adding existing API check before publishing

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/util/DeviceManagerUtil.java

@@ -172,6 +172,7 @@ public final class DeviceManagerUtil {
         APIIdentifier id = new APIIdentifier(config.getOwner(), config.getName(), config.getVersion());
         API api = new API(id);
         try {
+	        if(!provider.isAPIAvailable(id)) {
 		        api.setContext(config.getContext());
 		        api.setUrl(config.getEndpoint());
 		        api.setUriTemplates(getURITemplates(config.getEndpoint(),
@@ -183,6 +184,7 @@ public final class DeviceManagerUtil {
 		        api.setTransports(config.getTransports());
 
 		        provider.addAPI(api);
+	        }
         } catch (APIManagementException e) {
             throw new DeviceManagementException("Error occurred while registering the API", e);
         }

features/device-mgt/org.wso2.carbon.device.mgt.server.feature/src/main/resources/conf/user-api-publisher-config.xml

@@ -21,7 +21,7 @@
             <API>
                <Name>appmanager</Name>
                <Owner>admin</Owner>
-               <Context>devices</Context>
+               <Context>/devices</Context>
                <Version>1.0.0</Version>
                <Endpoint>http://localhost:9763/</Endpoint>
                <Transports>http,https</Transports>