#1656 Support for mapping between String and java.time Duration, Period, Instant

documentation/src/main/asciidoc/mapstruct-reference-guide.asciidoc

@@ -944,6 +944,8 @@ public interface CarMapper {
 
 * Between `java.time.ZonedDateTime`, `java.time.LocalDateTime`, `java.time.LocalDate`, `java.time.LocalTime` from Java 8 Date-Time package and `String`. A format string as understood by `java.text.SimpleDateFormat` can be specified via the `dateFormat` option (see above).
 
+* Between `java.time.Instant`, `java.time.Duration`, `java.time.Period` from Java 8 Date-Time package and `String` using the `parse` method in each class to map from `String` and using `toString` to map into `String`.
+
 * Between `java.time.ZonedDateTime` from Java 8 Date-Time package and `java.util.Date` where, when mapping a `ZonedDateTime` from a given `Date`, the system default timezone is used.
 
 * Between `java.time.LocalDateTime` from Java 8 Date-Time package and `java.util.Date` where timezone UTC is used as the timezone.

processor/src/main/java/org/mapstruct/ap/internal/conversion/Conversions.java

@@ -9,10 +9,12 @@ import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.sql.Time;
 import java.sql.Timestamp;
+import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.Period;
 import java.time.ZonedDateTime;
 import java.util.Calendar;
 import java.util.Currency;
@@ -171,8 +173,8 @@ public class Conversions {
         registerToStringConversion( Boolean.class );
         register( char.class, String.class, new CharToStringConversion() );
         register( Character.class, String.class, new CharWrapperToStringConversion() );
-        register( BigInteger.class, String.class, new BigIntegerToStringConversion( ) );
-        register( BigDecimal.class, String.class, new BigDecimalToStringConversion( ) );
+        register( BigInteger.class, String.class, new BigIntegerToStringConversion() );
+        register( BigDecimal.class, String.class, new BigDecimalToStringConversion() );
 
         registerJodaConversions();
 
@@ -217,6 +219,9 @@ public class Conversions {
         register( LocalDate.class, String.class, new JavaLocalDateToStringConversion() );
         register( LocalDateTime.class, String.class, new JavaLocalDateTimeToStringConversion() );
         register( LocalTime.class, String.class, new JavaLocalTimeToStringConversion() );
+        register( Instant.class, String.class, new StaticParseToStringConversion() );
+        register( Period.class, String.class, new StaticParseToStringConversion() );
+        register( Duration.class, String.class, new StaticParseToStringConversion() );
 
         // Java 8 to Date
         register( ZonedDateTime.class, Date.class, new JavaZonedDateTimeToDateConversion() );

processor/src/main/java/org/mapstruct/ap/internal/conversion/StaticParseToStringConversion.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.internal.conversion;
+
+import java.util.Set;
+
+import org.mapstruct.ap.internal.model.common.ConversionContext;
+import org.mapstruct.ap.internal.model.common.Type;
+import org.mapstruct.ap.internal.util.Collections;
+
+/**
+ * Handles conversion between a target type <tt>T</tt> and {@link String},
+ * where {@code T#parse(String)} and {@code T#toString} are inverse operations.
+ * The {@link ConversionContext#getTargetType()} is used as the from target type <tt>T</tt>.
+ */
+public class StaticParseToStringConversion extends SimpleConversion {
+
+    @Override
+    protected String getToExpression(ConversionContext conversionContext) {
+        return "<SOURCE>.toString()";
+    }
+
+    @Override
+    protected String getFromExpression(ConversionContext conversionContext) {
+        return conversionContext.getTargetType().createReferenceName() + ".parse( <SOURCE> )";
+    }
+
+    @Override
+    protected Set<Type> getFromConversionImportTypes(ConversionContext conversionContext) {
+        return Collections.asSet( conversionContext.getTargetType() );
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/conversion/java8time/Java8TimeConversionTest.java

