tests/src/com/android/server/telecom/tests/MockitoHelper.java

/*
 * Copyright (C) 2015 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.server.telecom.tests;

import com.android.server.telecom.Log;

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Looper;

/**
 * Helper for Mockito-based test cases.
 */
public final class MockitoHelper {
    private static final String DEXCACHE = "dexmaker.dexcache";

    private Thread mRequestThread;
    private ClassLoader mRequestThreadOriginalClassLoader;
    private ClassLoader mMainThreadOriginalClassLoader;

    /**
     * Creates a new helper, which in turn will set the context classloader so
     * it can load Mockito resources.
     *
     * @param packageClass test case class
     */
    public void setUp(Context context, Class<?> packageClass) throws Exception {
        // makes a copy of the context classloader
        mRequestThread = Thread.currentThread();
        mRequestThreadOriginalClassLoader = mRequestThread.getContextClassLoader();
        mMainThreadOriginalClassLoader = Looper.getMainLooper().getThread().getContextClassLoader();

        ClassLoader newClassLoader = packageClass.getClassLoader();

        Log.v(this, "Changing context classloader for thread %s from %s to %s",
                mRequestThread.getName(),
                mRequestThreadOriginalClassLoader,
                newClassLoader);
        mRequestThread.setContextClassLoader(newClassLoader);

        Log.v(this, "Changing context classloader for MAIN thread from %s to %s",
                mMainThreadOriginalClassLoader,
                newClassLoader);
        Looper.getMainLooper().getThread().setContextClassLoader(newClassLoader);

        String dexCache = context.getCacheDir().toString();
        Log.v(this, "Setting property %s to %s", DEXCACHE, dexCache);
        System.setProperty(DEXCACHE, dexCache);
    }

    /**
     * Restores the context classloader to the previous value.
     */
    public void tearDown() throws Exception {
        Log.v(this, "Restoring context classloaders");
        mRequestThread.setContextClassLoader(mRequestThreadOriginalClassLoader);
        Log.v(this, "Clearing property %s", DEXCACHE);
        System.clearProperty(DEXCACHE);
    }
}