This document discusses using Java with MySQL. It begins with an introduction to JDBC and the Connector/J driver. It then provides examples of connecting to MySQL from Java using the JDBC URL and driver, executing queries, and using prepared statements. It demonstrates how to load configuration from properties and retrieve data from a result set. The examples show basic CRUD operations and utilizing prepared statements for security and performance.

1. David Bennett
QA Engineer
April 15th
, 2015
Using MySQL with Java
Q2 2014

2. www.percona.com2
Who are you?

Java Experts, Intermediate, Beginners

MySQL Experts, Intermediate, Beginners

Developers, DBAs, System Admins

Just interested

3. www.percona.com3
Me

QA Engineer at Percona

Designer/Developer/Consultant

20+ years in technology

15+ years working with MySQL

15+ years working with Java

Focused on web apps

Linux devotee

I love MySQL, I like Java
Dave Bennett

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Basic Topology
Java Application
(Web, Service, Desktop)
Java Runtime Engine
(JRE)
JDBC Interface
JDBC Driver (Connector/J)
MySQL

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What is JDBC?

A standardized interface between Java and SQL

JDBC is to Java what ODBC is to Windows

Virtually all Java/SQL applications use JDBC

Like ODBC, JDBC is used more and more on
Servers, Desktop use waning.

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What is Connector/J?

Most widely used JDBC Driver for MySQL today

Started life in 1998 as MM.MySQL (M. Matthews)

Acquired by MySQL AB in 2002

Owned by Oracle today, available under GPLv2

JDBC Type 4 – 100% Java – No Middleware

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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import java.sql.*;
public class MysqlVersion {
public static void main(String[] args)
throws SQLException,ClassNotFoundException {
Class.forName(
"com.mysql.jdbc.Driver"
);
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/test","user","pwd"
);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(
"SELECT concat('Hello from mysql ',version()) AS msg"
);
if (rs.next()) {
System.out.println(rs.getString("msg"));
}
rs.close(); st.close(); con.close();
}
}

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Connector/J Basic* URL
jdbc:mysql://[host][:port]/[database][?prop=val[&prop=val]]
Where: is:
host TCP/IP host (defaults to IPV4 127.0.0.1)
port TCP/IP port (defaults to 3306)
database Database name (defaults to none)
prop A configuration property
val The configuration property's value
* There are more advanced options for other protocols (IPV6,
Named Pipes), replication, failover, load balancing, etc...

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Connector/J URL Examples
jdbc:mysql://
Connect the MySQL server at 127.0.0.1 on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver
Connect the MySQL server dbserver on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
jdbc:mysql://dbserver/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.

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Connector/J URL Examples
jdbc:mysql://
Connect the MySQL server at 127.0.0.1 on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver
Connect the MySQL server dbserver on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
jdbc:mysql://dbserver/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.

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Connector/J URL Examples
jdbc:mysql://
Connect the MySQL server at 127.0.0.1 on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver
Connect the MySQL server dbserver on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
jdbc:mysql://dbserver/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.

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Connector/J URL Examples
jdbc:mysql://
Connect the MySQL server at 127.0.0.1 on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver
Connect the MySQL server dbserver on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
jdbc:mysql://dbserver/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.

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Connector/J URL Examples
jdbc:mysql://
Connect the MySQL server at 127.0.0.1 on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver
Connect the MySQL server dbserver on port 3306 without specifying a
database. You must use Connection.setCatalog("{database}") or
database.table reference in queries.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
jdbc:mysql://dbserver/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.

