Using MySQL with Java
Q2 2014
David Bennett
QA Engineer
April 15th, 2015
Who are you?
●
Java Experts, Intermediate, Beginners
●
MySQL Experts, Intermediate, Beginners
●
Developers, DBAs, System Admins
●
Just interested
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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
●
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Dave Bennett
www.percona.com
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?
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●
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/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 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/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 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/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 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/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 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/mydb
Connect the MySQL server dbserver on port 3306 using database mydb.
jdbc:mysql://dbserver:3307/mydb
Connect the MySQL server dbserver on port 3307 using database mydb.
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Connector/J parameters
Passing in JDBC URL:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
Passing in a Properties file:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing from MysqlDataSource set*() methods:
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
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Connector/J parameters
Passing in JDBC URL:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
Passing in a Properties file:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing from MysqlDataSource set*() methods:
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
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Connector/J parameters
Passing in JDBC URL:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
Passing in a Properties file:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing from MysqlDataSource set*() methods:
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
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Connector/J parameters
Passing in JDBC URL:
Connection con = DriverManager.getConnection(
"jdbc:mysql://host/db?autoReconnect=true&useConfigs=maxPerformance"
);
Passing in a Properties file:
dbProperties.load(MyClass.class.getClassLoader()
.getResourceAsStream("db.properties"));
Connection con =
DriverManager.getConnection("jdbc:mysql://", dbProperties);
Passing from MysqlDataSource set*() methods:
MysqlDataSource mds=new MysqlDataSource();
mds.setUrl("jdbc:mysql://");
mds.setUser("user");
mds.setPassword("pwd");
mds.setAutoReconnect(true);
mds.setUseConfigs("maxPerformance");
Connection con=mds.getConnection();
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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 %s\n",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 %s\n",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 %s\n",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
DiskFreeChecker.java
github.com/dbpercona/DiskFreeChecker
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●
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
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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();
49
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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();
50
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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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
51
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
52
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
53
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
54
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
55
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
56
{
add to batch
execute batch
compute total
www.percona.com
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();
//
}
int[] inserts=pst.executeBatch();
//
int totalInserts=0;
for (int i : inserts) totalInserts += i;
//
57
{
add to batch
execute batch
compute total
www.percona.com
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.com
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();
59
www.percona.com
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();
60
www.percona.com
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();
61
www.percona.com
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();
62
www.percona.com
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= If true, reduces connect queries by caching
server configuration variables.
true
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
63
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Performance parameters
useConfigs=maxPerformance
64
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
www.percona.com
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.
65
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Debugging parameters
useConfigs=fullDebug
66
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.
www.percona.com
Other Handy Parameters
67
●
autoReconnect
●
characterEncoding
●
useInformationSchema
●
maxRows
www.percona.com
Alternative JDBC Driver
●
68
MariaDB Java Client

Maintained-ed by MariaDB team

Fork from Drizzle JDBC

Stable release 1.1.8

Compatible with:
✔
MySQL
✔
Percona Server / PXC
✔
MariaDB
www.percona.com
Alternative JDBC Driver
Pros

Maybe be faster in some cases

It is under active development

Cons

Not as feature rich

Not as mature
●
69
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What to learn about next
●
Connection Pooling
●
●
JNDI / Container Managed
●
●
DataSource, Spring
Object Relational Mapping
●
70
DBCP, C3P0, BoneCP
JPA, Hibernate, Spring
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THANK YOU
71
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