Develop Reference

Code in Persistent EHcache docs not working java

I want to use EHcache in my java project. They have persistent storage support. I have read the docs
https://www.ehcache.org/documentation/2.7/configuration/fast-restart.html and found this code
Configuration cacheManagerConfig = new Configuration()
.diskStore(new DiskStoreConfiguration()
.path("/tmp/file.txt"));
CacheConfiguration cacheConfig = new CacheConfiguration()
.name("my-cache")
.maxBytesLocalHeap(16, MemoryUnit.MEGABYTES)
.maxBytesLocalOffHeap(256, MemoryUnit.MEGABYTES)
.persistence(new PersistenceConfiguration().strategy(Strategy.LOCALTEMPSWAP));
cacheManagerConfig.addCache(cacheConfig);
CacheManager cacheManager = new CacheManager(cacheManagerConfig);
Ehcache myCache = cacheManager.getEhcache("my-cache");
I have imported the dependency but it shows lots of error.
Error I got
'Configuration' is abstract; cannot be instantiated
Please provide some simple steps to make use of this library. I read the docs but the code doesn't get worked. Help me with some solutions.

Found the Answer.
try(PersistentCacheManager persistentCacheManager =
newCacheManagerBuilder()
.with(persistence("/tmp/myProjectCache"))
.withCache("test-cache",
newCacheConfigurationBuilder(
String.class, String.class,
newResourcePoolsBuilder()
.heap(1, EntryUnit.ENTRIES)
.offheap(1, MemoryUnit.MB)
.disk(2, MemoryUnit.MB, true)
)
).build(true)) {
org.ehcache.Cache cache = persistentCacheManager.getCache("test-cache", String.class, String.class);
cache.put("name1","steven");
cache.put("name2","prince");
System.out.println(cache.get("name1"));
System.out.println(cache.get("name2"));
}

Unable to connect and load data from Oracle, using Ignite V2.0

I am trying to configure and read data from existing Oracle tables
However, I get error message while calling cache.loadCache(); this line.
It shows error message as
Message as
session:javax.cache.integration.CacheWriterException: Failed to start store
session [tx=null]Caused by: java.sql.SQLException: No suitable driver found
for jdbc:oracle:thin:#192.168.2.218:1521:xe at
org.h2.jdbcx.JdbcDataSource.getJdbcConnection(JdbcDataSource.java:190) at
org.h2.jdbcx.JdbcDataSource.getXAConnection(JdbcDataSource.java:351) at
org.h2.jdbcx.JdbcDataSource.getPooledConnection(JdbcDataSource.java:383) at
org.h2.jdbcx.JdbcConnectionPool.getConnectionNow(JdbcConnectionPool.java:226)
at
org.h2.jdbcx.JdbcConnectionPool.getConnection(JdbcConnectionPool.java:198)
at
CacheConfiguration<String, TempClass> cacheCfg = new CacheConfiguration<String, TempClass>();
cacheCfg.setName("Test_CacheConfig");
IgniteConfiguration igniteConfig = new IgniteConfiguration();
Factory<TempClassCacheStore> factory = FactoryBuilder.factoryOf(TempClassCacheStore.class);
cacheCfg.setReadThrough(true);
cacheCfg.setWriteThrough(true);
cacheCfg.setIndexedTypes(String.class, TempClass.class);
cacheCfg.setCacheStoreFactory(factory);
cacheCfg.setCacheStoreSessionListenerFactories(new Factory<CacheStoreSessionListener>() {
#Override
public CacheStoreSessionListener create() {
CacheJdbcStoreSessionListener lsnr = new CacheJdbcStoreSessionListener();
lsnr.setDataSource(JdbcConnectionPool.create("jdbc:oracle:thin:#192.168.2.218:1521:xe", "test", "test"));
return lsnr;
}
});
Ignite ignite = Ignition.start(igniteConfig);
IgniteCache<String, TempClass> cache = ignite.getOrCreateCache(cacheCfg);
cache.loadCache(null);
SqlFieldsQuery sql = new SqlFieldsQuery("SELECT ID_, NAME_ FROM TEST_TABLE");
QueryCursor<List<?>> cursor = cache.query(sql);
I have configured CacheStore for TempClass also as shown in
https://apacheignite.readme.io/docs/persistent-store#cachestore
Any help will be highly appreciated

As you're trying to load data from oracle to Ignite, you need to have Oracle JDBC Driver in classpath. Just put the driver JAR into IGNITE_HOME/libs folder prior to starting the nodes and run loading again.

Creating mongodb database user in Java using spring data mongodb

I need to create a mongodb database user in a Spring boot application using spring data mongodb. I will be creating this user as part of application startup.
I could not find any reference for doing this using spring data mongodb.
Is that possible by using Spring data mongodb?

