Polish "Use the Maven Archiver implementation for parsing outputTimestamp"

See gh-37438

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/MavenBuildOutputTimestamp.java

@@ -16,91 +16,97 @@
 
 package org.springframework.boot.maven;
 
+import java.nio.file.attribute.FileTime;
 import java.time.Instant;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeParseException;
 import java.time.temporal.ChronoUnit;
-import java.util.Optional;
 
-public final class MavenBuildOutputTimestamp {
+import org.springframework.util.StringUtils;
 
-	private MavenBuildOutputTimestamp() {
-		// Utility class
-	}
-
-	// This implementation was copied from the maven-archiver
-	// https://github.com/apache/maven-archiver/blob/cc2f6a219f6563f450b0c00e8ccd651520b67406/src/main/java/org/apache/maven/archiver/MavenArchiver.java#L768
+/**
+ * Parse output timestamp configured for Reproducible Builds' archive entries.
+ * <p>
+ * Either as {@link java.time.format.DateTimeFormatter#ISO_OFFSET_DATE_TIME} or as a
+ * number representing seconds since the epoch (like <a href=
+ * "https://reproducible-builds.org/docs/source-date-epoch/">SOURCE_DATE_EPOCH</a>).
+ * Implementation inspired by <a href=
+ * "https://github.com/apache/maven-archiver/blob/cc2f6a219f6563f450b0c00e8ccd651520b67406/src/main/java/org/apache/maven/archiver/MavenArchiver.java#L768">MavenArchiver</a>.
+ *
+ * @author Niels Basjes
+ * @author Moritz Halbritter
+ */
+class MavenBuildOutputTimestamp {
 
 	private static final Instant DATE_MIN = Instant.parse("1980-01-01T00:00:02Z");
 
 	private static final Instant DATE_MAX = Instant.parse("2099-12-31T23:59:59Z");
 
+	private final String timestamp;
+
+	/**
+	 * Creates a new {@link MavenBuildOutputTimestamp}.
+	 * @param timestamp timestamp or {@code null}
+	 */
+	MavenBuildOutputTimestamp(String timestamp) {
+		this.timestamp = timestamp;
+	}
+
 	/**
-	 * Parse output timestamp configured for Reproducible Builds' archive entries.
-	 *
-	 * <p>
-	 * Either as {@link java.time.format.DateTimeFormatter#ISO_OFFSET_DATE_TIME} or as a
-	 * number representing seconds since the epoch (like <a href=
-	 * "https://reproducible-builds.org/docs/source-date-epoch/">SOURCE_DATE_EPOCH</a>).
-	 * @param outputTimestamp the value of {@code ${project.build.outputTimestamp}}
-	 * (maybe {@code null})
-	 * @return the parsed timestamp as an {@code Optional<Instant>}, {@code empty} if
-	 * input is {@code null} or input contains only 1 character (not a number)
+	 * Returns the parsed timestamp as an {@code FileTime}.
+	 * @return the parsed timestamp as an {@code FileTime}, or {@code null}
 	 * @throws IllegalArgumentException if the outputTimestamp is neither ISO 8601 nor an
 	 * integer, or it's not within the valid range 1980-01-01T00:00:02Z to
 	 * 2099-12-31T23:59:59Z
 	 */
-	public static Optional<Instant> parseBuildOutputTimestamp(String outputTimestamp) {
-		// Fail-fast on nulls
-		if (outputTimestamp == null) {
-			return Optional.empty();
+	FileTime toFileTime() {
+		Instant instant = toInstant();
+		if (instant == null) {
+			return null;
 		}
+		return FileTime.from(instant);
+	}
 
-		// Number representing seconds since the epoch
-		if (isNumeric(outputTimestamp)) {
-			return Optional.of(Instant.ofEpochSecond(Long.parseLong(outputTimestamp)));
+	/**
+	 * Returns the parsed timestamp as an {@code Instant}.
+	 * @return the parsed timestamp as an {@code Instant}, or {@code null}
+	 * @throws IllegalArgumentException if the outputTimestamp is neither ISO 8601 nor an
+	 * integer, or it's not within the valid range 1980-01-01T00:00:02Z to
+	 * 2099-12-31T23:59:59Z
+	 */
+	Instant toInstant() {
+		if (!StringUtils.hasLength(this.timestamp)) {
+			return null;
 		}
-
-		// no timestamp configured (1 character configuration is useful to override a full
-		// value during pom
-		// inheritance)
-		if (outputTimestamp.length() < 2) {
-			return Optional.empty();
+		if (isNumeric(this.timestamp)) {
+			return Instant.ofEpochSecond(Long.parseLong(this.timestamp));
+		}
+		if (this.timestamp.length() < 2) {
+			return null;
 		}
-
 		try {
-			// Parse the date in UTC such as '2011-12-03T10:15:30Z' or with an offset
-			// '2019-10-05T20:37:42+06:00'.
-			final Instant date = OffsetDateTime.parse(outputTimestamp)
+			Instant instant = OffsetDateTime.parse(this.timestamp)
 				.withOffsetSameInstant(ZoneOffset.UTC)
 				.truncatedTo(ChronoUnit.SECONDS)
 				.toInstant();
-
-			if (date.isBefore(DATE_MIN) || date.isAfter(DATE_MAX)) {
-				throw new IllegalArgumentException(
-						"'" + date + "' is not within the valid range " + DATE_MIN + " to " + DATE_MAX);
+			if (instant.isBefore(DATE_MIN) || instant.isAfter(DATE_MAX)) {
+				throw new IllegalArgumentException(String
+					.format(String.format("'%s' is not within the valid range %s to %s", instant, DATE_MIN, DATE_MAX)));
 			}
-			return Optional.of(date);
+			return instant;
 		}
 		catch (DateTimeParseException pe) {
-			throw new IllegalArgumentException("Invalid project.build.outputTimestamp value '" + outputTimestamp + "'",
-					pe);
+			throw new IllegalArgumentException(String.format("Can't parse '%s' to instant", this.timestamp));
 		}
 	}
 
