From b8f085da20cdf13e61e2aeae5b767ddcd18a5cd8 Mon Sep 17 00:00:00 2001
From: Harshan Liyanage <harshan@wso2.com>
Date: Mon, 19 Jun 2017 16:58:42 +0530
Subject: [PATCH] Added null checks for device cache in-case cache is disabled.

---
 .../cache/impl/DeviceCacheManagerImpl.java    | 41 ++++++++++++-------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/cache/impl/DeviceCacheManagerImpl.java b/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/cache/impl/DeviceCacheManagerImpl.java
index 6759ef7e5bd..2bcd5e2797e 100644
--- a/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/cache/impl/DeviceCacheManagerImpl.java
+++ b/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/cache/impl/DeviceCacheManagerImpl.java
@@ -55,29 +55,35 @@ public class DeviceCacheManagerImpl implements DeviceCacheManager {
     @Override
     public void addDeviceToCache(DeviceIdentifier deviceIdentifier, Device device, int tenantId) {
         Cache<DeviceCacheKey, Device> lCache = DeviceManagerUtil.getDeviceCache();
-        DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
-        if (lCache.containsKey(cacheKey)) {
-            this.updateDeviceInCache(deviceIdentifier, device, tenantId);
-        } else {
-            lCache.put(cacheKey, device);
+        if (lCache != null) {
+            DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
+            if (lCache.containsKey(cacheKey)) {
+                this.updateDeviceInCache(deviceIdentifier, device, tenantId);
+            } else {
+                lCache.put(cacheKey, device);
+            }
         }
     }
 
     @Override
     public void removeDeviceFromCache(DeviceIdentifier deviceIdentifier, int tenantId) {
         Cache<DeviceCacheKey, Device> lCache = DeviceManagerUtil.getDeviceCache();
-        DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
-        if (lCache.containsKey(cacheKey)) {
-            lCache.remove(cacheKey);
+        if (lCache != null) {
+            DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
+            if (lCache.containsKey(cacheKey)) {
+                lCache.remove(cacheKey);
+            }
         }
     }
 
     @Override
     public void removeDevicesFromCache(List<DeviceCacheKey> deviceList) {
         Cache<DeviceCacheKey, Device> lCache = DeviceManagerUtil.getDeviceCache();
-        for (DeviceCacheKey cacheKey : deviceList) {
-            if (lCache.containsKey(cacheKey)) {
-                lCache.remove(cacheKey);
+        if (lCache != null) {
+            for (DeviceCacheKey cacheKey : deviceList) {
+                if (lCache.containsKey(cacheKey)) {
+                    lCache.remove(cacheKey);
+                }
             }
         }
     }
@@ -85,16 +91,21 @@ public class DeviceCacheManagerImpl implements DeviceCacheManager {
     @Override
     public void updateDeviceInCache(DeviceIdentifier deviceIdentifier, Device device, int tenantId) {
         Cache<DeviceCacheKey, Device> lCache = DeviceManagerUtil.getDeviceCache();
-        DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
-        if (lCache.containsKey(cacheKey)) {
-            lCache.replace(cacheKey, device);
+        if (lCache != null) {
+            DeviceCacheKey cacheKey = getCacheKey(deviceIdentifier, tenantId);
+            if (lCache.containsKey(cacheKey)) {
+                lCache.replace(cacheKey, device);
+            }
         }
     }
 
     @Override
     public Device getDeviceFromCache(DeviceIdentifier deviceIdentifier, int tenantId) {
         Cache<DeviceCacheKey, Device> lCache = DeviceManagerUtil.getDeviceCache();
-        return lCache.get(getCacheKey(deviceIdentifier, tenantId));
+        if (lCache != null) {
+            return lCache.get(getCacheKey(deviceIdentifier, tenantId));
+        }
+        return null;
     }