Allow build.time to be disabled so BuildInfoMojo's output is repeatable

See gh-17390

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-custom-build-time/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>build-info-custom-build-time</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<name>Generate build info with custom build time</name>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<configuration>
+							<time>2019-07-08T08:00:00Z</time>
+						</configuration>
+						<goals>
+							<goal>build-info</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>jakarta.servlet</groupId>
+			<artifactId>jakarta.servlet-api</artifactId>
+			<version>@jakarta-servlet.version@</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-custom-build-time/src/main/java/org/test/SampleApplication.java

+/*
+ * Copyright 2012-2019 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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-custom-build-time/verify.groovy

+import org.springframework.boot.maven.Verify
+
+import static org.junit.Assert.assertEquals
+
+def file = new File(basedir, "target/classes/META-INF/build-info.properties")
+println file.getAbsolutePath()
+Properties properties = Verify.verifyBuildInfo(file,
+		'org.springframework.boot.maven.it', 'build-info-custom-build-time',
+		'Generate build info with custom build time', '0.0.1.BUILD-SNAPSHOT')
+assertEquals(properties.get('build.time'), '2019-07-08T08:00:00Z')

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-disable-build-time/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>build-info-disable-build-time</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<name>Generate build info with disabled build time</name>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<configuration>
+							<time>off</time>
+						</configuration>
+						<goals>
+							<goal>build-info</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>jakarta.servlet</groupId>
+			<artifactId>jakarta.servlet-api</artifactId>
+			<version>@jakarta-servlet.version@</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-disable-build-time/src/main/java/org/test/SampleApplication.java

+/*
+ * Copyright 2012-2019 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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/build-info-disable-build-time/verify.groovy

+import org.springframework.boot.maven.Verify
+
+import static org.junit.Assert.assertFalse
+
+def file = new File(basedir, "target/classes/META-INF/build-info.properties")
+println file.getAbsolutePath()
+Properties properties = Verify.verifyBuildInfo(file,
+		'org.springframework.boot.maven.it', 'build-info-disable-build-time',
+		'Generate build info with disabled build time', '0.0.1.BUILD-SNAPSHOT')
+assertFalse 'build time must not be present', properties.containsKey('build.time')

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

@@ -59,6 +59,15 @@ public class BuildInfoMojo extends AbstractMojo {
 	@Parameter(defaultValue = "${project.build.outputDirectory}/META-INF/build-info.properties")
 	private File outputFile;
 
+	/**
+	 * Sets the value used for the {@code build.time} property. Defaults to
+	 * {@link Instant#now} when the {@code mojo} instance was created. To disable
+	 * {@code build.time} property, {@code 'off'} value should be used.
+	 * @since 2.2.0
+	 */
+	@Parameter
+	private String time = Instant.now().toString();
+
 	/**
 	 * Additional properties to store in the build-info.properties. Each entry is prefixed
 	 * by {@code build.} in the generated build-info.properties.
@@ -71,7 +80,7 @@ public class BuildInfoMojo extends AbstractMojo {
 		try {
 			new BuildPropertiesWriter(this.outputFile).writeBuildProperties(new ProjectDetails(
 					this.project.getGroupId(), this.project.getArtifactId(), this.project.getVersion(),
-					this.project.getName(), Instant.now(), this.additionalProperties));
+					this.project.getName(), getBuildTime(), this.additionalProperties));
 			this.buildContext.refresh(this.outputFile);
 		}
 		catch (NullAdditionalPropertyValueException ex) {
@@ -82,4 +91,8 @@ public class BuildInfoMojo extends AbstractMojo {
 		}
 	}
 
+	private Instant getBuildTime() {
+		return "off".equals(this.time) ? null : Instant.parse(this.time);
+	}
+
 }