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Connector/J parameters
Passing in JDBC URL:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing in a Properties file:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
Passing from MysqlDataSource set*() methods:

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Connector/J parameters
Passing in JDBC URL:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing in a Properties file:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
Passing from MysqlDataSource set*() methods:

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Connector/J parameters
Passing in JDBC URL:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing in a Properties file:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
Passing from MysqlDataSource set*() methods:

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Connector/J parameters
Passing in JDBC URL:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing in a Properties file:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
Passing from MysqlDataSource set*() methods:

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Generic JDBC App Example
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
public class DBHello {
public static void main(String[] args)
throws SQLException,ClassNotFoundException,IOException {
Properties dbp = new Properties();
dbp.load(DBHello.class.getClassLoader()
.getResourceAsStream("db.properties"));
Class.forName(dbp.getProperty("class"));
Connection con =
DriverManager.getConnection(dbp.getProperty("url"), dbp);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(dbp.getProperty("versionQuery"));
if (rs.next()) {
System.out.printf("Hello from %sn",rs.getString("version"));
}
rs.close(); st.close(); con.close();
}
}

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Generic JDBC App Example
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
public class DBHello {
public static void main(String[] args)
throws SQLException,ClassNotFoundException,IOException {
Properties dbp = new Properties();
dbp.load(DBHello.class.getClassLoader()
.getResourceAsStream("db.properties"));
Class.forName(dbp.getProperty("class"));
Connection con =
DriverManager.getConnection(dbp.getProperty("url"), dbp);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(dbp.getProperty("versionQuery"));
if (rs.next()) {
System.out.printf("Hello from %sn",rs.getString("version"));
}
rs.close(); st.close(); con.close();
}
}

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Generic JDBC App Example
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
public class DBHello {
public static void main(String[] args)
throws SQLException,ClassNotFoundException,IOException {
Properties dbp = new Properties();
dbp.load(DBHello.class.getClassLoader()
.getResourceAsStream("db.properties"));
Class.forName(dbp.getProperty("class"));
Connection con =
DriverManager.getConnection(dbp.getProperty("url"), dbp);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(dbp.getProperty("versionQuery"));
if (rs.next()) {
System.out.printf("Hello from %sn",rs.getString("version"));
}
rs.close(); st.close(); con.close();
}
}

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Generic JDBC App Example
db.properties configured for MySQL:
# driver
class=com.mysql.jdbc.Driver
# connection url
url=jdbc:mysql://localhost
user=user
password=pwd
# parameters
autoReconnect=true
useConfigs=maxPerformance
# version query
versionQuery=SELECT CONCAT_WS(' ',@@version_comment,@@version,
@@version_compile_os,@@version_compile_machine) AS `version`
Returns:
Hello from MySQL Community Server (GPL) 5.6.23-log Linux x86_64

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Prepared Statements

Security – Better protection from SQL injection attacks,
parameters are sent separately, escaping unnecessary

Performance – Prepared Statements are re-usable.
Interpretation and Optimization happens only once.

More Performance – Combined with Pooling/Caching.

Use them whenever you can.

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Let's do something useful

Runs as a service, records storage capacity to a table

Runs as a report, outputs capacity growth over time

Load JDBC configuration from a Java properties file

PreparedStatement Query with ResultSet

Use and Reuse of PreparedStatement

Batch inserts using addBatch/executeBatch

Dynamic DDL creation
DiskFreeChecker.java
github.com/dbpercona/DiskFreeChecker

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Query
pst=con.prepareStatement(
"SELECT * FROM diskfree WHERE `hostname` = ? AND `when` = ?");
pst.setString(1, hostname);
pst.setTimestamp(2, ts);
rs=pst.executeQuery();
while (rs.next()) {
DiskFreeEntry dfe=new DiskFreeEntry();
dfe.id = rs.getLong("id");
dfe.hostname = rs.getString("hostname");
dfe.fileSystemName = rs.getString("file_system_name");
dfe.totalSpace = rs.getLong("total_space");
dfe.spaceUsed = rs.getLong("space_used");
dfe.spaceFree = rs.getLong("space_free");
dfe.percentageUsed = rs.getBigDecimal("percentage_used");
dfe.fileSystemRoot = rs.getString("file_system_root");
dfe.when = rs.getTimestamp("file_system_root");
diskFreeEntries.put(dfe.fileSystemRoot,dfe);
}
rs.close(); pst.close();

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Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

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Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

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Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

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Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

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Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

