flash-extensions/flash-ext-data-core/docs/README.md

@@ -112,6 +112,8 @@ public abstract class Repository<T, ID> {
 - `Tx` in the `FlashContext`
 - `TxManager` in the `FlashContext`
 - an annotation processor for `@Transactional`
+- `TxManager.close()` as an `onClose` callback, so stopping the app releases the manager's
+  session factory and connection pool; give the manager a pool you want closed with the app
 
 This makes the data layer composable with Flash's extension system without global state.
 

flash-extensions/flash-ext-data-core/src/main/java/dev/relism/flash/ext/data/DataExtension.java

@@ -34,6 +34,7 @@ public final class DataExtension implements FlashExtension {
 
     @Override
     public void configure(FlashRegistrar<?> app, FlashContext ctx) {
+        ctx.onClose(txManager::close);
         ctx.provide(Tx.class, tx);
         ctx.provide(TxManager.class, txManager);
         if (data != null) ctx.provide(Data.class, data);

flash-extensions/flash-ext-data-core/src/main/java/dev/relism/flash/ext/data/core/TxManager.java

@@ -1,7 +1,11 @@
 package dev.relism.flash.ext.data.core;
 
-public interface TxManager {
+public interface TxManager extends AutoCloseable {
     TxStatus begin(TxDefinition definition);
     void commit(TxStatus status);
     void rollback(TxStatus status);
+
+    /** Releases what this manager was built on, its connection pool included. {@link dev.relism.flash.ext.data.DataExtension} calls it when the app stops. */
+    @Override
+    void close();
 }

flash-extensions/flash-ext-data-hibernate/src/main/java/dev/relism/flash/ext/data/hibernate/HibernateTxManager.java

@@ -3,6 +3,10 @@ package dev.relism.flash.ext.data.hibernate;
 import dev.relism.flash.ext.data.core.*;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+
+import javax.sql.DataSource;
 
 import java.util.Objects;
 
@@ -16,6 +20,24 @@ public class HibernateTxManager implements TxManager {
         this.sf = Objects.requireNonNull(sessionFactory);
     }
 
+    /**
+     * Closes the session factory, then the data source it was given ({@code jakarta.persistence.nonJtaDataSource}
+     * or {@code hibernate.connection.datasource}): Hibernate stops a pool it built itself, never one handed to it.
+     */
+    @Override
+    public void close() {
+        ConnectionProvider connections = sf.unwrap(SessionFactoryImplementor.class).getServiceRegistry().getService(ConnectionProvider.class);
+        DataSource ds = connections != null && connections.isUnwrappableAs(DataSource.class) ? connections.unwrap(DataSource.class) : null;
+        sf.close();
+        if (ds instanceof AutoCloseable closeable) {
+            try {
+                closeable.close();
+            } catch (Exception e) {
+                throw new IllegalStateException("Failed to close the data source", e);
+            }
+        }
+    }
+
     @Override
     public TxStatus begin(TxDefinition definition) {
         return switch (definition.propagation()) {

flash-extensions/flash-ext-data-hibernate/src/test/java/dev/relism/flash/ext/data/hibernate/HibernateTxManagerCloseTest.java

@@ -0,0 +1,48 @@
+package dev.relism.flash.ext.data.hibernate;
+
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.AvailableSettings;
+import org.junit.jupiter.api.Test;
+
+import javax.sql.DataSource;
+import java.io.PrintWriter;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.logging.Logger;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class HibernateTxManagerCloseTest {
+
+    /** Stands in for a pool: closeable, and it records being closed. */
+    static final class Pool implements DataSource, AutoCloseable {
+        boolean closed;
+        @Override public Connection getConnection() throws SQLException { return DriverManager.getConnection("jdbc:h2:mem:tx-close;DB_CLOSE_DELAY=-1"); }
+        @Override public Connection getConnection(String user, String password) throws SQLException { return getConnection(); }
+        @Override public void close() { closed = true; }
+        @Override public <T> T unwrap(Class<T> type) { throw new UnsupportedOperationException(); }
+        @Override public boolean isWrapperFor(Class<?> type) { return false; }
+        @Override public PrintWriter getLogWriter() { return null; }
+        @Override public void setLogWriter(PrintWriter out) {}
+        @Override public void setLoginTimeout(int seconds) {}
+        @Override public int getLoginTimeout() { return 0; }
+        @Override public Logger getParentLogger() { throw new UnsupportedOperationException(); }
+    }
+
+    @Test
+    void closingTheManagerClosesTheDataSourceHibernateWasGiven() {
+        Pool pool = new Pool();
+        SessionFactory sf = new MetadataSources(new StandardServiceRegistryBuilder()
+                .applySetting(AvailableSettings.JAKARTA_NON_JTA_DATASOURCE, pool)
+                .applySetting(AvailableSettings.DIALECT, "org.hibernate.dialect.H2Dialect")
+                .build()).buildMetadata().buildSessionFactory();
+
+        new HibernateTxManager(sf).close();
+
+        assertTrue(sf.isClosed());
+        assertTrue(pool.closed);
+    }
+}

flash-extensions/flash-ext-data-jdbc/src/main/java/dev/relism/flash/ext/data/jdbc/JdbcTxManager.java

@@ -17,6 +17,18 @@ public class JdbcTxManager implements TxManager {
         this.ds = Objects.requireNonNull(ds);
     }
 
+    /** Closes the data source when it is closeable, as a pool is; a plain {@code DataSource} holds nothing to release. */
+    @Override
+    public void close() {
+        if (ds instanceof AutoCloseable closeable) {
+            try {
+                closeable.close();
+            } catch (Exception e) {
+                throw new IllegalStateException("Failed to close the data source", e);
+            }
+        }
+    }
+
     @Override
     public TxStatus begin(TxDefinition definition) {
         return switch (definition.propagation()) {

flash-extensions/flash-ext-data-jdbc/src/test/java/dev/relism/flash/ext/data/jdbc/JdbcTxManagerCloseTest.java

@@ -0,0 +1,20 @@
+package dev.relism.flash.ext.data.jdbc;
+
+import com.zaxxer.hikari.HikariDataSource;
+import dev.relism.flash.ext.data.DataExtension;
+import dev.relism.flash.extension.FlashApp;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class JdbcTxManagerCloseTest {
+
+    /** A pool outlives its app unless someone closes it; the data extension does, once requests have drained. */
+    @Test
+    void stoppingTheAppClosesThePool() {
+        HikariDataSource pool = new HikariDataSource();
+        pool.setJdbcUrl(TestDataSource.URL);
+        FlashApp.create(0).install(new DataExtension(new JdbcTxManager(pool))).start().stop().join();
+        assertTrue(pool.isClosed());
+    }
+}