[Thread] join/leave the network only once to save time in BorderRoutingTest

This can save around 10 seconds per test case.

Bug: 376423433
Change-Id: I7c61d03a57c06ff391b6486ac4e9b201adf67483
diff --git a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
index 1a2ff06..f022187 100644
--- a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
+++ b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
@@ -18,8 +18,9 @@
 
 import static android.Manifest.permission.MANAGE_TEST_NETWORKS;
 import static android.net.InetAddresses.parseNumericAddress;
-import static android.net.thread.utils.IntegrationTestUtils.DEFAULT_DATASET;
 import static android.net.thread.utils.IntegrationTestUtils.buildIcmpv4EchoReply;
+import static android.net.thread.utils.IntegrationTestUtils.DEFAULT_DATASET;
+import static android.net.thread.utils.IntegrationTestUtils.enableThreadAndJoinNetwork;
 import static android.net.thread.utils.IntegrationTestUtils.getIpv6LinkAddresses;
 import static android.net.thread.utils.IntegrationTestUtils.isExpectedIcmpv4Packet;
 import static android.net.thread.utils.IntegrationTestUtils.isExpectedIcmpv6Packet;
@@ -27,6 +28,7 @@
 import static android.net.thread.utils.IntegrationTestUtils.isInMulticastGroup;
 import static android.net.thread.utils.IntegrationTestUtils.isTo;
 import static android.net.thread.utils.IntegrationTestUtils.joinNetworkAndWaitForOmr;
+import static android.net.thread.utils.IntegrationTestUtils.leaveNetworkAndDisableThread;
 import static android.net.thread.utils.IntegrationTestUtils.newPacketReader;
 import static android.net.thread.utils.IntegrationTestUtils.pollForPacket;
 import static android.net.thread.utils.IntegrationTestUtils.sendUdpMessage;
@@ -73,7 +75,9 @@
 import com.android.testutils.TestNetworkTracker;
 
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
@@ -116,7 +120,7 @@
     private final Context mContext = ApplicationProvider.getApplicationContext();
     private final ThreadNetworkControllerWrapper mController =
             ThreadNetworkControllerWrapper.newInstance(mContext);
-    private OtDaemonController mOtCtl;
+    private final OtDaemonController mOtCtl = new OtDaemonController();
     private HandlerThread mHandlerThread;
     private Handler mHandler;
     private TestNetworkTracker mInfraNetworkTracker;
@@ -124,20 +128,24 @@
     private PollPacketReader mInfraNetworkReader;
     private InfraNetworkDevice mInfraDevice;
 
+    @BeforeClass
+    public static void beforeClass() throws Exception {
+        enableThreadAndJoinNetwork(DEFAULT_DATASET);
+    }
+
+    @AfterClass
+    public static void afterClass() throws Exception {
+        leaveNetworkAndDisableThread();
+    }
+
     @Before
     public void setUp() throws Exception {
-        // TODO: b/323301831 - This is a workaround to avoid unnecessary delay to re-form a network
-        mOtCtl = new OtDaemonController();
-        mOtCtl.factoryReset();
-
         mHandlerThread = new HandlerThread(getClass().getSimpleName());
         mHandlerThread.start();
         mHandler = new Handler(mHandlerThread.getLooper());
         mFtds = new ArrayList<>();
 
         setUpInfraNetwork();
-        mController.setEnabledAndWait(true);
-        mController.joinAndWait(DEFAULT_DATASET);
 
         // Creates a infra network device.
         mInfraNetworkReader = newPacketReader(mInfraNetworkTracker.getTestIface(), mHandler);
@@ -152,8 +160,6 @@
     @After
     public void tearDown() throws Exception {
         mController.setTestNetworkAsUpstreamAndWait(null);
-        mController.leaveAndWait();
-        tearDownInfraNetwork();
 
         mHandlerThread.quitSafely();
         mHandlerThread.join();
diff --git a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
index dc2a9c9..c3859c1 100644
--- a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
+++ b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
@@ -590,6 +590,27 @@
         return ftd.omrAddress
     }
 
+    /** Enables Thread and joins the specified Thread network. */
+    @JvmStatic
+    fun enableThreadAndJoinNetwork(dataset: ActiveOperationalDataset) {
+        // TODO: b/323301831 - This is a workaround to avoid unnecessary delay to re-form a network
+        OtDaemonController().factoryReset();
+
+        val context: Context = requireNotNull(ApplicationProvider.getApplicationContext());
+        val controller = requireNotNull(ThreadNetworkControllerWrapper.newInstance(context));
+        controller.setEnabledAndWait(true);
+        controller.joinAndWait(dataset);
+    }
+
+    /** Leaves the Thread network and disables Thread. */
+    @JvmStatic
+    fun leaveNetworkAndDisableThread() {
+        val context: Context = requireNotNull(ApplicationProvider.getApplicationContext());
+        val controller = requireNotNull(ThreadNetworkControllerWrapper.newInstance(context));
+        controller.leaveAndWait();
+        controller.setEnabledAndWait(false);
+    }
+
     private open class DefaultDiscoveryListener : NsdManager.DiscoveryListener {
         override fun onStartDiscoveryFailed(serviceType: String, errorCode: Int) {}
         override fun onStopDiscoveryFailed(serviceType: String, errorCode: Int) {}