45. www.percona.com45
Prepared Statement Reuse
pst = con.prepareStatement("SELECT MAX(`when`) FROM diskfree "
+ "WHERE `when` < ( NOW() - INTERVAL ? SECOND ) "
+ "AND `hostname` = ?");
// then
pst.setBigDecimal(1, secondsBack);
pst.setString(2, hostname);
rs = pst.executeQuery();
if (rs.next()) {
then = rs.getTimestamp(1);
}
rs.close();
// now
pst.setInt(1, 0);
rs = pst.executeQuery();
if (rs.next()) {
now = rs.getTimestamp(1);
}
rs.close();
pst.close();

46. www.percona.com46
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

47. www.percona.com47
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

48. www.percona.com48
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

49. www.percona.com49
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

50. www.percona.com50
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

51. www.percona.com51
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

52. www.percona.com52
Prepared Statement Batches
pst=con.prepareStatement( // prepare insert
"INSERT INTO diskfree (`hostname`,`file_system_name`,"+
"`total_space`,`space_used`,`space_free`,`percentage_used`,"+
"`file_system_root`,`when`) VALUES (?,?,?,?,?,?,?,?)");
for (DiskFreeEntry diskFreeEntry : getDiskFreeEntries()) {
pst.setString ( 1, diskFreeEntry.hostname );
pst.setString ( 2, diskFreeEntry.fileSystemName );
pst.setLong ( 3, diskFreeEntry.totalSpace );
pst.setLong ( 4, diskFreeEntry.spaceUsed );
pst.setLong ( 5, diskFreeEntry.spaceFree );
pst.setBigDecimal( 6, diskFreeEntry.percentageUsed );
pst.setString ( 7, diskFreeEntry.fileSystemRoot );
pst.setTimestamp ( 8, when );
pst.addBatch(); // add to batch
}
int[] inserts=pst.executeBatch(); // execute batch
int totalInserts=0;
for (int i : inserts) totalInserts += i; // compute total

53. www.percona.com53
Prepared Statement Writes
int keepDays=30;
String strKeepDays=dbp.getProperty("keep.days");
if (strKeepDays != null)
keepDays = new Integer(strKeepDays).intValue();
pst = con.prepareStatement(
"DELETE FROM diskfree WHERE `when` < ( NOW() - INTERVAL ? DAY)");
pst.setInt(1, keepDays);
pst.execute();
int updateCount=pst.getUpdateCount();
if (updateCount > 0)
System.out.println("Cleaned up "+updateCount+" old entries.");
else
System.out.println("No old entries to clean up.");
pst.close();

54. www.percona.com54
int keepDays=30;
String strKeepDays=dbp.getProperty("keep.days");
if (strKeepDays != null)
keepDays = new Integer(strKeepDays).intValue();
pst = con.prepareStatement(
"DELETE FROM diskfree WHERE `when` < ( NOW() - INTERVAL ? DAY)");
pst.setInt(1, keepDays);
pst.execute();
int updateCount=pst.getUpdateCount();
if (updateCount > 0)
System.out.println("Cleaned up "+updateCount+" old entries.");
else
System.out.println("No old entries to clean up.");
pst.close();
Prepared Statement Writes

55. www.percona.com55
Prepared Statement Writes
int keepDays=30;
String strKeepDays=dbp.getProperty("keep.days");
if (strKeepDays != null)
keepDays = new Integer(strKeepDays).intValue();
pst = con.prepareStatement(
"DELETE FROM diskfree WHERE `when` < ( NOW() - INTERVAL ? DAY)");
pst.setInt(1, keepDays);
pst.execute();
int updateCount=pst.getUpdateCount();
if (updateCount > 0)
System.out.println("Cleaned up "+updateCount+" old entries.");
else
System.out.println("No old entries to clean up.");
pst.close();

56. www.percona.com56
Prepared Statement Writes
int keepDays=30;
String strKeepDays=dbp.getProperty("keep.days");
if (strKeepDays != null)
keepDays = new Integer(strKeepDays).intValue();
pst = con.prepareStatement(
"DELETE FROM diskfree WHERE `when` < ( NOW() - INTERVAL ? DAY)");
pst.setInt(1, keepDays);
pst.execute();
int updateCount=pst.getUpdateCount();
if (updateCount > 0)
System.out.println("Cleaned up "+updateCount+" old entries.");
else
System.out.println("No old entries to clean up.");
pst.close();

