MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Savepoint;
import java.sql.Statement;

public class MainClass {
    public static void main(String[] args) {
        Connection connection = null;
        Statement statement = null;
        try {
            Class.forName("org.hsqldb.jdbcDriver").newInstance();
            String url = "jdbc:hsqldb:hsqldb\\demoDatabase";
            connection = DriverManager.getConnection(url, "username", "password");
            connection.setAutoCommit(false);

            statement = connection.createStatement();

            String update1 = "UPDATE employees SET email = 'a@b.com' WHERE email = 'a@a.com'";
            statement.executeUpdate(update1);
            Savepoint savepoint1 = connection.setSavepoint("savepoint1");

            String update2 = "UPDATE employees SET email = 'b@b.com' WHERE email = 'b@c.com'";
            statement.executeUpdate(update2);
            Savepoint savepoint2 = connection.setSavepoint("savepoint2");

            String update3 = "UPDATE employees SET email = 'c@c.com' WHERE email = 'c@d.com'";
            statement.executeUpdate(update3);
            Savepoint savepoint3 = connection.setSavepoint("savepoint3");

            String update4 = "UPDATE employees SET email = 'd@d.com' WHERE email = 'd@e.com'";
            statement.executeUpdate(update4);
            Savepoint savepoint4 = connection.setSavepoint("savepoint4");

            String update5 = "UPDATE employees SET email = 'e@e.com' WHERE email = 'e@f.com'";
            statement.executeUpdate(update5);
            Savepoint savepoint5 = connection.setSavepoint("savepoint5");

            connection.rollback(savepoint3);
            connection.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (statement != null) {
                try {
                    statement.close();
                } catch (SQLException e) {
                } // nothing we can do
            }
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                } // nothing we can do
            }
        }
    }
}