如何在Spring Boot Web应用程序中读取特定项目的元/清单。

Question

我正在开发Spring Boot MVC应用程序。要求是读取清单。mf文件以获取这个春季启动应用程序的构建编号和应用程序版本编号等。

为此，我为清单类编写了以下BEAN定义，以便可以在控制器类中自动化它。

@Configuration
public class AppConfig{
    
    @Bean("manifest")
    public java.util.jar.Manifest getManifest()
    {
        // get the full name of the application manifest file
        String appManifestFileName = this.getClass().getProtectionDomain().getCodeSource().getLocation().toString() + JarFile.MANIFEST_NAME;
        Enumeration resEnum;
        try
        {
            // get a list of all manifest files found in the jars loaded by the app
            resEnum = Thread.currentThread().getContextClassLoader().getResources(JarFile.MANIFEST_NAME);
            while (resEnum.hasMoreElements())
            {
                try
                {
                    URL url = (URL) resEnum.nextElement();
                    System.out.println("Resource url=" + url.toString());
                    // is the app manifest file?
                    if (url.toString().equals(appManifestFileName))
                    {
                        // open the manifest
                        InputStream is = url.openStream();
                        if (is != null)
                        {
                            // read the manifest and return it to the application
                            Manifest manifest = new Manifest(is);
                            return manifest;
                        }
                    }
                }
                catch (Exception e)
                {
                    // Silently ignore wrong manifests on classpath?
                }
            }
        }
        catch (IOException e1)
        {
            // Silently ignore wrong manifests on classpath?
        }
        return null;
    }
}

以上代码取自在这里。但这无济于事。它总是给我无效的对象。

AppController.java

@RestController
public class AppController
{    
    @Autowired
    private Environment env;
    
    @Autowired
    @Qualifier("manifest")
    private Manifest manifest;
    
    @GetMapping("/get-app-details")
    public String getAppDetails()
    {
        Attributes mainAttributes = manifest.getMainAttributes();
        String buildNum = mainAttributes.getValue("Build-Number");
        buildNum = buildNum.substring(buildNum.lastIndexOf('_') + 1);
        String AppVersion = env.getProperty("App.Version") + "." + buildNum;
        return "Build Number - " + buildNum + ", AppVersion - " + AppVersion;
    }
}

附加信息 - 我正在使用Gradle将此应用程序构建为战争文件，并将其部署到外部Tomcat版本9中。