Add YearMonthTimestampType #127

In some legacy schemas it might be required to map a YearMonth to a
Timestamp value, rather than the Date value that we currently support.

This may for example be chosen for easy range comparisions to other
timestamp values without any casting being required.

This change adds such a YearMonthTimestampType. While I think
YearMonthDateType will generally be the preferred type, this at least
should smoothen the transition from a YearMonth modelled as a timestamp
to a YearMonth value.

changelog.txt

@@ -3,6 +3,8 @@ Version 2.7.0 - IN PROGRESS
 
 Add support for JSON column values for Oracle #131
 
+Add YearMonthTimestampType #127
+
 Ability to use PostgreSQLEnumType and EnumArrayType with TypedParameterValue #125
 
 Version 2.6.1 - August 29, 2019

hibernate-types-52/src/main/java/com/vladmihalcea/hibernate/type/basic/YearMonthTimestampType.java

@@ -0,0 +1,45 @@
+package com.vladmihalcea.hibernate.type.basic;
+
+import com.vladmihalcea.hibernate.type.AbstractHibernateType;
+import com.vladmihalcea.hibernate.type.basic.internal.YearMonthTypeDescriptor;
+import com.vladmihalcea.hibernate.type.util.Configuration;
+import org.hibernate.type.descriptor.sql.DateTypeDescriptor;
+import org.hibernate.type.descriptor.sql.TimestampTypeDescriptor;
+
+import java.time.YearMonth;
+
+/**
+ * Maps a Java {@link YearMonth} object to a {@code TIMESTAMP} column type.
+ * <p>
+ *
+ * @author Vlad Mihalcea
+ */
+public class YearMonthTimestampType
+        extends AbstractHibernateType<YearMonth> {
+
+    public static final YearMonthTimestampType INSTANCE = new YearMonthTimestampType();
+
+    public YearMonthTimestampType() {
+        super(
+            TimestampTypeDescriptor.INSTANCE,
+            YearMonthTypeDescriptor.INSTANCE
+        );
+    }
+
+    public YearMonthTimestampType(Configuration configuration) {
+        super(
+            TimestampTypeDescriptor.INSTANCE,
+            YearMonthTypeDescriptor.INSTANCE,
+            configuration
+        );
+    }
+
+    public String getName() {
+        return "yearmonth-timestamp";
+    }
+
+    @Override
+    protected boolean registerUnderJavaType() {
+        return true;
+    }
+}

hibernate-types-52/src/main/java/com/vladmihalcea/hibernate/type/basic/internal/YearMonthTypeDescriptor.java

@@ -3,6 +3,7 @@
 import org.hibernate.type.descriptor.WrapperOptions;
 import org.hibernate.type.descriptor.java.AbstractTypeDescriptor;
 
+import java.sql.Timestamp;
 import java.time.Instant;
 import java.time.YearMonth;
 import java.time.ZoneId;
@@ -49,6 +50,9 @@ public <X> X unwrap(YearMonth value, Class<X> type, WrapperOptions options) {
             Integer numericValue = (value.getYear() * 100) + value.getMonth().getValue();
             return (X) (numericValue);
         }
+        if (Timestamp.class.isAssignableFrom(type)) {
+            return (X) java.sql.Timestamp.valueOf(value.atDay(1).atStartOfDay());
+        }
         if (Date.class.isAssignableFrom(type)) {
             return (X) java.sql.Date.valueOf(value.atDay(1));
         }

hibernate-types-52/src/test/java/com/vladmihalcea/hibernate/type/basic/PostgreSQLYearMonthTimestampTest.java

@@ -0,0 +1,116 @@
+package com.vladmihalcea.hibernate.type.basic;
+
+import com.vladmihalcea.hibernate.type.util.AbstractPostgreSQLIntegrationTest;
+import org.hibernate.Session;
+import org.hibernate.annotations.NaturalId;
+import org.hibernate.annotations.TypeDef;
+import org.junit.Test;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import java.time.YearMonth;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Vlad Mihalcea
+ */
+public class PostgreSQLYearMonthTimestampTest extends AbstractPostgreSQLIntegrationTest {
+
+    @Override
+    protected Class<?>[] entities() {
+        return new Class<?>[]{
+                Book.class
+        };
+    }
+
+    @Test
+    public void test() {
+        doInJPA(entityManager -> {
+            Book book = new Book();
+            book.setIsbn("978-9730228236");
+            book.setTitle("High-Performance Java Persistence");
+            book.setPublishedOn(YearMonth.of(2016, 10));
+
+            entityManager.persist(book);
+        });
+
+        doInJPA(entityManager -> {
+            Book book = entityManager
+                    .unwrap(Session.class)
+                    .bySimpleNaturalId(Book.class)
+                    .load("978-9730228236");
+
+            assertEquals(YearMonth.of(2016, 10), book.getPublishedOn());
+        });
+
+        doInJPA(entityManager -> {
+            Book book = entityManager
+                    .createQuery(
+                            "select b " +
+                                    "from Book b " +
+                                    "where " +
+                                    "   b.title = :title and " +
+                                    "   b.publishedOn = :publishedOn", Book.class)
+                    .setParameter("title", "High-Performance Java Persistence")
+                    .setParameter("publishedOn", YearMonth.of(2016, 10))
+                    .getSingleResult();
+
+            assertEquals("978-9730228236", book.getIsbn());
+        });
+    }
+
+
+    @Entity(name = "Book")
+    @Table(name = "book")
+    @TypeDef(typeClass = YearMonthTimestampType.class, defaultForType = YearMonth.class)
+    public static class Book {
+
+        @Id
+        @GeneratedValue
+        private Long id;
+
+        @NaturalId
+        private String isbn;
+
+        private String title;
+
+        @Column(name = "published_on", columnDefinition = "date")
+        private YearMonth publishedOn;
+
+        public Long getId() {
+            return id;
+        }
+
+        public void setId(Long id) {
+            this.id = id;
+        }
+
+        public String getIsbn() {
+            return isbn;
+        }
+
+        public void setIsbn(String isbn) {
+            this.isbn = isbn;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public YearMonth getPublishedOn() {
+            return publishedOn;
+        }
+
+        public void setPublishedOn(YearMonth publishedOn) {
+            this.publishedOn = publishedOn;
+        }
+    }
+}