pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
  Copyright 2015 Google LLC

  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.
-->
<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 http://maven.apache.org/maven-v4_0_0.xsd" child.project.url.inherit.append.path="false">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.google.code.gson</groupId>
  <artifactId>gson-parent</artifactId>
  <version>2.10.2-SNAPSHOT</version>
  <packaging>pom</packaging>

  <name>Gson Parent</name>
  <description>Gson JSON library</description>
  <url>https://github.com/google/gson</url>

  <modules>
    <module>gson</module>
    <module>graal-native-image-test</module>
    <module>shrinker-test</module>
    <module>extras</module>
    <module>metrics</module>
    <module>proto</module>
  </modules>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.release>7</maven.compiler.release>
    <maven.compiler.testRelease>11</maven.compiler.testRelease>

    <!-- Make the build reproducible, see https://maven.apache.org/guides/mini/guide-reproducible-builds.html -->
    <!-- Automatically updated by Maven Release Plugin -->
    <project.build.outputTimestamp>2023-01-01T00:00:00Z</project.build.outputTimestamp>
  </properties>

  <!-- These attributes specify that the URLs should be inherited by the modules as is, to avoid constructing
    invalid URLs, see also https://maven.apache.org/ref/3.9.1/maven-model-builder/index.html#inheritance-assembly -->
  <scm child.scm.url.inherit.append.path="false" child.scm.connection.inherit.append.path="false" child.scm.developerConnection.inherit.append.path="false">
    <url>https://github.com/google/gson/</url>
    <connection>scm:git:https://github.com/google/gson.git</connection>
    <developerConnection>scm:git:git@github.com:google/gson.git</developerConnection>
    <tag>HEAD</tag>
  </scm>

  <developers>
    <developer>
      <id>google</id>
      <organization>Google</organization>
      <organizationUrl>https://www.google.com</organizationUrl>
    </developer>
  </developers>

  <issueManagement>
    <system>GitHub Issues</system>
    <url>https://github.com/google/gson/issues</url>
  </issueManagement>

  <licenses>
    <license>
      <name>Apache-2.0</name>
      <url>https://www.apache.org/licenses/LICENSE-2.0.txt</url>
    </license>
  </licenses>

  <distributionManagement>
    <repository>
      <id>sonatype-nexus-staging</id>
      <name>Nexus Release Repository</name>
      <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
    </repository>
  </distributionManagement>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
      </dependency>

      <dependency>
        <groupId>com.google.truth</groupId>
        <artifactId>truth</artifactId>
        <version>1.4.2</version>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-enforcer-plugin</artifactId>
        <version>3.4.1</version>
        <executions>
          <execution>
            <id>enforce-versions</id>
            <goals>
              <goal>enforce</goal>
            </goals>
            <configuration>
              <rules>
                <requireMavenVersion>
                  <!-- Usage of `.mvn/jvm.config` for Error Prone requires at least Maven 3.3.1 -->
                  <version>[3.3.1,)</version>
                </requireMavenVersion>

                <!-- Enforce that correct JDK version is used to avoid cryptic build errors -->
                <requireJavaVersion>
                  <!-- Other plugins of this build require at least JDK 11 -->
                  <!-- Fail fast when building with JDK > 17 because it causes build failures,
                    see https://github.com/google/gson/issues/2501 -->
                  <version>[11,18)</version>
                </requireJavaVersion>
              </rules>
            </configuration>
          </execution>
        </executions>
      </plugin>

