SpringBoot Injection on Path misinterprets absolute paths

Starting from spring-boot 2.4.4 and including spring-boot-starter-web, injection on Path objects misinterprets absolute paths which are transformed into relative paths.

For exemple with this pom file :

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.4</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>
</project>

And This Component :

@Component
public class PathInjectionIssue {
  @Value("${myconfigfile}")
  private Path configAsPath; // here is the issue

  @Value("${myconfigfile}")
  private File configAsFile; /// this one is OK

  @Value("${myconfigfile}")
  private String configFileAsString; // this one is OK this is just a string

  @PostConstruct
  public void check() {
    if (configAsPath.getNameCount() > 1) {
      throw new RuntimeException("This absolute file path [" + configAsPath.toAbsolutePath() + "] is not correct. Expected : " + configFileAsString);
    }
  }
}

This application.properties file :

myconfigfile=/conf.json

The output is :

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pathInjectionIssue': Invocation of init method failed; nested exception is java.lang.RuntimeException: This absolute file path [C:\Users\shelbert\AppData\Local\Temp\tomcat-docbase.8080.9485259209731591160\conf.json] is not correct. Expected : /conf.json

[...]

There is no issue with spring-boot 2.4.3 nor without the spring-boot-starter-web dependency

Comment From: radarsh

Came to say that I am experiencing the same. In my case, I have a Path property defined inside a @ConfigurationProperties bean and we set it using command line using the below syntax:

--<property-name>=/var/folders/t9/ddcqvwls0vb0jz04zjk_ws_80000gq/T/14198791533976608309

But by the time the application reads it, it would have already converted it by prefixing with tomcat-docbase directory to be

/private/var/folders/t9/ddcqvwls0vb0jz04zjk_ws_80000gq/T/tomcat-docbase.8080.14679614108707425001/var/folders/t9/ddcqvwls0vb0jz04zjk_ws_80000gq/T/14198791533976608309

Comment From: wilkinsona

Thanks for the report. This is a duplicate of #25881 and spring-projects/spring-framework#26702.