Add a configuration retrieval manager.
The CarConfigurationManager is currently only returning the
configuration for speed bump, which is hard-coded.
Change-Id: I1862340ff40f8c61ec64c5eff8a0899f7f672391
Fixes: 71817274
Fixes: 70338684
Fixes: 71817172
Test: Write unit test and run the test
diff --git a/service/src/com/android/car/JsonReaderImpl.java b/service/src/com/android/car/JsonReaderImpl.java
new file mode 100644
index 0000000..2ab7c32
--- /dev/null
+++ b/service/src/com/android/car/JsonReaderImpl.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2018 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.car;
+
+import android.annotation.Nullable;
+import android.annotation.RawRes;
+import android.content.Context;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+/**
+ * An implementation of {@link com.android.car.CarConfigurationService.JsonReader} that will
+ * parse a JSON file on the system that is mapped to {@code R.raw.car_config}.
+ */
+public class JsonReaderImpl implements CarConfigurationService.JsonReader {
+ private static final int BUF_SIZE = 0x1000; // 2K chars (4K bytes)
+ private static final String JSON_FILE_ENCODING = "UTF-8";
+
+ /**
+ * Takes a resource file that is considered to be a JSON file and parses it into a String that
+ * is returned.
+ *
+ * @param resId The resource id pointing to the json file.
+ * @return A {@code String} representing the file contents, or {@code null} if
+ */
+ @Override
+ @Nullable
+ public String jsonFileToString(Context context, @RawRes int resId) {
+ InputStream is = context.getResources().openRawResource(resId);
+
+ // Note: this "try" will close the Reader, thus closing the associated InputStreamReader
+ // and InputStream.
+ try (Reader reader = new BufferedReader(new InputStreamReader(is, JSON_FILE_ENCODING))) {
+ char[] buffer = new char[BUF_SIZE];
+ StringBuilder stringBuilder = new StringBuilder();
+
+ int bufferedContent;
+ while ((bufferedContent = reader.read(buffer)) != -1) {
+ stringBuilder.append(buffer, /* offset= */ 0, bufferedContent);
+ }
+
+ return stringBuilder.toString();
+ } catch (IOException e) {
+ return null;
+ }
+ }
+}