      <!-- Spotless plugin: keeps the code formatted following the google-java-styleguide -->
      <plugin>
        <groupId>com.diffplug.spotless</groupId>
        <artifactId>spotless-maven-plugin</artifactId>
        <version>2.43.0</version>
        <executions>
          <execution>
            <goals>
              <goal>check</goal>
            </goals>
          </execution>
        </executions>
        <!-- Note: The configuration here is not specific to the `<execution>` above to allow users to run
          `mvn spotless:apply` from the command line, using the same configuration -->
        <configuration>
          <!-- Perform some basic formatting for non-Java code -->
          <formats>
            <format>
              <includes>
                <include>*.md</include>
                <include>*.xml</include>
                <include>.github/**/*.yml</include>
                <include>.gitignore</include>
              </includes>
              <!-- For Markdown files removing trailing whitespace causes issues for hard line breaks,
                which use two trailing spaces. However, the trailing spaces are difficult to notice anyway;
                prefer a trailing `\` instead of two spaces. -->
              <trimTrailingWhitespace />
              <endWithNewline />
              <indent>
                <spaces>true</spaces>
                <!-- This seems to mostly (or only?) affect the suggested fix in case code contains tabs -->
                <spacesPerTab>2</spacesPerTab>
              </indent>
            </format>
          </formats>

          <java>
            <excludes>
              <!-- Exclude classes which need Java 17 for compilation; Google Java Format internally relies on javac,
                so formatting will fail if build is executed with JDK 11 -->
              <exclude>src/test/java/com/google/gson/functional/Java17RecordTest.java</exclude>
              <exclude>src/test/java/com/google/gson/native_test/Java17RecordReflectionTest.java</exclude>
            </excludes>
            <googleJavaFormat>
              <style>GOOGLE</style>
              <reflowLongStrings>true</reflowLongStrings>
              <reorderImports>true</reorderImports>
              <formatJavadoc>true</formatJavadoc>
            </googleJavaFormat>
            <formatAnnotations />     <!-- Puts type annotations immediately before types. -->
          </java>
        </configuration>
      </plugin>

      <!-- Attaches a `.buildinfo` file which contains information for reproducing the build,
        such as OS, JDK version, ...
        Since this is a multi-module Maven project, only one aggregated file will be created for
        the last module, see the note on https://maven.apache.org/plugins/maven-artifact-plugin/usage.html#recording-buildinfo-file -->
      <!-- The other goals of this plugin are run by the GitHub workflow to verify that
        the build is reproducible (see `artifact:...` usage in the workflow) -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-artifact-plugin</artifactId>
        <version>3.5.1</version>
        <executions>
          <execution>
            <goals>
              <!-- This logs a warning about `source.scm.tag=HEAD`, but this can be ignored;
                during release Maven Release Plugin temporarily changes the `source.scm.tag`
                value to the actual Git tag, which will then not cause a warning -->
              <goal>buildinfo</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>

