Connect MS OLAP with Java - java

I have a data source which has a provider MSOLAP I want to connect to this source via java based application. I used the following:
public static void main(String[] args) throws Exception {
// Load the driver
Class.forName("org.olap4j.driver.xmla.XmlaOlap4jDriver");
// Connect
final Connection connection =
DriverManager.getConnection(
// This is the SQL Server service end point.
"jdbc:xmla:Server=http://localhost:81/mondrian/xmla"
// Tells the XMLA driver to use a SOAP request cache layer.
// We will use an in-memory static cache.
+ ";Cache=org.olap4j.driver.xmla.cache.XmlaOlap4jNamedMemoryCache"
// Sets the cache name to use. This allows cross-connection
// cache sharing. Don't give the driver a cache name and it
// disables sharing.
+ ";Cache.Name=MyNiftyConnection"
// Some cache performance tweaks.
// Look at the javadoc for details.
+ ";Cache.Mode=LFU;Cache.Timeout=600;Cache.Size=100",
// XMLA is over HTTP, so BASIC authentication is used.
null,
null);
// We are dealing with an olap connection. we must unwrap it.
final OlapConnection olapConnection = connection.unwrap(OlapConnection.class);
// Check if it's all groovy
ResultSet databases = olapConnection.getMetaData().getDatabases();
databases.first();
System.out.println(
olapConnection.getMetaData().getDriverName()
+ " -> "
+ databases.getString(1));
// Done
connection.close();
}
I get the class OlapConnection is not compiled. I have two questions: 1- I am using maven to build this test and it is not showing errors why would this class not be found?
2- is there any other way to connect to MSOLAP without using olap4j?

This isn't how you connect remotely to an XMLA service. Start by reading this code, and then you'll need to edit the connection string.
In SSAS, the connection string should look something like this:
jdbc:xmla:Server=http://localhost/olap/msmdpump.dll;Catalog=myCatalog

Related

How to convert Azure DB URL to localhost DB URL?

I've got an Azure SQL Server database that I'm connecting to via JDBC, but want to connect instead to my SQL Server "localhost". In SSMS, I connect to localhost without needing a password. So, do I still need to enter a password in Java?
I have a code like this :
String connectionUrl =
"jdbc:sqlserver://etcetc.database.windows.net:1433;"
+ "database=med;"
+ "user=windersan#salemimed;"
+ "password=********;"
+ "encrypt=true;"
+ "trustServerCertificate=false;"
// + "hostNameInCertificate=*.database.windows.net;"
+ "loginTimeout=30;";
How do I change this to connect instead to localhost?
Just replace the etcetc.database.windows.net by localhost and replace the port number 1433 by the number that you are using.
I have used SQLServerDataSource class to make the work easier. You can also create a string URL and set it in the DriverManger.getConnection().
Try with this code :
SQLServerDataSource dataSource = new SQLServerDataSource();
dataSource.setUser("windersan#salemimed");
dataSource.setPassword("********");
dataSource.setServerName("localhost");
// set the port number of your system below.
dataSource.setPortNumber(1433);
dataSource.setDatabaseName("med");
dataSource.setEncrypt(true);
dataSource.setHostNameInCertificate("*.database.windows.net");
dataSource.setTrustServerCertificate(false);
Connection connection = dataSource.getConnection();
Please refer to this links down below for more info.
Microsoft Docs - ISQLServerDataSource Interface - This contains the list of methods that you can use to set the various properties in the datasource.
Microsoft Docs - How to work with the connection - This contains examples of the possible ways to connect to a SQL Server database.
the first line of your concatenated string contains the url etcetc.database.windows.net:1433 this is the location of the database server, and the bit you should change.
Also, it might be worth doing a google search on connecting to SqlServer with JDBC to see if there are any examples out there.

