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Struchkov Mark 2022-07-24 08:40:27 +03:00
parent 8547eee701
commit b4c0d30bba
3 changed files with 161 additions and 0 deletions
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49
jdbc-transaction/src/main/java/dev/struchkov/example/transaction/problems/DirtyReadExample.java Normal file
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package dev.struchkov.example.transaction.problems;
import dev.struchkov.example.transaction.Repository;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DirtyReadExample {
public static void main(String[] args) throws SQLException, InterruptedException {
try (
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED);
statement.execute("UPDATE person SET balance = 100000 WHERE id = 1");
new OtherTransaction().start();
Thread.sleep(2000);
connection.rollback();
}
}
static class OtherTransaction extends Thread {
@Override
public void run() {
try (
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED);
final ResultSet resultSet = statement.executeQuery("SELECT * FROM person WHERE id = 1");
while (resultSet.next()) {
System.out.println(resultSet.getString("balance"));
}
} catch (SQLException e) {
System.out.println(e.getMessage());
}
}
}
}

56
jdbc-transaction/src/main/java/dev/struchkov/example/transaction/problems/NonRepeatableRead.java Normal file
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package dev.struchkov.example.transaction.problems;
import dev.struchkov.example.transaction.Repository;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class NonRepeatableRead {
public static void main(String[] args) {
try(
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
final ResultSet resultSet = statement.executeQuery("SELECT * FROM person WHERE id = 1");
while (resultSet.next()) {
System.out.println(resultSet.getString("balance"));
}
new OtherTransaction().start();
Thread.sleep(2000);
final ResultSet resultSetTwo = statement.executeQuery("SELECT * FROM person WHERE id = 1");
while (resultSetTwo.next()) {
System.out.println(resultSetTwo.getString("balance"));
}
} catch (SQLException | InterruptedException e) {
throw new RuntimeException(e);
}
}
static class OtherTransaction extends Thread {
@Override
public void run() {
try (
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
statement.executeUpdate("UPDATE person SET balance = 100000 WHERE id = 1");
connection.commit();
} catch (SQLException e) {
System.out.println(e.getMessage());
}
}
}
}

56
jdbc-transaction/src/main/java/dev/struchkov/example/transaction/problems/PhantomRead.java Normal file
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package dev.struchkov.example.transaction.problems;
import dev.struchkov.example.transaction.Repository;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class PhantomRead {
public static void main(String[] args) {
try(
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
final ResultSet resultSet = statement.executeQuery("SELECT count(*) FROM person");
while (resultSet.next()) {
System.out.println(resultSet.getInt(1));
}
new OtherTransaction().start();
Thread.sleep(2000);
final ResultSet resultSetTwo = statement.executeQuery("SELECT count(*) FROM person");
while (resultSetTwo.next()) {
System.out.println(resultSetTwo.getInt(1));
}
} catch (SQLException | InterruptedException e) {
throw new RuntimeException(e);
}
}
static class OtherTransaction extends Thread {
@Override
public void run() {
try (
final Connection connection = Repository.getConnection();
final Statement statement = connection.createStatement()
) {
connection.setAutoCommit(false);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
statement.executeUpdate("INSERT INTO person(name, balance) values ('test', 100)");
connection.commit();
} catch (SQLException e) {
System.out.println(e.getMessage());
}
}
}
}