57. www.percona.com57
Prepared Statement Writes
int keepDays=30;
String strKeepDays=dbp.getProperty("keep.days");
if (strKeepDays != null)
keepDays = new Integer(strKeepDays).intValue();
pst = con.prepareStatement(
"DELETE FROM diskfree WHERE `when` < ( NOW() - INTERVAL ? DAY)");
pst.setInt(1, keepDays);
pst.execute();
int updateCount=pst.getUpdateCount();
if (updateCount > 0)
System.out.println("Cleaned up "+updateCount+" old entries.");
else
System.out.println("No old entries to clean up.");
pst.close();

58. www.percona.com58
Performance parameters
Parameter What it does
cachePrepStmts=true If true, cache prepared statements on client side
cacheCallableStmts=true If true, cache prepared stored procedure calls
CacheServerConfiguration=
true
If true, reduces connect queries by caching
server configuration variables.
useLocalSessionState=true If true, reduces setup queries by using the local
session state
elideSetAutoCommits=true If true, only set autocommit if the server doesn't
match the client autocommit setting.
AlwaysSendSetIsolation=
false
If false, doesn't set the transaction isolation level
on connect. Uses server default isolation level
enableQueryTimeouts=false If false, disables query timeouts

59. www.percona.com59
Performance parameters
Parameter What it does
cachePrepStmts=true If true, cache prepared statements on client side
cacheCallableStmts=true If true, cache prepared stored procedure calls
CacheServerConfiguration=
true
If true, reduces connect queries by caching
server configuration variables.
useLocalSessionState=true If true, reduces setup queries by using the local
session state
elideSetAutoCommits=true If true, only set autocommit if the server doesn't
match the client autocommit setting.
AlwaysSendSetIsolation=
false
If false, doesn't set the transaction isolation level
on connect. Uses server default isolation level
enableQueryTimeouts=false If false, disables query timeouts
useConfigs=maxPerformance

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Debugging parameters
Parameter What it does
profileSQL=true If true, log query execution times to the
configured logger.
gatherPerfMetrics=true If true, collect performance metrics to the
configured logger.
useUsageAdvisor=true If true, inefficient use of JDBC and MySQL will
logged to the configured logger as warnings.
logSlowQueries=true If true, 'slow' queries will be logged to the
configured logger (slowQueryThresholdMillis)
explainSlowQueries=true If true, an 'EXPLAIN' statement for slow queries
will be logged to the configured logger.

61. www.percona.com61
Debugging parameters
Parameter What it does
profileSQL=true If true, log query execution times to the
configured logger.
gatherPerfMetrics=true If true, collect performance metrics to the
configured logger.
useUsageAdvisor=true If true, inefficient use of JDBC and MySQL will
logged to the configured logger as warnings.
logSlowQueries=true If true, 'slow' queries will be logged to the
configured logger (slowQueryThresholdMillis)
explainSlowQueries=true If true, an 'EXPLAIN' statement for slow queries
will be logged to the configured logger.
useConfigs=fullDebug

62. www.percona.com62
Other Handy Parameters

autoReconnect

characterEncoding

useInformationSchema

maxRows

63. www.percona.com63
Alternative JDBC Driver

MariaDB Java Client

Maintained-ed by MariaDB team

Fork from Drizzle JDBC

Stable release 1.1.8

Compatible with:

MySQL

Percona Server / PXC

MariaDB

64. www.percona.com64
Alternative JDBC Driver

Pros

Maybe be faster in some cases

It is under active development

Cons

Not as feature rich

Not as mature

65. www.percona.com65
What to learn about next

Connection Pooling

DBCP, C3P0, BoneCP

JNDI / Container Managed

DataSource, Spring

Object Relational Mapping

JPA, Hibernate, Spring

66. www.percona.com66 www.percona.com
THANK YOU