Move IoUtils#deleteContents from CorePlatformApi set to framework

As a part of internal core libraries cleanup move usages of
IoUtils#deleteContents from CorePlatformApi set to framework.

Bug: 154796679
Test: m update-api
Merged-In: If7037029026b6753ab64be09aa52c40e04d5c7b1
Change-Id: If7037029026b6753ab64be09aa52c40e04d5c7b1

core/tests/utiltests/src/com/android/internal/util/FileRotatorTest.java

@@ -29,6 +29,8 @@ import android.util.Log;
 
 import com.android.internal.util.FileRotator.Reader;
 import com.android.internal.util.FileRotator.Writer;
+import com.android.internal.util.test.FsUtil;
+
 import com.google.android.collect.Lists;
 
 import java.io.DataInputStream;
@@ -38,15 +40,10 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.net.ProtocolException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Random;
 
-import junit.framework.Assert;
-
-import libcore.io.IoUtils;
-
 /**
  * Tests for {@link FileRotator}.
  */
@@ -67,7 +64,7 @@ public class FileRotatorTest extends AndroidTestCase {
         super.setUp();
 
         mBasePath = getContext().getFilesDir();
-        IoUtils.deleteContents(mBasePath);
+        FsUtil.deleteContents(mBasePath);
     }
 
     public void testEmpty() throws Exception {

services/tests/servicestests/src/com/android/server/net/NetworkPolicyManagerServiceTest.java

@@ -162,13 +162,13 @@ import androidx.test.runner.AndroidJUnit4;
 
 import com.android.internal.util.test.BroadcastInterceptingContext;
 import com.android.internal.util.test.BroadcastInterceptingContext.FutureIntent;
+import com.android.internal.util.test.FsUtil;
 import com.android.server.DeviceIdleInternal;
 import com.android.server.LocalServices;
 import com.android.server.usage.AppStandbyInternal;
 
 import com.google.common.util.concurrent.AbstractFuture;
 
-import libcore.io.IoUtils;
 import libcore.io.Streams;
 
 import org.junit.After;
@@ -2385,7 +2385,7 @@ public class NetworkPolicyManagerServiceTest {
     private void setNetpolicyXml(Context context) throws Exception {
         mPolicyDir = context.getFilesDir();
         if (mPolicyDir.exists()) {
-            IoUtils.deleteContents(mPolicyDir);
+            FsUtil.deleteContents(mPolicyDir);
         }
         if (!TextUtils.isEmpty(mNetpolicyXml)) {
             final String assetPath = NETPOLICY_DIR + "/" + mNetpolicyXml;

tests/utils/testutils/java/com/android/internal/util/test/FsUtil.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2021 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.internal.util.test;
+
+import java.io.File;
+
+public class FsUtil {
+
+    /**
+     * Deletes all files under a given directory. Deliberately ignores errors, on the assumption
+     * that test cleanup is only supposed to be best-effort.
+     *
+     * @param dir directory to clear its contents
+     */
+    public static void deleteContents(File dir) {
+        File[] files = dir.listFiles();
+        if (files != null) {
+            for (File file : files) {
+                if (file.isDirectory()) {
+                    deleteContents(file);
+                }
+                file.delete();
+            }
+        }
+    }
+}