Hive JDBC connection problems

I am trying to connect to Hive2 server via JDBC with kerberos authentication. After numerous attempts to make it work, I can't get it to work with the Cloudera driver.
If someone can help me to solve the problem, I can greatly appreciate it.
I have this method:
private Connection establishConnection() {
final String driverPropertyClassName = "driver";
final String urlProperty = "url";
Properties hiveProperties = config.getMatchingProperties("hive.jdbc");
String driverClassName = (String) hiveProperties.remove(driverPropertyClassName);
String url = (String) hiveProperties.remove(urlProperty);
Configuration hadoopConfig = new Configuration();
hadoopConfig.set("hadoop.security.authentication", "Kerberos");
String p = config.getProperty("hadoop.core.site.path");
Path path = new Path(p);
hadoopConfig.addResource(path);
UserGroupInformation.setConfiguration(hadoopConfig);
Connection conn = null;
if (driverClassName != null) {
try {
UserGroupInformation.loginUserFromKeytab(config.getProperty("login.user"), config.getProperty("keytab.file"));
Driver driver = (Driver) Class.forName(driverClassName).newInstance();
DriverManager.registerDriver(driver);
conn = DriverManager.getConnection(url, hiveProperties);
} catch (Throwable e) {
LOG.error("Failed to establish Hive connection", e);
}
}
return conn;
}
URL for the server, that I am getting from the properties in the format described in Cloudera documentation
I am getting an exception:
2018-05-05 18:26:49 ERROR HiveReader:147 - Failed to establish Hive connection
java.sql.SQLException: [Cloudera][HiveJDBCDriver](500164) Error initialized or created transport for authentication: Peer indicated failure: Unsupported mechanism type PLAIN.
at com.cloudera.hiveserver2.hivecommon.api.HiveServer2ClientFactory.createTransport(Unknown Source)
at com.cloudera.hiveserver2.hivecommon.api.ZooKeeperEnabledExtendedHS2Factory.createClient(Unknown Source)
...
I thought, that it is missing AuthMech attribute and added AuthMech=1 to the URL. Now I am getting:
java.sql.SQLNonTransientConnectionException: [Cloudera][JDBC](10100) Connection Refused: [Cloudera][JDBC](11640) Required Connection Key(s): KrbHostFQDN, KrbServiceName; [Cloudera][JDBC](11480) Optional Connection Key(s): AsyncExecPollInterval, AutomaticColumnRename, CatalogSchemaSwitch, DecimalColumnScale, DefaultStringColumnLength, DelegationToken, DelegationUID, krbAuthType, KrbRealm, PreparedMetaLimitZero, RowsFetchedPerBlock, SocketTimeOut, ssl, StripCatalogName, transportMode, UseCustomTypeCoercionMap, UseNativeQuery, zk
at com.cloudera.hiveserver2.exceptions.ExceptionConverter.toSQLException(Unknown Source)
at com.cloudera.hiveserver2.jdbc.common.BaseConnectionFactory.checkResponseMap(Unknown Source)
...
But KrbHostFQDN is already specified in the principal property as required in the documentation.
Am I missing something or is this documentation wrong?
Below is the one of the similar kind of problem statement in Impala (just JDBC engine changes others are same) that is resolved by setting "KrbHostFQDN" related properties in JDBC connection string itself.
Try to use the URL below. Hopefully works for u.
String jdbcConnStr = "jdbc:impala://myserver.mycompany.corp:21050/default;SSL=1;AuthMech=1;KrbHostFQDN=myserver.mycompany.corp;KrbRealm=MYCOMPANY.CORP;KrbServiceName=impala"
I suppose that if you are not using SSL=1 but only Kerberos, you just drop that part from the connection string and don't worry about setting up SSL certificates in the java key store, which is yet another hassle.
However in order to get Kerberos to work properly we did the following:
Install MIT Kerberos 4.0.1, which is a kerberos ticket manager. (This is for Windows)
This ticket manager asks you for authentication every time you initiate a connection, creates a ticket and stores it in a kerberos_ticket.dat binary file, whose location can be configured somehow but I do not recall exactly how.
Finally, before launching your JAVA app you have to set an environment variable KRB5CCNAME=C:/path/to/kerberos_ticket.dat. In your java app, you can check that the variable was correctly set by doing System.out.println( "KRB5CCNAME = " + System.getenv( "KRB5CCNAME" ) ). If you are working with eclipse or other IDE you might even have to close the IDE,set up the environment variable and start the IDE again.
NOTE: this last bit is very important, I have observed that if this variable is not properly set up, the connection wont be established...
In Linux, instead MIT Kerberos 4.0.1, there is a program called kinit which does the same thing, although without a graphical interface, which is even more convenient for automation.
I wanted to put it in the comment but it was too long for the comment, therefore I am placing it here:
I tried your suggestion and got another exception:
java.sql.SQLException: [Cloudera]HiveJDBCDriver Error
creating login context using ticket cache: Unable to obtain Principal
Name for authentication .
May be my problem is, that I do not have environment variable KRB5CCNAME set.
I, honestly, never heard about it before.
What is supposed to be in that ticket file.
I do have, however, following line in my main method:
System.setProperty("java.security.krb5.conf", "path/to/krb5.conf");
Which is supposed to be used by
UserGroupInformation.loginUserFromKeytab(config.getProperty("login.user"), config.getProperty("keytab.file"));
to obtain the kerberos ticket.
To solve this issue update Java Cryptography Extension for the Java version that you use in your system.
Here's the link when you can download JCE for Java 1.7
Uncompress and overwrite those files in $JDK_HOME/jre/lib/security
Restart your computer.

