[GORA-428] Null pointer exception caused by incorrect handling of gora.mongodb.login values that don't validate

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.5
• Fix Version/s: 0.6.1
• Component/s: gora-mongodb
• Environment: Ubuntu, Nutch2
• Assignee: Unassigned
• Reporter: Kevin Findlay
• Created: 21/Aug/15 08:44
• Updated: 29/Aug/15 22:47
• Resolved: 29/Aug/15 20:12

Description

A null pointer exception occurs when the gora.mongodb.login=nutch does not validate.

Line 250 of the MongoStore class in method "private DB getDB(final String servers, final String dbname, final String login, final String secret) throws UnknownHostException" returns a null when the user is not validated.

if (login != null && secret != null)

{ ****PROBLEM**** auth = db.authenticate(login, secret.toCharArray()); }

This causes the method to return a null to :
mongoClientDB = getDB(vPropMongoServers, vPropMongoDb, vPropMongoLogin, vPropMongoSecret);

In line 173 of MongoStore "public void initialize(final Class<K> keyClass,
final Class<T> pPersistentClass, final Properties properties)"

The code attempts to use this null value
****PROBLEM***
as mongoClientColl = mongoClientDB
.getCollection(mapping.getCollectionName());

The solution is to check for a null point for mongoClientDB prior to use or, better, write specific code to report when a login to MongoDB fails due to authentication.

ERROR MESSAGE

InjectorJob: org.apache.gora.util.GoraException: java.lang.NullPointerException
at org.apache.gora.store.DataStoreFactory.createDataStore(DataStoreFactory.java:169)
at org.apache.gora.store.DataStoreFactory.createDataStore(DataStoreFactory.java:137)
at org.apache.nutch.storage.StorageUtils.createWebStore(StorageUtils.java:78)
at org.apache.nutch.crawl.InjectorJob.run(InjectorJob.java:218)
at org.apache.nutch.crawl.InjectorJob.inject(InjectorJob.java:252)
at org.apache.nutch.crawl.InjectorJob.run(InjectorJob.java:275)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.nutch.crawl.InjectorJob.main(InjectorJob.java:284)
Caused by: java.lang.NullPointerException
at org.apache.gora.mongodb.store.MongoStore.initialize(MongoStore.java:173)
at org.apache.gora.store.DataStoreFactory.initializeDataStore(DataStoreFactory.java:104)
at org.apache.gora.store.DataStoreFactory.createDataStore(DataStoreFactory.java:163)
... 7 more