I had the same issue in the past and I end up by creating the user before the context load, like this:
#Configuration
#EnableAutoConfiguration
#ComponentScan
public class Application extends SpringBootServletInitializer {
#SuppressWarnings("resource")
public static void main(final String[] args) {
createMongoDbUser();
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
}
private void createMongoDbUser() {
MongoClient mongo = new MongoClient(HOST, PORT);
MongoDatabase db = mongo.getDatabase(DB);
Map<String, Object> commandArguments = new BasicDBObject();
commandArguments.put("createUser", USER_NAME);
commandArguments.put("pwd", USER_PWD);
String[] roles = { "readWrite" };
commandArguments.put("roles", roles);
BasicDBObject command = new BasicDBObject(commandArguments);
db.runCommand(command);
}
}

Spring-data-mongodb will create the db all by itself if it can't find it, when declaring your mongo-db factory.
For instance, I declare my db-factory in xml using the following:
<mongo:db-factory id="mongofactory" dbname="dbNameHere" mongo-ref="mongo" />
I did not have to create it myself, it was created by spring-data-mongodb upon firing may app the first time.

Properties file on HikariCP

I tried unsuccessfully configure hikaricp and I don't see error in the code please help.
public class DatabaseManager {
private DatabaseClient[] databaseClients;
private HikariDataSource hikariDataSource;
public DatabaseManager(String absoluteFilePath) {
final HikariConfig hikariConfig = new HikariConfig(absoluteFilePath);
this.hikariDataSource = new HikariDataSource(hikariConfig);
System.out.println(hikariConfig.getUsername()); // null u-u
}
}
Properties file:
## Database Settings
dataSourceClassName=org.mariadb.jdbc.MySQLDataSource
dataSource.user=root
dataSource.password=
dataSource.databaseName=imagine-db
dataSource.portNumber=3306
dataSource.serverName=localhost

You've set the username on the data source not on the config itself. This will still work fine but you can't access it using hikariConfig.getUsername().
Try adding this to your properties file if you really need to access the user like that, although I suspect you don't.
username=root
password=

Websphere Network deployment datasource

I have installed Websphere Network deployment server 7.0.0.0
I have configured a cluster on it.
I have configured a data source on it say ORA_DS this data source using "JAAS - J2C authentication data"
When i test the ORA_DS by clicking on "Test connection" button, the test connection is success.
The issue comes when i try to access this data source using my java code.
Here is my code to access data source and create a connection:
public class DSTester
{
/**
* Return the data source.
* #return the data source
*/
private DataSource getDataSource()
{
DataSource dataSource = null;
Hashtable<String, String> env = new Hashtable<String, String>();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.ibm.websphere.naming.WsnInitialContextFactory");
env.put(Context.PROVIDER_URL, "iiop://localhost:9811");
// Retrieve datasource name
String dataSourceName = "EPLA1";
if (dataSource == null)
{
try
{
Context initialContext = new InitialContext(env);
dataSource = (DataSource) initialContext.lookup(dataSourceName);
}
catch (NamingException e1)
{
e1.printStackTrace();
return null;
}
}
return dataSource;
}
public static void main(String[] args)
throws Exception
{
DSTester dsTester = new DSTester();
DataSource ds = dsTester.getDataSource();
System.out.println(ds);
System.out.println(ds.getConnection());
}
}
Here is the output:
com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource#17e40be6
Exception in thread "P=792041:O=0:CT" java.sql.SQLException: ORA-01017: invalid username/password; logon denied
DSRA0010E: SQL State = 72000, Error Code = 1,017
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:133)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:206)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:455)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:406)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:399)
at oracle.jdbc.driver.T4CTTIoauthenticate.receiveOauth(T4CTTIoauthenticate.java:799)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:368)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:508)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:203)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:33)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:510)
at oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:275)
at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:206)
at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPhysicalConnection(OracleConnectionPoolDataSource.java:139)
at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:88)
at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:70)
at com.ibm.ws.rsadapter.spi.InternalGenericDataStoreHelper$1.run(InternalGenericDataStoreHelper.java:1175)
at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
at com.ibm.ws.rsadapter.spi.InternalGenericDataStoreHelper.getPooledConnection(InternalGenericDataStoreHelper.java:1212)
at com.ibm.ws.rsadapter.spi.WSRdbDataSource.getPooledConnection(WSRdbDataSource.java:2019)
at com.ibm.ws.rsadapter.spi.WSManagedConnectionFactoryImpl.createManagedConnection(WSManagedConnectionFactoryImpl.java:1422)
at com.ibm.ws.rsadapter.spi.WSDefaultConnectionManagerImpl.allocateConnection(WSDefaultConnectionManagerImpl.java:81)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:646)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:613)
at com.test.DSTester.main(DSTester.java:70)
The code works fine if i replace
ds.getConnection()
with
ds.getConnection("ora_user", "ora_password")
My issue is i need to get the connection without specifying login details for Oracle.
Please help me on this issue.
Any clue will be appreciated.
Thanks

I'd guess it would work if you retrieved the datasource from an application running on the WAS.
Try creating a servlet.
Context initialContext = new InitialContext();
DataSource dataSource = (DataSource) initialContext.lookup("EPLA1");
Connection con = dataSource.getConnection();
As within a servlet it is running within WAS it should be fine, if the "Test Connection" works. Running it outside is probably a different context.

I think you need to check all your configuration:
1) Is it application deplyed on cluster or into only one of cluster member?
2) JAAS - J2C authentication data - what is the scope?
Sometimes you need restar all your WAS environment. It depends on resource configuration scope
I'd recomend to you add resource refences for better configuration options.
SeeIBM Tech note