MariaDB_About the MariaDB Java Client

via: https://mariadb.com/kb/en/about-the-mariadb-java-client/

 

Introduction

The MariaDB Client Library for Java Applications is a Type 4 JDBC driver. It was developed specifically as a lightweight JDBC connector for use with MySQL and MariaDB database servers. It's originally based on the Drizzle JDBC code, and with a lot of additions and bug fixes.

Obtaining the driver

The driver (jar and source code) can be downloaded from https://downloads.mariadb.org/client-java/

Installing the driver

Installation is as simple as placing the .jar file in your classpath.

Requirements

• Java 6
• A MariaDB or MySQL Server
• maven (only if you want build from source)

Source code

The source code is available on Launchpad: https://launchpad.net/mariadb-java-client. Development version can be obtained using

bzr branch lp:mariadb-java-client

License

GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

Building and testing the driver

The section deals with building the connector from source and testing it. If you have downloaded a ready built connector, in a jar file, then this section may be skipped.

MariaDB Client Library for Java Applications uses maven for build. You first need to ensure you have both java and maven installed on your server before you can build the driver.

To run the unit test, you'll need a MariaDB or MySQL server running on localhost (on default TCP port 3306) and a database called 'test', and user 'root' with empty password

$ bzr branch lp:mariadb-java-client #  Or, unpack the source distribution tarball
$ cd mariadb-java-client
# For the unit test run, start local mysqld mysqld, 
# ensure that user root with empty password can login
$ mvn package
# If you want to build without running unit  tests, use
# mvn -Dmaven.test.skip=true package

After that , you should have JDBC jar mariadb-java-client-x.y.z.jar in the 'target' subdirectory

Installing the driver

Installation of the client library is very simple, the jar file should be saved in an appropriate place for your application and the classpath of your application altered to include the MariaDB Client Library for Java Applications rather than your current connector.

Using the driver

The following subsections show the formatting of JDBC connection strings for MariaDB, MySQL database servers. Additionally, sample code is provided that demonstrates how to connect to one of these servers and create a table.

Driver Manager

Applications designed to use the driver manager to locate the entry point need no further configuration, the MariaDB Client Library for Java Applications will automatically be loaded and used in the way any previous MySQL driver would have been.

Driver Class

Please note that the driver class provided by the MariaDB Client Library for Java Applications is notcom.mysql.jdbc.Driver but org.mariadb.jdbc.Driver!

Connection strings

Format of the JDBC connection string is

jdbc:mysql://<host>:<port>/<database>?<key1>=<value1>&<key2>=<value2>...

Altenatively

jdbc:mariadb://<host>:<port>/<database>?<key1>=<value1>&<key2>=<value2>...

can also be used.

what't more,for cluster,it should be like this, jdbc:mariadb://<host1>:<port1>,<host2>:<port2>/<database>?<key1>=<value1>&<key2>=<value2>...

Optional URL parameters

General remark: Unknown options accepted and are silently ignored.

Following options are currently supported.

key	description	supported since version
user	Database user name	1.0.0
password	Password of database user	1.0.0
fastConnect	If set, skips check for sql_mode, assumes NO_BACKSLASH_ESCAPES is *not* set	1.0.0
useFractionalSeconds	Correctly handle subsecond precision in timestamps (feature available with MariaDB 5.3 and later).May confuse 3rd party components (Hibernated)	1.0.0
allowMultiQueries	Allows multiple statements in single executeQuery	1.0.0
dumpQueriesOnException	If set to 'true', exception thrown during query execution contain query string	1.1.0
useCompression	allow compression in MySQL Protocol	1.0.0
useSSL	Force SSL on connection	1.1.0
trustServerCertificate	When using SSL, do not check server's certificate	1.1.1
serverSslCert	Server's certificatem in DER form, or server's CA certificate. Can be used in one of 3 forms, sslServerCert=/path/to/cert.pem (full path to certificate), sslServerCert=classpath:relative/cert.pem (relative to current classpath), or as verbatim DER-encoded certificate string "------BEGING CERTIFICATE-----"	1.1.3
socketFactory	to use custom socket factory, set it to full name of the class that implements javax.net.SocketFactory	1.0.0
tcpNoDelay	Sets corresponding option on the connection socket	1.0.0
tcpKeepAlive	Sets corresponding option on the connection socket	1.0.0
tcpAbortiveClose	Sets corresponding option on the connection socket	1.1.1
tcpRcvBuf	set buffer size for TCP buffer (SO_RCVBUF)	1.0.0
tcpSndBuf	set buffer size for TCP buffer (SO_SNDBUF)	1.0.0
pipe	On Windows, specify named pipe name to connect to mysqld.exe	1.1.3
tinyInt1isBit	Datatype mapping flag, handle MySQL Tiny as BIT(boolean)	1.0.0
yearIsDateType	Year is date type, rather than numerical	1.0.0
sessionVariables	<var>=<value> pairs separated by comma, mysql session variables, set upon establishing successfull connection	1.1.0
localSocket	Allows to connect to database via Unix domain socket, if server allows it. The value is the path of Unix domain socket, i.e "socket" database parameter	1.1.4
sharedMemory	Allowed to connect database via shared memory, if server allows it. The value is base name of the shared memory	1.1.4

JDBC API Implementation Notes

Streaming result sets

By default, Statement.executeQuery() will read full result set from server before returning. With large result sets, this will require large amounts of memory. Better behavior in this case would be reading row-by-row, with ResultSet.next(), so called "streaming" feature. It is activated using Statement.setFetchSize(Integer.MIN_VALUE)

Prepared statements

The driver only uses text protocol to communicate with the database. Prepared statements (parameter substitution) is handled by the driver, on the client side.

CallableStatement

Callable statement implementation won't need to access stored procedure metadata ( mysql.proc) table, if both of following is true

• CallableStatement.getMetadata() is not used
• Parameters are accessed by index, not by name

When possible, following 2 rules above provides both better speed and eliminates concerns about SELECT privileges on mysql.proc table

Optional JDBC classes

Following optional interfaces are implemented by the org.mariadb.jdbc.MySQLDataSource class : javax.sql.DataSource, javax.sql.ConnectionPoolDataSource, javax.sql.XADataSource

Usage examples

The following code provides a basic example of how to connect to a MariaDB or MySQL server and create a table.

Creating a table on a MariaDB or MySQL Server

Connection  connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "username", "password");
Statement stmt = connection.createStatement();
stmt.executeUpdate("CREATE TABLE a (id int not null primary key, value varchar(20))");
stmt.close();
connection.close();