How to hook up AWS RDS - Aurora with AWS Lambda Java function

I am trying to hook up AWS RDS Aurora database with AWS Lambda Java function. For this, I am yet to see any concrete examples. I have seen some examples but they are non java.
I would also like to configure a mySQL DBMS tool with Aurora which I am not able to do :( Can someone help me with that as well. I have got the connection strings from https://console.aws.amazon.com/rds/home?region=us-east-1#dbinstances.
Also, the code I am trying to connect to DB via Lambda Java is:
private Statement createConnection(Context context) {
logger = context.getLogger();
try {
String url = "jdbc:mysql://HOSTNAME:3306";
String username = "USERNAME";
String password = "PASSWORD";
Connection conn = DriverManager.getConnection(url, username, password);
return conn.createStatement();
} catch (Exception e) {
e.printStackTrace();
logger.log("Caught exception: " + e.getMessage());
}
return null;
}
And yes, this doesn't help as I always get null using the db instance config.
RDS needs be in a security group that opens the DB port to the Security Group attached to the ENI of the lambda.
To enable your Lambda function to access resources inside your private VPC, you must provide additional VPC-specific configuration
information that includes VPC subnet IDs and security group IDs. AWS
Lambda uses this information to set up elastic network interfaces
(ENIs) that enable your function to connect securely to other
resources within your private VPC.
http://docs.aws.amazon.com/lambda/latest/dg/vpc.html
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html

Cant connect to mariadb from java - only with mysqldeveloper [duplicate]

I am trying to connect to a database in Mariadb through a simple java application but the connection is told to be unsuccessful and an Exception is thrown. I have done the similar connection using mysql and it was working correctly. The problem is maybe with the driver here.
try{
Class.forName("org.mariadb.jdbc.Driver");
Connection connection = DriverManager.getConnection(
"jdbc:mariadb://localhost:3306/project", "root", "");
Statement statement = connection.createStatement();
String uname="xyz",pass="abc";
statement.executeUpdate("insert into user values('"+uname+"','"+pass+"')");}//end of try block
I looked up the internet for the help and came by that driver class provided by the MariaDB Client Library for Java Applications is not com.mysql.jdbc.Driver but org.mariadb.jdbc.Driver! I changed it accordingly but it seems the problem is with the very first line inside the try block. The driver is not loading at all.
Also, I have added the mysql jar file to the libraries of my java application as in the screen-shot below. Please help me through this.
It appears that you are trying to use jdbc:mariadb://... to establish a connection to a MariaDB server instance using the MySQL JDBC Driver. That probably won't work because the MySQL JDBC Driver would use jdbc:mysql://..., regardless of whether it is connecting to a MySQL server or a MariaDB server. That is, the connection string must match the driver that is being used (rather than the database server being accessed).
The MySQL and MariaDB drivers are supposed to be somewhat interchangeable, but it only seems prudent to use the MariaDB connector when accessing a MariaDB server. For what it's worth, the combination of mariadb-java-client-1.1.7.jar
and
Connection con = DriverManager.getConnection(
"jdbc:mariadb://localhost/project",
"root",
"whatever");
worked for me. I downloaded the MariaDB Client Library for Java from here:
https://downloads.mariadb.org/client-java/1.1.7/
which I arrived at via
https://downloads.mariadb.org/
Additional notes:
There is no need for a Class.forName() statement in your Java code.
The default configuration for MariaDB under Mageia may include the skip-networking directive in /etc/my.cnf. You will need to remove (or comment out) that directive if you want to connect to the database via JDBC because JDBC connections always look like "network" connections to MySQL/MariaDB, even if they are connections from localhost. (You may need to tweak the bind-address value to something like 0.0.0.0 as well.)
An additional note:
Exploring the MariaDB JDBC driver, I found this inside the url parsing file:
Project: https://github.com/MariaDB/mariadb-connector-j.git
File: src/main/java/org/mariadb/jdbc/UrlParser.java
public static UrlParser parse(final String url, Properties prop) throws SQLException {
....
if (url.startsWith("jdbc:mysql:")) {
UrlParser urlParser = new UrlParser();
parseInternal(urlParser, url, prop);
return urlParser;
} else {
if (url.startsWith("jdbc:mariadb:")) {
UrlParser urlParser = new UrlParser();
parseInternal(urlParser, "jdbc:mysql:" + url.substring(13), prop);
return urlParser;
}
}
As you can see, the string "jdbc:mariadb:" is always replaced with "jdbc:mysql:" internally. So when it comes to the MariaDB driver, whether it is :mariadb: or :mysql: it always gets parsed as "jdbc:mysql:".
No difference.
if (url.startsWith("jdbc:mariadb:")) {
....
parseInternal(urlParser, "jdbc:mysql:" + url.substring(13), prop);
....

