Read Committed Test

MyRunner.java

class MyRunner implements Runnable {
    public void run() {
        System.out.println(Thread.currentThread().getName() + ":连接数据库...");
        Connection connection = null;
        try {
            connection = DriverManager.getConnection(RepeatableRead.DB_URL, RepeatableRead.USER, RepeatableRead.PASS);
            connection.setAutoCommit(false);
            //connection.setTransactionIsolation(Connection.TRANSACTION_REPEATABLE_READ);
            connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
            String querySql = "select * from account where id=?";

            synchronized (this) {
                PreparedStatement queryStmt = connection.prepareStatement(querySql);
                queryStmt.setInt(1, 1);
                ResultSet set = queryStmt.executeQuery();
                set.next();
                int amount = set.getInt("amount");
                System.out.println(Thread.currentThread().getName() + ":Amount=" + amount);
                Thread.sleep(1000);
                // 读取了数据，未提交事务。
                String updateSql = "update account set amount=? where id=1";
                PreparedStatement updateStmt = connection.prepareStatement(updateSql);
                updateStmt.setInt(1, amount + 100);
                int count = updateStmt.executeUpdate();
                if (count > 0) {
                    set = queryStmt.executeQuery();
                    set.next();
                    amount = set.getInt("amount");
                    System.out.println(Thread.currentThread().getName() + ":更新成功...|" + amount);
                }
                connection.commit();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}