    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.13.0</version>
          <configuration>
            <showWarnings>true</showWarnings>
            <showDeprecation>true</showDeprecation>
            <failOnWarning>true</failOnWarning>
            <compilerArgs>
              <!-- Args related to Error Prone, see: https://errorprone.info/docs/installation#maven -->
              <arg>-XDcompilePolicy=simple</arg>
              <arg>-Xplugin:ErrorProne
                -XepExcludedPaths:.*/generated-test-sources/protobuf/.*
                -Xep:NotJavadoc:OFF <!-- Triggered by local class. -->
                <!-- Increase severity from 'suggestion' to 'warning' so that the user has to fix
                  found issues, and they are not overlooked
                  TODO: Does not work properly yet, see https://github.com/google/error-prone/issues/4206,
                        so for now have to manually set them to `:WARN` -->
                -XepAllSuggestionsAsWarnings
                <!-- Enable some experimental checks which are disabled by default
                  In case they cause issues or are unreliable turn them off by adding `:OFF`,
                  and add a comment mentioning why they were disabled -->
                -Xep:AnnotationPosition <!-- required by style guide -->
                -Xep:AssertFalse
                -Xep:ClassName <!-- required by style guide -->
                -Xep:ClassNamedLikeTypeParameter:WARN
                -Xep:ComparisonContractViolated
                -Xep:ConstantField:WARN <!-- required by style guide -->
                -Xep:DepAnn
                -Xep:DifferentNameButSame
                -Xep:EmptyIf
                -Xep:EqualsBrokenForNull
                -Xep:ForEachIterable:WARN
                -Xep:FunctionalInterfaceClash
                -Xep:InitializeInline
                -Xep:InterfaceWithOnlyStatics
                -Xep:LambdaFunctionalInterface:WARN <!-- only relevant for test code at the moment, which uses Java 11 -->
                -Xep:LongLiteralLowerCaseSuffix <!-- required by style guide -->
                -Xep:MemberName <!-- required by style guide -->
                -Xep:MissingBraces:WARN
                -Xep:MissingDefault <!-- required by style guide -->
                -Xep:MixedArrayDimensions:WARN <!-- required by style guide -->
                -Xep:MultiVariableDeclaration:WARN <!-- required by style guide -->
                -Xep:MultipleTopLevelClasses:WARN <!-- required by style guide -->
                -Xep:NonCanonicalStaticMemberImport
                -Xep:NonFinalStaticField
                -Xep:PackageLocation:WARN
                -Xep:PrimitiveArrayPassedToVarargsMethod
                -Xep:PrivateConstructorForUtilityClass:WARN
                -Xep:RemoveUnusedImports:WARN
                -Xep:StatementSwitchToExpressionSwitch:OFF <!-- disabled: requires Java 14 -->
                -Xep:StaticQualifiedUsingExpression <!-- required by style guide -->
                -Xep:SwitchDefault:WARN
                -Xep:SystemExitOutsideMain
                -Xep:SystemOut
                -Xep:TestExceptionChecker
                -Xep:ThrowSpecificExceptions:OFF <!-- disabled: Gson has no proper exception hierarchy yet, see https://github.com/google/gson/issues/2359 -->
                -Xep:TryFailRefactoring:OFF <!-- disabled: there are too many tests which violate this -->
                -Xep:TypeParameterNaming:WARN <!-- required by style guide -->
                -Xep:UnescapedEntity
                -Xep:UngroupedOverloads:WARN <!-- required by style guide -->
                -Xep:UnnecessarilyFullyQualified
                -Xep:UnnecessarilyUsedValue
                -Xep:UnnecessaryAnonymousClass:OFF <!-- disabled: requires Java 8 -->
                -Xep:UnnecessaryBoxedVariable:WARN
                -Xep:UnnecessaryDefaultInEnumSwitch
                -Xep:UnnecessaryFinal:OFF <!-- disabled: requires Java 8 -->
                -Xep:UnnecessaryStaticImport:WARN <!-- required by style guide -->
                -Xep:UnusedException
                -Xep:UrlInSee
                -Xep:UseCorrectAssertInTests
                -Xep:UseEnumSwitch:WARN
                -Xep:WildcardImport:WARN <!-- required by style guide -->
                -Xep:YodaCondition
              </arg>
              <!-- Enable all warnings, except for ones which cause issues when building with newer JDKs, see also
                https://docs.oracle.com/en/java/javase/11/tools/javac.html -->
              <compilerArg>-Xlint:all,-options</compilerArg>
            </compilerArgs>
            <annotationProcessorPaths>
              <path>
                <groupId>com.google.errorprone</groupId>
                <artifactId>error_prone_core</artifactId>
                <version>2.27.0</version>
              </path>
            </annotationProcessorPaths>
          </configuration>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-javadoc-plugin</artifactId>
          <version>3.6.3</version>
          <configuration>
            <!-- Specify newer JDK as target to allow linking to newer Java API, and to generate
              module overview in Javadoc for Gson's module descriptor -->
            <release>11</release>
            <!-- Exclude `missing` group because some tags have been omitted when they are redundant -->
            <doclint>all,-missing</doclint>
            <!-- Link against newer Java API Javadoc because most users likely
              use a newer Java version than the one used for building this project -->
            <detectJavaApiLink>false</detectJavaApiLink>
            <links>
              <link>https://docs.oracle.com/en/java/javase/11/docs/api/</link>
