Mappers for database date/time/timestamps. (#1485)

* Mappers for database date/time/timestamps.

Signed-off-by: Tomas Kraus <Tomas.Kraus@oracle.com>

dbclient/common/src/main/java/io/helidon/dbclient/common/DbClientMapperProvider.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.dbclient.common;
+
+import java.sql.Timestamp;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.util.Calendar;
+import java.util.Collections;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+import io.helidon.common.mapper.Mapper;
+import io.helidon.common.mapper.spi.MapperProvider;
+
+/**
+ * Java Service loader service to get database types mappers.
+ */
+public class DbClientMapperProvider implements MapperProvider {
+
+    /**
+     * Mappers index {@code [Class<SOURCE>, Class<TARGET>] -> Mapper<SOURCE, TARGET>}.
+     */
+    private static final Map<Class<?>, Map<Class<?>, Mapper<?, ?>>> MAPPERS = initMappers();
+
+    private static Map<Class<?>, Map<Class<?>, Mapper<?, ?>>> initMappers() {
+        // All mappers index
+        Map<Class<?>, Map<Class<?>, Mapper<?, ?>>> mappers = new HashMap<>(3);
+        // * Mappers for java.sql.Timestamp source
+        Map<Class<?>, Mapper<Timestamp, Object>> sqlTimestampMap = new HashMap<>(4);
+        //   - Mapper for java.sql.Timestamp to java.util.Date
+        sqlTimestampMap.put(
+                Date.class,
+                source -> source);
+        //   - Mapper for java.sql.Timestamp to java.time.LocalDateTime
+        sqlTimestampMap.put(
+                LocalDateTime.class,
+                (Timestamp source) -> source != null
+                        ? source.toLocalDateTime()
+                        : null);
+        //   - Mapper for java.sql.Timestamp to java.time.ZonedDateTime
+        sqlTimestampMap.put(
+                ZonedDateTime.class,
+                (Timestamp source) -> source != null
+                        ? ZonedDateTime.ofInstant(source.toInstant(), ZoneOffset.UTC)
+                        : null);
+        //   - Mapper for java.sql.Timestamp to java.util.Calendar
+        sqlTimestampMap.put(
+                Calendar.class,
+                DbClientMapperProvider::sqlTimestampToGregorianCalendar);
+        //   - Mapper for java.sql.Timestamp to java.util.GregorianCalendar
+        sqlTimestampMap.put(
+                GregorianCalendar.class,
+                DbClientMapperProvider::sqlTimestampToGregorianCalendar);
+        mappers.put(
+                Timestamp.class,
+                Collections.unmodifiableMap(sqlTimestampMap));
+        // * Mappers for java.sql.Date source
+        Map<Class<?>, Mapper<java.sql.Date, Object>> sqlDateMap = new HashMap<>(2);
+        //   - Mapper for java.sql.Date to java.util.Date
+        sqlDateMap.put(
+                Date.class,
+                source -> source);
+        //   - Mapper for java.sql.Date to java.time.LocalDate
+        sqlDateMap.put(
+                LocalDate.class,
+                (java.sql.Date source) -> source != null
+                        ? source.toLocalDate()
+                        : null);
+        mappers.put(
+                java.sql.Date.class,
+                Collections.unmodifiableMap(sqlDateMap));
+        // * Mappers for java.sql.Time source
+        Map<Class<?>, Mapper<java.sql.Time, Object>> sqlTimeMap = new HashMap<>(2);
+        //   - Mapper for java.sql.Time to java.util.Date
+        sqlTimeMap.put(
+                Date.class,
+                source -> source);
+        //   - Mapper for java.sql.Time to java.time.LocalTime
+        sqlTimeMap.put(
+                LocalTime.class,
+                (java.sql.Time source) -> source != null
+                        ? source.toLocalTime()
+                        : null);
+        mappers.put(
+                java.sql.Time.class,
+                Collections.unmodifiableMap(sqlTimeMap));
+        return Collections.unmodifiableMap(mappers);
+    }
+
+    @Override
+    public <SOURCE, TARGET> Optional<Mapper<?, ?>> mapper(Class<SOURCE> sourceClass, Class<TARGET> targetClass) {
+        Map<Class<?>, Mapper<?, ?>> targetMap = MAPPERS.get(sourceClass);
+        if (targetMap == null) {
+            return Optional.empty();
+        }
+        Mapper<?, ?> mapper = targetMap.get(targetClass);
+        return mapper == null ? Optional.empty() : Optional.of(mapper);
+    }
+
+    /**
+     * Maps {@link java.sql.Timestamp} to {@link java.util.Calendar} with zone set to UTC.
+     */
+    private static GregorianCalendar sqlTimestampToGregorianCalendar(Timestamp source) {
+        return source != null
+                ? GregorianCalendar.from(ZonedDateTime.ofInstant(source.toInstant(), ZoneOffset.UTC))
+                : null;
+    }
+
+}

dbclient/common/src/main/java/module-info.java

@@ -26,4 +26,6 @@
     requires transitive io.helidon.dbclient;
 
     exports io.helidon.dbclient.common;
+
+    provides io.helidon.common.mapper.spi.MapperProvider with io.helidon.dbclient.common.DbClientMapperProvider;
 }

dbclient/common/src/main/resources/META-INF/services/io.helidon.common.mapper.spi.MapperProvider