 	private static boolean isNumeric(String str) {
-
-		if (str.isEmpty()) {
-			return false;
-		}
-
 		for (char c : str.toCharArray()) {
 			if (!Character.isDigit(c)) {
 				return false;
 			}
 		}
-
 		return true;
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RepackageMojo.java

@@ -21,7 +21,6 @@ import java.io.IOException;
 import java.nio.file.attribute.FileTime;
 import java.util.List;
 import java.util.Properties;
-import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
 import org.apache.maven.artifact.Artifact;
@@ -220,10 +219,13 @@ public class RepackageMojo extends AbstractPackagerMojo {
 		updateArtifact(source, target, repackager.getBackupFile());
 	}
 
-	private FileTime parseOutputTimestamp() {
-		return MavenBuildOutputTimestamp.parseBuildOutputTimestamp(this.outputTimestamp)
-			.map(instant -> FileTime.from(instant.getEpochSecond(), TimeUnit.SECONDS))
-			.orElse(null);
+	private FileTime parseOutputTimestamp() throws MojoExecutionException {
+		try {
+			return new MavenBuildOutputTimestamp(this.outputTimestamp).toFileTime();
+		}
+		catch (IllegalArgumentException ex) {
+			throw new MojoExecutionException("Invalid value for parameter 'outputTimestamp'", ex);
+		}
 	}
 
 	private Repackager getRepackager(File source) {

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/MavenBuildOutputTimestampTests.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.boot.maven;
+
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
+/**
+ * Tests for {@link MavenBuildOutputTimestamp}.
+ *
+ * @author Moritz Halbritter
+ */
+class MavenBuildOutputTimestampTests {
+
+	@Test
+	void shouldParseNull() {
+		assertThat(parse(null)).isNull();
+	}
+
+	@Test
+	void shouldParseSingleDigit() {
+		assertThat(parse("0")).isEqualTo(Instant.parse("1970-01-01T00:00:00Z"));
+	}
+
+	@Test
+	void shouldNotParseSingleCharacter() {
+		assertThat(parse("a")).isNull();
+	}
+
+	@Test
+	void shouldParseIso8601() {
+		assertThat(parse("2011-12-03T10:15:30Z")).isEqualTo(Instant.parse("2011-12-03T10:15:30Z"));
+	}
+
+	@Test
+	void shouldParseIso8601WithMilliseconds() {
+		assertThat(parse("2011-12-03T10:15:30.12345Z")).isEqualTo(Instant.parse("2011-12-03T10:15:30Z"));
+	}
+
+	@Test
+	void shouldFailIfIso8601BeforeMin() {
+		assertThatIllegalArgumentException().isThrownBy(() -> parse("1970-01-01T00:00:00Z"))
+			.withMessage(
+					"'1970-01-01T00:00:00Z' is not within the valid range 1980-01-01T00:00:02Z to 2099-12-31T23:59:59Z");
+	}
+
+	@Test
+	void shouldFailIfIso8601AfterMax() {
+		assertThatIllegalArgumentException().isThrownBy(() -> parse("2100-01-01T00:00:00Z"))
+			.withMessage(
+					"'2100-01-01T00:00:00Z' is not within the valid range 1980-01-01T00:00:02Z to 2099-12-31T23:59:59Z");
+	}
+
+	@Test
+	void shouldFailIfNotIso8601() {
+		assertThatIllegalArgumentException().isThrownBy(() -> parse("dummy"))
+			.withMessage("Can't parse 'dummy' to instant");
+	}
+
+	@Test
+	void shouldParseIso8601WithOffset() {
+		assertThat(parse("2019-10-05T20:37:42+06:00")).isEqualTo(Instant.parse("2019-10-05T14:37:42Z"));
+	}
+
+	@Test
+	void shouldParseToFileTime() {
+		assertThat(parseFileTime(null)).isEqualTo(null);
+		assertThat(parseFileTime("0")).isEqualTo(FileTime.fromMillis(0));
+		assertThat(parseFileTime("2019-10-05T14:37:42Z")).isEqualTo(FileTime.fromMillis(1570286262000L));
+	}
+
+	private static Instant parse(String timestamp) {
+		return new MavenBuildOutputTimestamp(timestamp).toInstant();
+	}
+
+	private static FileTime parseFileTime(String timestamp) {
+		return new MavenBuildOutputTimestamp(timestamp).toFileTime();
+	}
+
+}