@@ -5,12 +5,12 @@
  */
 package org.mapstruct.ap.test.conversion.java8time;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
+import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.Period;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.Calendar;
@@ -23,6 +23,8 @@ import org.mapstruct.ap.testutil.IssueKey;
 import org.mapstruct.ap.testutil.WithClasses;
 import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * Tests for conversions to/from Java 8 date and time types.
  */
@@ -99,7 +101,7 @@ public class Java8TimeConversionTest {
         Target target = new Target();
         target.setZonedDateTime( dateTimeAsString );
         ZonedDateTime sourceDateTime =
-                        ZonedDateTime.of( java.time.LocalDateTime.of( 2014, 1, 1, 0, 0 ), ZoneId.of( "UTC" ) );
+            ZonedDateTime.of( java.time.LocalDateTime.of( 2014, 1, 1, 0, 0 ), ZoneId.of( "UTC" ) );
 
         Source src = SourceTargetMapper.INSTANCE.targetToSourceDateTimeMapped( target );
         assertThat( src ).isNotNull();
@@ -112,7 +114,7 @@ public class Java8TimeConversionTest {
         Target target = new Target();
         target.setLocalDateTime( dateTimeAsString );
         LocalDateTime sourceDateTime =
-                        LocalDateTime.of( 2014, 1, 1, 0, 0, 0 );
+            LocalDateTime.of( 2014, 1, 1, 0, 0, 0 );
 
         Source src = SourceTargetMapper.INSTANCE.targetToSourceLocalDateTimeMapped( target );
         assertThat( src ).isNotNull();
@@ -125,7 +127,7 @@ public class Java8TimeConversionTest {
         Target target = new Target();
         target.setLocalDate( dateTimeAsString );
         LocalDate sourceDate =
-                        LocalDate.of( 2014, 1, 1 );
+            LocalDate.of( 2014, 1, 1 );
 
         Source src = SourceTargetMapper.INSTANCE.targetToSourceLocalDateMapped( target );
         assertThat( src ).isNotNull();
@@ -138,7 +140,7 @@ public class Java8TimeConversionTest {
         Target target = new Target();
         target.setLocalTime( dateTimeAsString );
         LocalTime sourceTime =
-                        LocalTime.of( 0, 0 );
+            LocalTime.of( 0, 0 );
 
         Source src = SourceTargetMapper.INSTANCE.targetToSourceLocalTimeMapped( target );
         assertThat( src ).isNotNull();
@@ -169,13 +171,14 @@ public class Java8TimeConversionTest {
         Source src = SourceTargetMapper.INSTANCE.targetToSource( target );
 
         assertThat( src.getZonedDateTime() ).isEqualTo(
-                        ZonedDateTime.of(
-                                        java.time.LocalDateTime.of(
-                                                        2014,
-                                                        1,
-                                                        1,
-                                                        0,
-                                                        0 ), ZoneId.of( "UTC" ) ) );
+            ZonedDateTime.of(
+                java.time.LocalDateTime.of(
+                    2014,
+                    1,
+                    1,
+                    0,
+                    0
+                ), ZoneId.of( "UTC" ) ) );
         assertThat( src.getLocalDateTime() ).isEqualTo( LocalDateTime.of( 2014, 1, 1, 0, 0 ) );
         assertThat( src.getLocalDate() ).isEqualTo( LocalDate.of( 2014, 1, 1 ) );
         assertThat( src.getLocalTime() ).isEqualTo( LocalTime.of( 0, 0 ) );
@@ -186,17 +189,17 @@ public class Java8TimeConversionTest {
         Source source = new Source();
         ZonedDateTime dateTime = ZonedDateTime.of( LocalDateTime.of( 2014, 1, 1, 0, 0 ), ZoneId.of( "UTC" ) );
         source.setForCalendarConversion(
-                        dateTime );
+            dateTime );
 
         Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
 
         assertThat( target.getForCalendarConversion() ).isNotNull();
         assertThat( target.getForCalendarConversion().getTimeZone() ).isEqualTo(
-                        TimeZone.getTimeZone(
-                                        "UTC" ) );
+            TimeZone.getTimeZone(
+                "UTC" ) );
         assertThat( target.getForCalendarConversion().get( Calendar.YEAR ) ).isEqualTo( dateTime.getYear() );
         assertThat( target.getForCalendarConversion().get( Calendar.MONTH ) ).isEqualTo(
-                        dateTime.getMonthValue() - 1 );
+            dateTime.getMonthValue() - 1 );
         assertThat( target.getForCalendarConversion().get( Calendar.DATE ) ).isEqualTo( dateTime.getDayOfMonth() );
         assertThat( target.getForCalendarConversion().get( Calendar.MINUTE ) ).isEqualTo( dateTime.getMinute() );
         assertThat( target.getForCalendarConversion().get( Calendar.HOUR ) ).isEqualTo( dateTime.getHour() );
@@ -212,7 +215,7 @@ public class Java8TimeConversionTest {
         Source source = new Source();
         ZonedDateTime dateTime = ZonedDateTime.of( LocalDateTime.of( 2014, 1, 1, 0, 0 ), ZoneId.of( "UTC" ) );
         source.setForDateConversionWithZonedDateTime(
-                        dateTime );
+            dateTime );
         Target target = SourceTargetMapper.INSTANCE.sourceToTargetDefaultMapping( source );
 
         assertThat( target.getForDateConversionWithZonedDateTime() ).isNotNull();
@@ -319,4 +322,124 @@ public class Java8TimeConversionTest {
 
         assertThat( source.getForSqlDateConversionWithLocalDate() ).isEqualTo( localDate );
     }
+
+    @Test
+    public void testInstantToStringMapping() {
+        Source source = new Source();
+        source.setForInstantConversionWithString( Instant.ofEpochSecond( 42L ) );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String periodString = target.getForInstantConversionWithString();
+        assertThat( periodString ).isEqualTo( "1970-01-01T00:00:42Z" );
+    }
+
+    @Test
+    public void testInstantToStringNullMapping() {
+        Source source = new Source();
+        source.setForInstantConversionWithString( null );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String periodString = target.getForInstantConversionWithString();
+        assertThat( periodString ).isNull();
+    }
+
+    @Test
+    public void testStringToInstantMapping() {
+        Target target = new Target();
+        target.setForInstantConversionWithString( "1970-01-01T00:00:00.000Z" );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Instant instant = source.getForInstantConversionWithString();
+        assertThat( instant ).isEqualTo( Instant.EPOCH );
+    }
+
+    @Test
+    public void testStringToInstantNullMapping() {
+        Target target = new Target();
+        target.setForInstantConversionWithString( null );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Instant instant = source.getForInstantConversionWithString();
+        assertThat( instant ).isNull();
+    }
+
+    @Test
+    public void testPeriodToStringMapping() {
+        Source source = new Source();
+        source.setForPeriodConversionWithString( Period.ofDays( 42 ) );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String periodString = target.getForPeriodConversionWithString();
+        assertThat( periodString ).isEqualTo( "P42D" );
+    }
+
+    @Test
+    public void testPeriodToStringNullMapping() {
+        Source source = new Source();
+        source.setForPeriodConversionWithString( null );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String periodString = target.getForPeriodConversionWithString();
+        assertThat( periodString ).isNull();
+    }
+
+    @Test
+    public void testStringToPeriodMapping() {
+        Target target = new Target();
+        target.setForPeriodConversionWithString( "P1Y2M3D" );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Period period = source.getForPeriodConversionWithString();
+        assertThat( period ).isEqualTo( Period.of( 1, 2, 3 ) );
+    }
+
+    @Test
+    public void testStringToPeriodNullMapping() {
+        Target target = new Target();
+        target.setForPeriodConversionWithString( null );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Period period = source.getForPeriodConversionWithString();
+        assertThat( period ).isNull();
+    }
+
+    @Test
+    public void testDurationToStringMapping() {
+        Source source = new Source();
+        source.setForDurationConversionWithString( Duration.ofMinutes( 42L ) );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String durationString = target.getForDurationConversionWithString();
+        assertThat( durationString ).isEqualTo( "PT42M" );
+    }
+
+    @Test
+    public void testDurationToStringNullMapping() {
+        Source source = new Source();
+        source.setForDurationConversionWithString( null );
+
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+        String durationString = target.getForDurationConversionWithString();
+        assertThat( durationString ).isNull();
+    }
+
+    @Test
+    public void testStringToDurationMapping() {
+        Target target = new Target();
+        target.setForDurationConversionWithString( "PT20.345S" );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Duration duration = source.getForDurationConversionWithString();
+        assertThat( duration ).isEqualTo( Duration.ofSeconds( 20L, 345000000L ) );
+    }
+
+    @Test
+    public void testStringToDurationNullMapping() {
+        Target target = new Target();
+        target.setForDurationConversionWithString( null );
+
+        Source source = SourceTargetMapper.INSTANCE.targetToSource( target );
+        Duration duration = source.getForDurationConversionWithString();
+        assertThat( duration ).isNull();
+    }
 }

