedSuccessfully.complete(false)
+        }
+
+        override fun onStopped(vm: VirtualMachine, reason: Int) {
+            Log.d(TAG, "VM stopped. Reason: $reason")
+            finishedSuccessfully.complete(true)
+        }
+    }
+
+    companion object {
+        /** Create a virtual machine of the given config, under the given context. */
+        @JvmStatic
+        @Throws(VirtualMachineException::class)
+        fun create(context: Context, config: VirtualMachineConfig): Runner {
+            // context may already be the app context, but calling this again is not harmful.
+            // See b/359439878 on why vmm should be obtained from the app context.
+            val appContext = context.getApplicationContext()
+            val vmm =
+                appContext.getSystemService<VirtualMachineManager>(
+                    VirtualMachineManager::class.java
+                )
+            val customConfig = config.customImageConfig
+            requireNotNull(customConfig) { "CustomImageConfig is missing" }
+
+            val name = customConfig.name
+            require(!name.isNullOrEmpty()) { "Virtual machine's name is missing in the config" }
+
+            var vm = vmm.getOrCreate(name, config)
+            try {
+                vm.config = config
+            } catch (e: VirtualMachineException) {
+                vmm.delete(name)
+                vm = vmm.create(name, config)
+                Log.w(TAG, "Re-creating virtual machine ($name)", e)
+            }
+
+            val cb = Callback()
+            vm.setCallback(ForkJoinPool.commonPool(), cb)
+            vm.run()
+            return Runner(vm, cb)
+        }
+    }
+}