把项目升级到Spring boot 2.5.5，在编译原理的项目时报错:
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ myproject ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 3 resources
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.409 s
[INFO] Finished at: 2021-09-25T06:23:36+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources) on project myproject : Input length = 1 -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
原因定位
原因是我们的*.properties文件使用了非UTF-8字符：
mail.fromPerson=�뾭�ʼ�
spring-boot-starter-parent配置的maven-resources-plugin，Spring Boot 默认使用 UTF-8，如前面的提示：
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
这是maven-resources-plugin:3.2.0的一个bug，在maven-resources-plugin:3.2.0之前的插件是能够兼容非UTF-8字符。spring boot 2.4升级到maven-resources-plugin:3.2.0，就出现了这个问题。
解决方法
方法一：把非UTF-8的字符改为UTF-8字符，或者删掉
方法二：在pom文件里降低maven-resources-plugin版本为3.1.0（推荐）
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>3.1.0</version>
</plugin>
方法三：排除对含有非UTF-8的资源，包含properties文件过滤
在pom文件添加插件配置：
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>3.2.0</version>
<!-- 在此添加被排除过滤的文件 -->
<configuration>
<nonFilteredFileExtensions>
<nonFilteredFileExtension>properties</nonFilteredFileExtension>
</nonFilteredFileExtensions>
</configuration>
</plugin>
参考：