Classpath resource not found when running as jar

If you're using Spring framework then reading ClassPathResource into a String is pretty simple using Spring framework's FileCopyUtils:

String data = ""; ClassPathResource cpr = new ClassPathResource("static/file.txt"); try { byte[] bdata = FileCopyUtils.copyToByteArray(cpr.getInputStream()); data = new String(bdata, StandardCharsets.UTF_8); } catch (IOException e) { LOG.warn("IOException", e); } 

If you want to use a file:

ClassPathResource classPathResource = new ClassPathResource("static/something.txt"); InputStream inputStream = classPathResource.getInputStream(); File somethingFile = File.createTempFile("test", ".txt"); try { FileUtils.copyInputStreamToFile(inputStream, somethingFile); } finally { IOUtils.closeQuietly(inputStream); } 

When spring boot project running as a jar and need read some file in classpath, I implement it by below code

Resource resource = new ClassPathResource("data.sql"); BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream())); reader.lines().forEach(System.out::println); 

To get list of data from a src/main/resources/data folder: first of all mention your folder location in properties file as resourceLoader.file.location=data.

Then inside class declare your location:

@Value("${resourceLoader.file.location}") @Setter private String location; private final ResourceLoader resourceLoader; public void readallfilesfromresources() { Resource[] resources; try { resources = ResourcePatternUtils.getResourcePatternResolver(resourceLoader).getResources("classpath:" + location + "/*.json"); for (int i = 0; i < resources.length; i++) { try { InputStream is = resources[i].getInputStream(); byte[] encoded = IOUtils.toByteArray(is); String content = new String(encoded, Charset.forName("UTF-8")); } } } catch (IOException e) { throw new UncheckedIOException(e); } } 

I've created a ClassPathResourceReader class in a Java 8 way to make easy read files from classpath

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.stream.Collectors; import org.springframework.core.io.ClassPathResource; public final class ClassPathResourceReader { private final String path; private String content; public ClassPathResourceReader(String path) { this.path = path; } public String getContent() { if (content == null) { try { ClassPathResource resource = new ClassPathResource(path); BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream())); content = reader.lines().collect(Collectors.joining("\n")); reader.close(); } catch (IOException ex) { throw new RuntimeException(ex); } } return content; } } 

Utilization:

String content = new ClassPathResourceReader("data.sql").getContent(); 

My solution to read the Stream to String more efficiently (using StreamUtils) instead of trying to create a temp file and read text.

 @Bean public String readFromResource(final @Value("classpath:data/message.txt") Resource messageFile) throws IOException { return StreamUtils.copyToString(messageFile.getInputStream(), StandardCharsets.UTF_8); } 

Another important thing I noticed is that when running the application it ignores capitals in file/folders in the resources folder where it doesn't ignore it while running as a jar. Therefore, in case your file is in the resources folder under Testfolder/messages.txt

@Autowired ApplicationContext appContext; // this will work when running the application, but will fail when running as jar appContext.getResource("classpath:testfolder/message.txt"); 

Therefore, don't use capitals in your resources or also add those capitals in your constructor of ClassPathResource:

appContext.getResource("classpath:Testfolder/message.txt"); 

I encountered this limitation too and created this library to overcome the issue: spring-boot-jar-resources It basically allows you to register a custom ResourceLoader with Spring Boot that extracts the classpath resources from the JAR as needed, transparently.

Jersey needs to be unpacked jars.

<build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <requiresUnpack> <dependency> <groupId>com.myapp</groupId> <artifactId>rest-api</artifactId> </dependency> </requiresUnpack> </configuration> </plugin> </plugins> </build> 

This works on a dockerized springboot JAR.

InputStream is = new ClassPathResource("randomlists/names.txt").getInputStream(); Scanner s = new Scanner(is); ArrayList<String> names = new ArrayList<>(); while (s.hasNext()){ names.add(s.next()); } s.close(); 

Scanner have constructor with inputStream.

This is my way to read statics text resource files whit Springboot.

