fix(mobile-client): initialize key value store inside mobile client constructor to prevent NPE (#2383)

Author: raphkim

aws-android-sdk-mobile-client/src/main/java/com/amazonaws/mobile/client/AWSMobileClient.java

@@ -126,9 +126,7 @@
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import static com.amazonaws.mobile.client.results.SignInState.CUSTOM_CHALLENGE;
 
@@ -261,7 +259,7 @@ public final class AWSMobileClient implements AWSCredentialsProvider {
     private volatile CountDownLatch showSignInWaitLatch;
     private Object federateWithCognitoIdentityLockObject;
     private Object initLockObject;
-    AWSMobileClientStore mStore;
+    KeyValueStore mStore;
     AWSMobileClientCognitoIdentityProvider provider;
     DeviceOperations mDeviceOperations;
     AmazonCognitoIdentityProvider userpoolLL;
@@ -327,6 +325,7 @@ private AWSMobileClient() {
         federateWithCognitoIdentityLockObject = new Object();
         showSignInWaitLatch = new CountDownLatch(1);
         initLockObject = new Object();
+        mStore = new DummyStore();
     }
 
     /**
@@ -3802,64 +3801,6 @@ public String[] getProviderPermissions() {
     }
 }
 
-class AWSMobileClientStore {
-    AWSKeyValueStore mAWSKeyValueStore;
-
-    private ReadWriteLock mReadWriteLock = new ReentrantReadWriteLock();
-
-    AWSMobileClientStore(AWSMobileClient client) {
-        mAWSKeyValueStore = new AWSKeyValueStore(client.mContext,
-                AWSMobileClient.SHARED_PREFERENCES_KEY,
-                client.mIsPersistenceEnabled);
-    }
-
-    Map<String, String> get(final String... keys) {
-        try {
-            mReadWriteLock.readLock().lock();
-            HashMap<String, String> attributes = new HashMap<String, String>();
-            for (String key : keys) {
-                attributes.put(key, mAWSKeyValueStore.get(key));
-            }
-            return attributes;
-        } finally {
-            mReadWriteLock.readLock().unlock();
-        }
-    }
-
-    String get(final String key) {
-        try {
-            mReadWriteLock.readLock().lock();
-            return mAWSKeyValueStore.get(key);
-        } finally {
-            mReadWriteLock.readLock().unlock();
-        }
-    }
-
-    void set(final Map<String, String> attributes) {
-        try {
-            mReadWriteLock.writeLock().lock();
-            for (String key : attributes.keySet()) {
-                mAWSKeyValueStore.put(key, attributes.get(key));
-            }
-        } finally {
-            mReadWriteLock.writeLock().unlock();
-        }
-    }
-
-    void set(final String key, final String value) {
-        try {
-            mReadWriteLock.writeLock().lock();
-            mAWSKeyValueStore.put(key, value);
-        } finally {
-            mReadWriteLock.writeLock().unlock();
-        }
-    }
-
-    void clear() {
-        mAWSKeyValueStore.clear();
-    }
-}
-
 /**
  * A duplicate class of AWSEnhancedCognitoIdentityProvider that provides the ability to
  * branch into developer authenticated identities.

aws-android-sdk-mobile-client/src/main/java/com/amazonaws/mobile/client/AWSMobileClientStore.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2017-2021 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * 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.amazonaws.mobile.client;
+
+import com.amazonaws.internal.keyvaluestore.AWSKeyValueStore;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * Uses {@link AWSKeyValueStore} to persistently store values for mobile client.
+ */
+final class AWSMobileClientStore implements KeyValueStore {
+    private final AWSKeyValueStore mAWSKeyValueStore;
+    private final ReadWriteLock mReadWriteLock;
+
+    AWSMobileClientStore(AWSMobileClient client) {
+        mAWSKeyValueStore = new AWSKeyValueStore(client.mContext,
+                AWSMobileClient.SHARED_PREFERENCES_KEY,
+                client.mIsPersistenceEnabled);
+        mReadWriteLock = new ReentrantReadWriteLock();
+    }
+
+    @Override
+    public Map<String, String> get(final String... keys) {
+        try {
+            mReadWriteLock.readLock().lock();
+            HashMap<String, String> attributes = new HashMap<String, String>();
+            for (String key : keys) {
+                attributes.put(key, mAWSKeyValueStore.get(key));
+            }
+            return attributes;
+        } finally {
+            mReadWriteLock.readLock().unlock();
+        }
+    }
+
+    @Override
+    public String get(final String key) {
+        try {
+            mReadWriteLock.readLock().lock();
+            return mAWSKeyValueStore.get(key);
+        } finally {
+            mReadWriteLock.readLock().unlock();
+        }
+    }
+
+    @Override
+    public void set(final Map<String, String> attributes) {
+        try {
+            mReadWriteLock.writeLock().lock();
+            for (String key : attributes.keySet()) {
+                mAWSKeyValueStore.put(key, attributes.get(key));
+            }
+        } finally {
+            mReadWriteLock.writeLock().unlock();
+        }
+    }
+
+    @Override
+    public void set(final String key, final String value) {
+        try {
+            mReadWriteLock.writeLock().lock();
+            mAWSKeyValueStore.put(key, value);
+        } finally {
+            mReadWriteLock.writeLock().unlock();
+        }
+    }
+
+    @Override
+    public void clear() {
+        mAWSKeyValueStore.clear();
+    }
+}

aws-android-sdk-mobile-client/src/main/java/com/amazonaws/mobile/client/DummyStore.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2017-2021 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * 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.amazonaws.mobile.client;
+
+import java.util.Map;
+
+/**
+ * Default key value store to be replaced during mobile client initialization.
+ */
+final class DummyStore implements KeyValueStore {
+    @Override
+    public Map<String, String> get(String... keys) {
+        throwNotInitializedException();
+        return null;
+    }
+
+    @Override
+    public String get(String key) {
+        throwNotInitializedException();
+        return null;
+    }
+
+    @Override
+    public void set(Map<String, String> attributes) {
+        throwNotInitializedException();
+    }
+
+    @Override
+    public void set(String key, String value) {
+        throwNotInitializedException();
+
+    }
+
+    @Override
+    public void clear() {
+        throwNotInitializedException();
+    }
+
+    private void throwNotInitializedException() {
+        throw new IllegalStateException("AWSMobileClient has not been initialized yet.");
+    }
+}

aws-android-sdk-mobile-client/src/main/java/com/amazonaws/mobile/client/KeyValueStore.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017-2021 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * 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.amazonaws.mobile.client;
+
+import java.util.Map;
+
+/**
+ * Allows key-value pairs to be stored and retrieved.
+ */
+interface KeyValueStore {
+    Map<String, String> get(final String... keys);
+    String get(final String key);
+    void set(final Map<String, String> attributes);
+    void set(final String key, final String value);
+    void clear();
+}