Storing of commands whilst shuttered is now idempotent

Author: amckenzie

CHANGELOG.md

@@ -5,6 +5,10 @@ on [Keep a CHANGELOG](http://keepachangelog.com/). This project adheres to
 
 ## [Unreleased]
 
+## [6.0.17] - 2019-10-04
+### Changed
+- Storing of Commands whilst shuttered is now idempotent 
+
 ## [6.0.16] - 2018-09-23
 ### Changed
 - Renamed ValidateCatchupCommand to VerifyCatchupCommand

framework-system/shuttering-persistence/src/main/java/uk/gov/justice/services/shuttering/persistence/StoredCommandRepository.java

@@ -19,10 +19,15 @@
 import javax.inject.Inject;
 import javax.sql.DataSource;
 
+import org.slf4j.Logger;
+
 public class StoredCommandRepository {
 
     private static final String SELECT_STORED_COMMAND_SQL = "SELECT envelope_id, command_json_envelope, destination, date_received FROM stored_command";
-    private static final String INSERT_STORED_COMMAND_SQL = "INSERT into stored_command (envelope_id, command_json_envelope, destination, date_received) VALUES (?, ?, ?, ?)";
+    private static final String INSERT_STORED_COMMAND_SQL = "INSERT into stored_command " +
+            "(envelope_id, command_json_envelope, destination, date_received) " +
+            "VALUES (?, ?, ?, ?) " +
+            "ON CONFLICT DO NOTHING";
     private static final String TRUNCATE_STORED_COMMAND_SQL = "TRUNCATE stored_command";
     private static final String DELETE_STORED_COMMAND_SQL = "DELETE FROM stored_command WHERE envelope_id = ?";
 
@@ -35,6 +40,9 @@ public class StoredCommandRepository {
     @Inject
     private JdbcResultSetStreamer jdbcResultSetStreamer;
 
+    @Inject
+    private Logger logger;
+
     public Stream<StoredCommand> streamStoredCommands() {
 
         final DataSource dataSource = systemJdbcDataSourceProvider.getDataSource();
@@ -76,7 +84,11 @@ public void save(final StoredCommand storedCommand) {
             preparedStatement.setString(2, storedCommand.getCommandJsonEnvelope());
             preparedStatement.setString(3, storedCommand.getDestination());
             preparedStatement.setTimestamp(4, toSqlTimestamp(storedCommand.getDateReceived()));
-            preparedStatement.executeUpdate();
+            final int rowsChanged = preparedStatement.executeUpdate();
+
+            if (rowsChanged == 0) {
+               logger.warn(format("Command with id '%s' not inserted into stored_command table. Command with that id already exists", storedCommand.getEnvelopeId()));
+            }
 
         } catch (final SQLException e) {
             throw new StoredCommandPersistenceException("Failed to insert stored command", e);

framework-system/shuttering-persistence/src/test/java/uk/gov/justice/services/shuttering/persistence/StoredCommandRepositoryIT.java

@@ -1,10 +1,12 @@
 package uk.gov.justice.services.shuttering.persistence;
 
+import static java.util.UUID.fromString;
 import static java.util.UUID.randomUUID;
 import static java.util.stream.Collectors.toList;
 import static org.hamcrest.CoreMatchers.hasItem;
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import uk.gov.justice.services.common.util.UtcClock;
@@ -16,6 +18,7 @@
 
 import java.time.ZonedDateTime;
 import java.util.List;
+import java.util.UUID;
 import java.util.stream.Stream;
 
 import javax.sql.DataSource;
@@ -26,6 +29,7 @@
 import org.mockito.Mock;
 import org.mockito.Spy;
 import org.mockito.runners.MockitoJUnitRunner;
+import org.slf4j.Logger;
 
 @RunWith(MockitoJUnitRunner.class)
 public class StoredCommandRepositoryIT {
@@ -39,6 +43,9 @@ public class StoredCommandRepositoryIT {
     @Spy
     private JdbcResultSetStreamer jdbcResultSetStreamer = new JdbcResultSetStreamer();
 
+    @Mock
+    private Logger logger;
+
     @InjectMocks
     private StoredCommandRepository storedCommandRepository;
 
@@ -110,4 +117,31 @@ public void shouldDeleteShutteredCommand() throws Exception {
         assertThat(storedCommands, hasItem(storedCommand_1));
         assertThat(storedCommands, hasItem(storedCommand_3));
     }
+
+    @Test
+    public void shouldBeIdempotentWhenSaving() throws Exception {
+
+        final DataSource systemDataSource = new TestJdbcDataSourceProvider().getSystemDataSource("framework");
+
+        when(systemJdbcDataSourceProvider.getDataSource()).thenReturn(systemDataSource);
+
+        storedCommandRepository.deleteAll();
+
+        final UUID envelopeId = fromString("0b305815-f251-481d-9a69-2ff60c3a88ca");
+        final StoredCommand storedCommand = new StoredCommand(envelopeId, "command envelope 1", "destination 1", new UtcClock().now());
+
+        storedCommandRepository.save(storedCommand);
+
+
+        final Stream<StoredCommand> secondShutteredCommandStream = storedCommandRepository.streamStoredCommands();
+        final List<StoredCommand> storedCommands = secondShutteredCommandStream.collect(toList());
+
+        assertThat(storedCommands.size(), is(1));
+
+        assertThat(storedCommands, hasItem(storedCommand));
+
+        storedCommandRepository.save(storedCommand);
+
+        verify(logger).warn("Command with id '0b305815-f251-481d-9a69-2ff60c3a88ca' not inserted into stored_command table. Command with that id already exists");
+    }
 }