升级Spring Boot3+与Java17后Spotless removeUnusedImports报错

将Spring Boot应用升级到3.1.3版本并切换到Java 17后，使用Spotless插件的removeUnusedImports功能时出现错误，该问题与已报告的同类问题情况一致。

已尝试的解决方案 #

• 按照Google Java Format的IntelliJ配置指南，向IntelliJ的VM选项添加以下参数：

-Xmx4096m
--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED

• 在Git终端中设置MAVEN_OPTS参数，尝试将上述配置添加到Maven中（原命令存在截断）：

export MAVEN_OPTS="-Xmx4096m --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.u
$ git config --global credential.helper "cache --timeout=3600"

当前使用的版本信息 #

<spotless-plugin.version>2.34.0</spotless-plugin.version>
<spotless-eclipse.version>4.18.0</spotless-eclipse.version>
<spring-boot.version>3.1.3</spring-boot.version>

Spotless Maven插件配置 #

<plugin>
    <groupId>com.diffplug.spotless</groupId>
    <artifactId>spotless-maven-plugin</artifactId>
    <version>${spotless-plugin.version}</version>
    <configuration>
        <formats>
            <format>
                <includes>
                    <include>*.java</include>
                    <include>*.md</include>
                </includes>
                <trimTrailingWhitespace/>
                <endWithNewline/>
                <indent>
                    <tabs>true</tabs>
                    <spacesPerTab>4</spacesPerTab>
                </indent>
            </format>
        </formats>
        <java>
            <removeUnusedImports/>
            <eclipse>
                <version>${spotless-eclipse.version}</version>
                <file>${project.basedir}/eclipse-formatter.xml</file>
            </eclipse>
        </java>
    </configuration>
</plugin>

具体报错信息 #

[INFO] Spotless.Format is keeping 1 files clean - 0 were changed to be clean, 1 were already clean, 0 were skipped because caching determined they were already clean
[ERROR] Step 'removeUnusedImports' found problem in 'src\test\java\com\myproject\amlar\client\DBClient.java':
null
java.lang.reflect.InvocationTargetException
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at com.diffplug.spotless.java.GoogleJavaFormatStep$State.lambda$constructRemoveUnusedFunction$4 (GoogleJavaFormatStep.java:211)
Caused by: com.google.googlejavaformat.java.FormatterException: 37:25: error: unclosed string literal
    at com.google.googlejavaformat.java.FormatterException.fromJavacDiagnostics (FormatterException.java:51)
    at com.google.googlejavaformat.java.RemoveUnusedImports.parse (RemoveUnusedImports.java:262)
    at com.google.googlejavaformat.java.RemoveUnusedImports.removeUnusedImports (RemoveUnusedImports.java:219)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at com.diffplug.spotless.java.GoogleJavaFormatStep$State.lambda$constructRemoveUnusedFunction$4 (GoogleJavaFormatStep.java:211)
    at com.diffplug.spotless.java.GoogleJavaFormatStep$State.lambda$createRemoveUnusedImportsOnly$2 (GoogleJavaFormatStep.java:188)
    at com.diffplug.spotless.FormatterFunc.apply (FormatterFunc.java:32)
    at com.diffplug.spotless.FormatterStepImpl$Standard.format (FormatterStepImpl.java:82)
    at com.diffplug.spotless.FormatterStep$Strict.format (FormatterStep.java:88)
    at com.diffplug.spotless.Formatter.compute (Formatter.java:246)
    at com.diffplug.spotless.PaddedCell.calculateDirtyState (PaddedCell.java:203)
    at com.diffplug.spotless.PaddedCell.calculateDirtyState (PaddedCell.java:190)
    at com.diffplug.spotless.maven.SpotlessApplyMojo.process (SpotlessApplyMojo.java:48)
    at com.diffplug.spotless.maven.AbstractSpotlessMojo.execute (AbstractSpotlessMojo.java:225)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.439 s
[INFO] Finished at: 2023-09-18T12:43:17+01:00

解决方案 #

1. 修复目标文件语法错误
   报错明确指出DBClient.java第37行第25位存在未闭合的字符串字面量，这是Spotless解析失败的直接原因。先手动修复该文件的语法问题，再重新运行插件。

2. 升级Spotless插件版本
   当前使用的2.34.0版本对Java 17兼容性支持不足，建议升级到最新稳定版（如3.x系列），新版本已修复大量Java 17相关的解析兼容问题。

3. 修正MAVEN_OPTS配置
   原命令存在截断，完整配置应为：

   export MAVEN_OPTS="-Xmx4096m --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED"
   

   配置完成后重启终端，再执行Maven命令。

4. 切换到Eclipse的移除未使用导入功能
   将removeUnusedImports配置移到Eclipse节点下，使用Eclipse的解析逻辑替代Google Java Format的实现，避免兼容问题：

   <java>
       <eclipse>
           <version>${spotless-eclipse.version}</version>
           <file>${project.basedir}/eclipse-formatter.xml</file>
           <removeUnusedImports/>
       </eclipse>
   </java>
   

内容的提问来源于stack exchange，提问作者Francislainy Campos