              <link>https://errorprone.info/api/latest/</link>
            </links>
            <!-- Disable detection of offline links between Maven modules:
              (1) Only `gson` module is published, so for other modules Javadoc links don't
              matter much at the moment; (2) The derived URL for the modules is based on
              the project URL (= Gson GitHub repo) which is incorrect because it is not
              hosting the Javadoc (3) It might fail due to https://bugs.openjdk.java.net/browse/JDK-8212233 -->
            <detectOfflineLinks>false</detectOfflineLinks>
            <!-- Only show warnings and errors -->
            <quiet>true</quiet>
            <failOnWarnings>true</failOnWarnings>
          </configuration>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>3.2.5</version>
          </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.4.1</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-install-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-source-plugin</artifactId>
          <version>3.3.1</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-gpg-plugin</artifactId>
          <version>3.2.4</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-release-plugin</artifactId>
          <version>3.0.1</version>
          <configuration>
            <autoVersionSubmodules>true</autoVersionSubmodules>
            <!-- Disable Maven Super POM release profile and instead use own one -->
            <useReleaseProfile>false</useReleaseProfile>
            <releaseProfiles>release</releaseProfiles>
            <!-- Run custom goals to replace version references, see plugin configuration below -->
            <!-- Also run `verify` to make sure tests still pass with new version number;
              also seems to be necessary because without `package`, goals fail for modules depending
              on each other; possibly same issue as https://issues.apache.org/jira/browse/MRELEASE-271 -->
            <preparationGoals>
              clean verify
              antrun:run@replace-version-placeholders
              antrun:run@replace-old-version-references
              antrun:run@git-add-changed
            </preparationGoals>
          </configuration>
        </plugin>
        <plugin>
          <artifactId>maven-antrun-plugin</artifactId>
          <version>3.1.0</version>
          <executions>
            <!-- Replaces version placeholders with the current version; this is mainly useful for
              Javadoc where this allows writing `@since $next-version$` -->
            <execution>
              <id>replace-version-placeholders</id>
              <goals>
                <goal>run</goal>
              </goals>
              <configuration>
                <target>
                  <replace token="$next-version$" value="${project.version}" encoding="${project.build.sourceEncoding}">
                    <!-- erroronmissingdir=false for gson-parent which does not have source directory -->
                    <fileset dir="${project.build.sourceDirectory}" includes="**" erroronmissingdir="false" />
                  </replace>
                </target>
              </configuration>
            </execution>
            <!-- Replaces references to the old version in the documentation -->
            <execution>
              <id>replace-old-version-references</id>
              <goals>
                <goal>run</goal>
              </goals>
              <configuration>
                <target>
                  <!-- Replace Maven and Gradle version references; uses regex lookbehind and lookahead -->
                  <replaceregexp match="(?&lt;=&lt;version&gt;).*(?=&lt;/version&gt;)|(?&lt;='com\.google\.code\.gson:gson:).*(?=')" flags="g" replace="${project.version}" encoding="${project.build.sourceEncoding}">
                    <fileset dir="${project.basedir}">
                      <include name="README.md" />
                      <include name="UserGuide.md" />
                    </fileset>
                  </replaceregexp>
                </target>
              </configuration>
              <!-- Only has to be executed for parent project; don't inherit this to modules -->
              <!-- This might be a bit hacky; execution with this ID seems to be missing for modules and Maven just executes default
                configuration which does not have any targets configured. (not sure if this behavior is guaranteed) -->
              <inherited>false</inherited>
            </execution>
            <!-- Adds changed files to the Git index; workaround because Maven Release Plugin does not support committing
              additional files yet (https://issues.apache.org/jira/browse/MRELEASE-798), and for workarounds with
              Maven SCM Plugin it is apparently necessary to know modified files in advance -->
            <!-- Maven Release Plugin then just happens to include these changed files in its Git commit;
              not sure if this behavior is guaranteed or if this relies on implementation details -->
            <execution>
              <id>git-add-changed</id>
              <goals>
                <goal>run</goal>
              </goals>
              <configuration>
                <target>
                  <exec executable="git" dir="${project.basedir}" failonerror="true">
                    <arg value="add" />
                    <!-- Don't add (unrelated) not yet tracked files -->
                    <arg value="--update" />
                    <arg value="." />
                  </exec>
                </target>
              </configuration>
            </execution>
          </executions>
        </plugin>