processor/src/test/java/org/mapstruct/ap/test/conversion/java8time/Source.java

@@ -5,10 +5,12 @@
  */
 package org.mapstruct.ap.test.conversion.java8time;
 
+import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.Period;
 import java.time.ZonedDateTime;
 
 /**
@@ -36,6 +38,12 @@ public class Source {
 
     private Instant forDateConversionWithInstant;
 
+    private Instant forInstantConversionWithString;
+
+    private Period forPeriodConversionWithString;
+
+    private Duration forDurationConversionWithString;
+
     public ZonedDateTime getZonedDateTime() {
         return zonedDateTime;
     }
@@ -115,4 +123,28 @@ public class Source {
     public void setForDateConversionWithInstant(Instant forDateConversionWithInstant) {
         this.forDateConversionWithInstant = forDateConversionWithInstant;
     }
+
+    public Instant getForInstantConversionWithString() {
+        return forInstantConversionWithString;
+    }
+
+    public void setForInstantConversionWithString(Instant forInstantConversionWithString) {
+        this.forInstantConversionWithString = forInstantConversionWithString;
+    }
+
+    public Period getForPeriodConversionWithString() {
+        return forPeriodConversionWithString;
+    }
+
+    public void setForPeriodConversionWithString(Period forPeriodConversionWithString) {
+        this.forPeriodConversionWithString = forPeriodConversionWithString;
+    }
+
+    public Duration getForDurationConversionWithString() {
+        return forDurationConversionWithString;
+    }
+
+    public void setForDurationConversionWithString(Duration forDurationConversionWithString) {
+        this.forDurationConversionWithString = forDurationConversionWithString;
+    }
 }

processor/src/test/java/org/mapstruct/ap/test/conversion/java8time/Target.java

@@ -33,6 +33,12 @@ public class Target {
 
     private Date forDateConversionWithInstant;
 
+    private String forInstantConversionWithString;
+
+    private String forPeriodConversionWithString;
+
+    private String forDurationConversionWithString;
+
     public String getZonedDateTime() {
         return zonedDateTime;
     }
@@ -112,4 +118,28 @@ public class Target {
     public void setForDateConversionWithInstant(Date forDateConversionWithInstant) {
         this.forDateConversionWithInstant = forDateConversionWithInstant;
     }
+
+    public String getForInstantConversionWithString() {
+        return forInstantConversionWithString;
+    }
+
+    public void setForInstantConversionWithString(String forInstantConversionWithString) {
+        this.forInstantConversionWithString = forInstantConversionWithString;
+    }
+
+    public String getForPeriodConversionWithString() {
+        return forPeriodConversionWithString;
+    }
+
+    public void setForPeriodConversionWithString(String forPeriodConversionWithString) {
+        this.forPeriodConversionWithString = forPeriodConversionWithString;
+    }
+
+    public String getForDurationConversionWithString() {
+        return forDurationConversionWithString;
+    }
+
+    public void setForDurationConversionWithString(String forDurationConversionWithString) {
+        this.forDurationConversionWithString = forDurationConversionWithString;
+    }
 }