In the most voted answer, mentioned Interface Resource which extends Interface InputStreamSource, so I can replace getFile() with getInputStream() for Resource object.

example(using getFile()):

 @GetMapping(value = "/excel-download") public void downloadExcel(HttpServletResponse httpServletResponse) throws IOException { ServletOutputStream servletOutputStream = httpServletResponse.getOutputStream(); //resourceLoader is Dependency injection from org.springframework.core.io.ResourceLoader, can be injected from @Autowired Resource resource = resourceLoader.getResource("classpath:test.xlsx" ); File file = resource.getFile();//throws FileNotFoundException in jar execution ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(Files.readAllBytes(Paths.get(file.getAbsolutePath()))); httpServletResponse.setContentType("application/octet-stream"); String attachment = MessageFormat.format( "attachment; filename=\"{0}\"", URLEncoder.encode("test.xlsx", StandardCharsets.UTF_8.toString()) ); httpServletResponse.addHeader("Content-Disposition", attachment); IOUtils.copy(byteArrayInputStream, servletOutputStream); servletOutputStream.flush(); servletOutputStream.close(); } 

example(using getInputStream()):

 @GetMapping(value = "/excel-download") public void downloadExcel(HttpServletResponse httpServletResponse) throws IOException { ServletOutputStream servletOutputStream = httpServletResponse.getOutputStream(); //resourceLoader is Dependency injection from org.springframework.core.io.ResourceLoader, can be injected from @Autowired Resource resource = resourceLoader.getResource("classpath:test.xlsx"); InputStream inputStream = resource.getInputStream();//works in jar execution! httpServletResponse.setContentType("application/octet-stream"); String attachment = MessageFormat.format( "attachment; filename=\"{0}\"", URLEncoder.encode("test.xlsx", StandardCharsets.UTF_8.toString()) ); httpServletResponse.addHeader("Content-Disposition", attachment); IOUtils.copy(inputStream, servletOutputStream); servletOutputStream.flush(); servletOutputStream.close(); } 

The situation is, if running the project directly in any IDE or editor like IntelliJ, my both examples work but when using package manager command like mvn package, which gets a jar file containing all the dependencies we need, and we execute it with the command:

java -jar <yourJarFileName>.jar 

You will find that only the 2nd example works.

This works in Spring Boot 2.7.17.

in spring boot : 1) if your file is ouside jar you can use : @Autowired private ResourceLoader resourceLoader; **.resource(resourceLoader.getResource("file:/path_to_your_file"))** 2) if your file is inside resources of jar you can `enter code here`use : **.resource(new ClassPathResource("file_name"))** 

Based on Andy's answer I used the following to get an input streams of all YAMLs under a directory and sub-directories in resources (Note that the path passed doesn't begin with /):

private static Stream<InputStream> getInputStreamsFromClasspath( String path, PathMatchingResourcePatternResolver resolver ) { try { return Arrays.stream(resolver.getResources("/" + path + "/**/*.yaml")) .filter(Resource::exists) .map(resource -> { try { return resource.getInputStream(); } catch (IOException e) { return null; } }) .filter(Objects::nonNull); } catch (IOException e) { logger.error("Failed to get definitions from directory {}", path, e); return Stream.of(); } } 

I was facing same error

InputStream inputStream = new ClassPathResource("filename.ext").inputStream();

this should solve FileNotFoundException while running

this worked for me in a static context:

 InputStream inputStream = ClassName.class.getClassLoader().getResourceAsStream("folderName/fileName.xml"); Reader reader = new InputStreamReader(inputStream); String xml = CharStreams.toString(reader); 

I had faced same issue while running with java -jar <file_name.jar. When I run it in STS it was working fine. The below line helped me to resolve the issue

String templateFilePath = "/templates/Itemized_Report_2021_V1.xlsx"; InputStream resourceFile = getClass().getResourceAsStream(templateFilePath); 

excel report file template path ./templates/Itemized_Report_2021_V1.xlsx java.io.FileNotFoundException: D:\STS%20WORKSPACE\app\target\classes\templates\Itemized_Report_2021_V1.xlsx (The system cannot find the path specified)

Solution:

@Override public void exportExcelReport(HttpServletResponse response, List<Context> contexts) throws IOException, URISyntaxException { String templateFilePath = "/templates/Itemized_Report_2021_V1.xlsx"; InputStream resourceFile = **getClass().getResourceAsStream(templateFilePath)**; if (resourceFile == null) { throw new IllegalArgumentException("Template file not found!. " + templateFilePath); } else { ServletOutputStream outputStream = null; try { log.info("Combined report with Competency excel report file template path {}", templateFilePath); this.workbook = new XSSFWorkbook(resourceFile); prepareCompetencyReport(contexts); prepareItemizedReport(contexts); // Return as octet-stream format in the rest response outputStream = response.getOutputStream(); workbook.write(outputStream); } catch (FileNotFoundException e) { e.printStackTrace(); } finally { workbook.close(); if (outputStream != null) outputStream.close(); } } }