@@ -0,0 +1,17 @@
+#
+# Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+io.helidon.dbclient.common.DbClientMapperProvider

dbclient/common/src/test/java/io/helidon/dbclient/common/mapper/MapperTest.java

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.dbclient.common.mapper;
+
+import java.sql.Timestamp;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.time.temporal.ChronoField;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+
+import io.helidon.common.mapper.MapperManager;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+/**
+ * Test database types {@link Mapper}s. 
+ */
+public class MapperTest {
+
+    private static MapperManager mm;
+
+    @BeforeAll
+    public static void init() {
+        mm = MapperManager.create();
+    }
+
+    /**
+     * Current date with time set to 00:00:00.
+     *
+     * @return current date with time set to 00:00:00
+     */
+    private static OffsetDateTime currentDate() {
+        return OffsetDateTime.now()
+                .with(ChronoField.HOUR_OF_DAY, 0)
+                .with(ChronoField.MINUTE_OF_HOUR, 0)
+                .with(ChronoField.SECOND_OF_MINUTE, 0)
+                .with(ChronoField.NANO_OF_SECOND, 0);  
+    }
+
+    /**
+     * Current time with date set to 1. 1. 1970 (epoch).
+     *
+     * @return current time with date set to 1. 1. 1970 (epoch)
+     */
+    private static OffsetDateTime currentTime() {
+        return OffsetDateTime.now()
+                .with(ChronoField.YEAR, 1970)
+                .with(ChronoField.MONTH_OF_YEAR, 1)
+                .with(ChronoField.DAY_OF_MONTH, 1);
+    }
+
+    @Test
+    public void testSqlDateToLocalDate() {
+        OffsetDateTime dt = currentDate();
+        java.sql.Date source = new java.sql.Date(dt.toInstant().toEpochMilli());
+        LocalDate target = mm.map(source, java.sql.Date.class, LocalDate.class);
+        assertThat(target.toEpochSecond(LocalTime.MIN, dt.getOffset()), is(source.getTime()/1000));
+    }    
+
+    @Test
+    public void testSqlDateToUtilDate() {
+        OffsetDateTime dt = OffsetDateTime.now();
+        java.sql.Date source = new java.sql.Date(dt.toInstant().toEpochMilli());
+        Date target = mm.map(source, java.sql.Date.class, Date.class);
+        assertThat(target.getTime(), is(source.getTime()));
+    }    
+
+    @Test
+    public void testSqlTimeToLocalTime() {
+        OffsetDateTime dt = currentTime();
+        java.sql.Time source = new java.sql.Time(dt.toInstant().toEpochMilli());
+        LocalTime target = mm.map(source, java.sql.Time.class, LocalTime.class);
+        assertThat(target.toEpochSecond(LocalDate.EPOCH, dt.getOffset()), is(source.getTime()/1000));
+    }    
+
+    @Test
+    public void testSqlTimeToUtilDate() {
+        OffsetDateTime dt = OffsetDateTime.now();
+        java.sql.Time source = new java.sql.Time(dt.toInstant().toEpochMilli());
+        Date target = mm.map(source, java.sql.Time.class, Date.class);
+        assertThat(target.getTime(), is(source.getTime()));
+    }    
+
+    @Test
+    public void testSqlTimestampToGregorianCalendar() {
+        Timestamp source = new Timestamp(System.currentTimeMillis());
+        GregorianCalendar target = mm.map(source, Timestamp.class, GregorianCalendar.class);
+        assertThat(target.getTimeInMillis(), is(source.getTime()));
+    }
+
+    @Test
+    public void testSqlTimestampToCalendar() {
+        Timestamp source = new Timestamp(System.currentTimeMillis());
+        Calendar target = mm.map(source, Timestamp.class, Calendar.class);
+        assertThat(target.getTimeInMillis(), is(source.getTime()));
+    }
+
+    @Test
+    public void testSqlTimestampToLocalDateTime() {
+        // Need to know time zone too.
+        OffsetDateTime dt = OffsetDateTime.now();
+        Timestamp source = new Timestamp(dt.toInstant().toEpochMilli());
+        LocalDateTime target = mm.map(source, Timestamp.class, LocalDateTime.class);
+        assertThat(target.atOffset(dt.getOffset()).toInstant().toEpochMilli(), is(source.getTime()));
+    }
+
+    @Test
+    public void testSqlTimestampToUtilDate() {
+        Timestamp source = new Timestamp(System.currentTimeMillis());
+        Date target = mm.map(source, Timestamp.class, Date.class);
+        assertThat(target.getTime(), is(source.getTime()));
+    }
+
+    @Test
+    public void testSqlTimestampToZonedDateTime() {
+        Timestamp source = new Timestamp(System.currentTimeMillis());
+        ZonedDateTime target = mm.map(source, Timestamp.class, ZonedDateTime.class);
+        assertThat(target.toInstant().toEpochMilli(), is(source.getTime()));
+    }
+
+}