        <!-- Plugin for checking source and binary compatibility; used by GitHub workflow -->
        <plugin>
          <groupId>com.github.siom79.japicmp</groupId>
          <artifactId>japicmp-maven-plugin</artifactId>
          <version>0.21.1</version>
          <configuration>
            <oldVersion>
              <dependency>
                <groupId>${project.groupId}</groupId>
                <artifactId>${project.artifactId}</artifactId>
                <!-- This is set by the GitHub workflow -->
                <version>JAPICMP-OLD</version>
              </dependency>
            </oldVersion>
            <newVersion>
              <file>
                <path>${project.build.directory}/${project.build.finalName}.${project.packaging}</path>
              </file>
            </newVersion>
            <parameter>
              <breakBuildOnSourceIncompatibleModifications>true</breakBuildOnSourceIncompatibleModifications>
              <breakBuildOnBinaryIncompatibleModifications>true</breakBuildOnBinaryIncompatibleModifications>
              <excludes>
                <exclude>com.google.gson.internal</exclude>
              </excludes>
              <onlyModified>true</onlyModified>
              <skipXmlReport>true</skipXmlReport>
              <reportOnlyFilename>true</reportOnlyFilename>
            </parameter>
          </configuration>
        </plugin>

        <!-- Plugin for checking compatibility with Android API -->
        <!-- Note: For now this is not part of a normal Maven build but instead executed only by a
          GitHub workflow because the Animal Sniffer signature files use Java Serialization, so they
          could in theory contain malicious data (in case we don't fully trust the author) -->
        <plugin>
          <groupId>org.codehaus.mojo</groupId>
          <artifactId>animal-sniffer-maven-plugin</artifactId>
          <version>1.23</version>
          <executions>
            <execution>
              <id>check-android-compatibility</id>
              <goals>
                <goal>check</goal>
              </goals>
              <configuration>
                <signature>
                  <!-- Note: In case Android compatibility impedes Gson development too much in the
                    future, could consider switching to https://github.com/open-toast/gummy-bears
                    which accounts for Android desugaring and might allow usage of more Java classes -->
                  <groupId>net.sf.androidscents.signature</groupId>
                  <artifactId>android-api-level-21</artifactId>
                  <version>5.0.1_r2</version>
                </signature>
              </configuration>
            </execution>
          </executions>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>

  <profiles>
    <!-- Disable Error Prone in Java 15 -->
    <profile>
      <id>jdk15</id>
      <activation>
        <jdk>15</jdk>
      </activation>
      <build>
        <plugins>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
             <compilerArgs combine.self="override">
               <compilerArg>-Xlint:all,-options</compilerArg>
             </compilerArgs>
            </configuration>
          </plugin>
        </plugins>
      </build>
    </profile>

    <!-- Slightly adjust build to support building with JDK >= 21
      However, by default this will intentionally be blocked by the Maven Enforcer Plugin defined above
      and must be explicitly circumvented to avoid building non-release Gson artifacts by accident -->
    <profile>
      <id>jdk21+</id>
      <activation>
        <jdk>[21,)</jdk>
      </activation>
      <properties>
        <!-- JDK 21 does not support Java 7 as release, must use at least Java 8 -->
        <maven.compiler.release>8</maven.compiler.release>
      </properties>
    </profile>

    <!-- Profile defining additional plugins to be executed for release -->
    <profile>
      <id>release</id>
      <build>
        <plugins>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-source-plugin</artifactId>
            <executions>
              <execution>
                <id>attach-sources</id>
                <goals>
                  <goal>jar-no-fork</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-javadoc-plugin</artifactId>
            <executions>
              <execution>
                <id>attach-javadocs</id>
                <goals>
                  <goal>jar</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-gpg-plugin</artifactId>
            <executions>
              <execution>
                <id>sign-artifacts</id>
                <phase>verify</phase>
                <goals>
                  <goal>sign</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
        </plugins>
      </build>
    </profile>
  </profiles>
</project>