JDBC Isolation Example
In this tutorial you will learn the levels of isolation in JDBC and how to use them in JDBC
In this tutorial you will learn the levels of isolation in JDBC and how to use them in JDBCJDBC Isolation Level Example
JDBC isolation level represents that, how a database maintains its interiority against the problem such as dirty reads, non-repeatable reads and phantom reads that occurs during concurrent transactions. You can get the current isolation level by using method getTransactionIsolation(), and also set the isolation by setTransactionIsolation(int isolationlevelconstant) methods respectively.
Types of Isolation level
1. TRANSACTION_READ_UNCOMMITTED- It allows non-repeatable reads, dirty reads and phantom reads to occur
2. TRANSACTION_READ_COMMITTED- It ensures only those data can be read which is committed.
3. TRANSACTION_REPEATABLE_READ- It is closer to serializable but phantom reads are also possible.
4. TRANSACTION_SERIALIZABLE- In this level of isolation dirty reads, non-repeatable reads, and phantom reads are prevented.
Integer Value for Isolation level
TRANSACTION_NONE = 0
TRANSACTION_READ_COMMITTED = 2
TRANSACTION_READ_UNCOMMITTED = 1
TRANSACTION_REPEATABLE_READ = 4
TRANSACTION_SERIALIZABLE = 8
At first create table named student in MySql database and inset values into it as.
CREATE TABLE student (
RollNo int(9) PRIMARY KEY NOT NULL,
Name tinytext NOT NULL,
Course varchar(25) NOT NULL,
Address text
);
Insert Value Into student table
INSERT INTO student VALUES(1, 'Vinay', 'MCA', 'Delhi') ;
TransactionIsolationExample.java
package roseindia.net;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class TransactionIsolationExample {
public static void main(String[] args) throws SQLException {
Connection con = null; // connection reference variable for getting
// connection
Statement stmt = null; // Statement reference variable for query
// Execution
ResultSet rs = null; // ResultSet reference variable for saving query
// result
String conUrl = "jdbc:mysql://localhost:3306/";
String driverName = "com.mysql.jdbc.Driver";
String databaseName = "student";
String usrName = "root";
String usrPass = "root";
try {
// Loading Driver
Class.forName(driverName);
} catch (ClassNotFoundException e) {
System.out.println(e.toString());
}
try {
// Getting Connection
con = DriverManager.getConnection(conUrl + databaseName, usrName,
usrPass);
// Creating Statement for query execution
stmt = con.createStatement();
// creating Query String
String query = "SELECT * FROM student";
// excecuting query
rs = stmt.executeQuery(query);
while (rs.next()) {
// Didplaying data of tables
System.out.println("Roll No " + rs.getInt("RollNo") + ", Name "
+ rs.getString("Name") + ", Course "
+ rs.getString("Course") + ", Address "
+ rs.getString("Address"));
}
DatabaseMetaData dbMetaData = con.getMetaData();
if (dbMetaData
.supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE)) {
System.out.println("Transaction Isolation level= "
+ con.getTransactionIsolation());
// Setting Transaction Isolation Level
// You can set Its String Value or its int value
con.setTransactionIsolation(2);
}
} catch (Exception e) {
System.out.println(e.toString());
} finally {
// Closing connection
con.close();
stmt.close();
rs.close();
}
}
}
When you run this application it will display message as shown below:| Roll No 1, Name Vinay, Course MCA, Address
Delhi Transaction Isolation level= 4 |
