jdbc RepeatableReadExample

jdbc-transaction/src/main/java/dev/struchkov/example/transaction/JdbcSimpleExample.java

@@ -6,16 +6,16 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
-public class JdbcExample {
+public class JdbcSimpleExample {
 
-    private static final String INSERT_TRANSACTION_SQL = "INSERT INTO transaction(person_from, person_to, amount) values (?, ?, ?)";
-    private static final String UPDATE_BALANCE_PERSON_FROM_SQL = "UPDATE person SET balance = (balance - ?) WHERE id = ?";
-    private static final String UPDATE_BALANCE_PERSON_TO_SQL = "UPDATE person SET balance = (balance + ?) WHERE id = ?";
+    public static final String INSERT_TRANSACTION_SQL = "INSERT INTO transaction(person_from, person_to, amount) values (?, ?, ?)";
+    public static final String UPDATE_BALANCE_PERSON_FROM_SQL = "UPDATE person SET balance = (balance - ?) WHERE id = ?";
+    public static final String UPDATE_BALANCE_PERSON_TO_SQL = "UPDATE person SET balance = (balance + ?) WHERE id = ?";
 
     public static void main(String[] args) {
-        final JdbcExample jdbcExample = new JdbcExample();
+        final JdbcSimpleExample jdbcSimpleExample = new JdbcSimpleExample();
 //        jdbcExample.runNoTransaction(2L, 1L, 100L);
-        jdbcExample.runWithTransaction(2L, 1L, 100L);
+        jdbcSimpleExample.runWithTransaction(2L, 1L, 100L);
     }
 
     @SneakyThrows
@@ -32,10 +32,9 @@ public class JdbcExample {
         final Connection connection = Repository.getConnection();
 
         try (connection) {
-
             connection.setAutoCommit(false);
             sendMoney(connection, personIdFrom, personIdTo, amount);
-
+            connection.commit();
         } catch (RuntimeException | SQLException e) {
             connection.rollback();
         } finally {

jdbc-transaction/src/main/java/dev/struchkov/example/transaction/RepeatableReadExample.java

@@ -0,0 +1,61 @@
+package dev.struchkov.example.transaction;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class RepeatableReadExample {
+
+    public static final String READ = "SELECT person.balance FROM person WHERE id = ?";
+    public static final String UPDATE = "UPDATE person SET balance = ? WHERE id = ?";
+
+    public static void main(String[] args) {
+        try {
+            final Connection connectionOne = Repository.getConnection();
+            final Connection connectionTwo = Repository.getConnection();
+
+            connectionOne.setAutoCommit(false);
+            connectionTwo.setAutoCommit(false);
+
+            final int transactionLevel = Connection.TRANSACTION_REPEATABLE_READ;
+            connectionOne.setTransactionIsolation(transactionLevel);
+            connectionTwo.setTransactionIsolation(transactionLevel);
+
+            final PreparedStatement readOne = connectionOne.prepareStatement(READ);
+            readOne.setLong(1, 1);
+
+            final PreparedStatement readTwo = connectionTwo.prepareStatement(READ);
+            readTwo.setLong(1, 1);
+
+            final ResultSet resultSetOne = readOne.executeQuery();
+            resultSetOne.next();
+            final long balanceOne = resultSetOne.getLong(1);
+
+            final ResultSet resultSetTwo = readTwo.executeQuery();
+            resultSetTwo.next();
+            final long balanceTwo = resultSetTwo.getLong(1);
+
+            final PreparedStatement updateOne = connectionOne.prepareStatement(UPDATE);
+            updateOne.setLong(1, balanceOne + 10);
+            updateOne.setLong(2, 1);
+            updateOne.execute();
+
+            connectionOne.commit();
+            connectionOne.close();
+
+            final PreparedStatement updateTwo = connectionTwo.prepareStatement(UPDATE);
+            updateTwo.setLong(1, balanceTwo + 5);
+            updateTwo.setLong(2, 1);
+            updateTwo.execute();
+
+            connectionTwo.commit();
+            connectionTwo.close();
+
+        } catch (SQLException e) {
+            System.out.println(e);
+        }
+
+    }
+
+}

jdbc-transaction/src/main/java/dev/struchkov/example/transaction/Repository.java

@@ -1,5 +1,7 @@
 package dev.struchkov.example.transaction;
 
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import java.sql.Connection;
@@ -7,7 +9,8 @@ import java.sql.DriverManager;
 import java.sql.SQLException;
 
 @Slf4j
-public class Repository {
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class Repository {
 
     public static Connection getConnection() {
         try {

pom.xml

@@ -10,6 +10,8 @@
 
     <modules>
         <module>jdbc-transaction</module>
+        <module>hibernate-transaction</module>
+        <module>spring-transaction</module>
     </modules>
 
     <properties>