Access (.mdb) Database manipulation with jdbc

Background: Working on an application to be run on an Apache server hosted by Network Solutions. Friend/Customer insisted on using an Access Database instead of SQL database.
Current Problem: Wrote a Java test program to make sure I can connect to the database before I dive head first into writing the whole backend. When I run this code on the JVM of the apache server the final product will be hosted:
import java.sql.*;
import java.io.*;
public class test {
public static void main(String[] args) {
try {
Class driverClass = Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
DriverManager.registerDriver((Driver) driverClass.newInstance());
// set this to a MS Access DB you have on your machine
String filename = new File(".").getCanonicalPath() + "/ITEMS.mdb";
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=";
database+= filename.trim(); // add on to the end
// now we can get the connection from the DriverManager
System.out.println(database);
Connection conn = DriverManager.getConnection( database );
} catch (Exception e) {
System.out.println("Error: " + e.getMessage() + " " + e.getLocalizedMessage());
e.printStackTrace();
}
}
}
I get a null pointer exception on the line Connection conn= DriverManager.getConnection( database)
Here is the stacktrace:
java.lang.NullPointerException
at sun.jdbc.odbc.JdbcOdbcDriver.initialize(JdbcOdbcDriver.java:436)
at sun.jdbc.odbc.JdbcOdbcDriver.connect(JdbcOdbcDriver.java:153)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at test.main(test.java:20)
To write this test I used this as my primary source: http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=2691&lngWId=2
String strconnect="jdbc:odbc:DRIVER=Microsoft Access Driver (*.mdb, *.accdb);DBQ="
Sring filename="some path";
StringBuilder a =new StringBuilder();
a.append(strconnect);
a.append(filename);
String db = a.toString();
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection c= DriverManager.getrConnection(db,"","")
Statement stmt = c.createStament();
String query = "some query";
stmt.executeQuery(query);
c.close();
Never get canonical Path, Either Specify the path of the access file or use JFile Explore and get path
also don't forget to close connection
Since you mention apache, I will presume that the server is running Linux or BSD.
In that case, please have a look at the following:
Connecting to access database from linux
Good Linux ODBC drivers for Access are expensive! (US$850 for a single machine!)
There is no default drivers for Access provided on linux, and the JDBC ODBC won't work unless you install one.
Unless there is a very special and overwhelming good reason for using an Access database as the backend to a website on a linux server, tell your friend that this is not technically or even economically coherent.
If you need a lightweight database on the server, use SQLite: it's free, there is good support for connecting to it from Java in linux, there is good tooling (even browser plugins), and you can always convert that database to Access if your friend want to get an Access backup once in a while.
Otherwise, go for PostgreSQL or MySQL like everyone does (generally for a good reason).

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