How to access a resource file in src/main/resources/ folder in Spring Boot
In this blog post we will see different ways to access resource file in src/main/resources folder in Spring Boot.
1) Using ResourceLoader
@RestController
public class WelcomeController {
@Autowired
private ResourceLoader resourceLoader;
@GetMapping("/readTextFile")
public String readTextFile() throws IOException {
Resource resource = resourceLoader.getResource("classpath:greetings.txt");
String content = resource.getContentAsString(StandardCharsets.UTF_8);
return content.formatted("sayHello");
}
}Code language: Java (java)2) Using Resource
@RestController
public class WelcomeController {
@Value("classpath:/greetings.txt")
private Resource resource;
@GetMapping("/readTextFile")
public String readTextFile() throws IOException {
String content = resource.getContentAsString(StandardCharsets.UTF_8);
return content.formatted("sayHello");
}
}Code language: Java (java)3) Using ClassPathResource
@RestController
public class WelcomeController {
@GetMapping("/readTextFile")
public String readTextFile() throws IOException {
ClassPathResource classPathResource = new ClassPathResource("greetings.txt");
String content = classPathResource.getContentAsString(StandardCharsets.UTF_8);
return content.formatted("sayHello");
}
}Code language: Java (java)4) Using ClassLoader
@RestController
public class WelcomeController {
@GetMapping("/readTextFile")
public String readTextFile() throws IOException, URISyntaxException {
InputStream stream = getClass().getClassLoader().getResourceAsStream("greetings.txt");
assert stream != null;
String content = new String(stream.readAllBytes());
return content.formatted("sayHello");
}
}Code language: Java (java) @GetMapping("/readTextFile")
public String readTextFile() throws IOException {
InputStream stream = getClass().getResourceAsStream("/greetings.txt");
assert stream != null;
String content = new String(stream.readAllBytes());
return content.formatted("sayHello");
}Code language: Java (java)Note : In above code example, the path should always start with “/”
5) Using ContextClassLoader
@RestController
public class WelcomeController {
@GetMapping("/readTextFile")
public String readTextFile() throws IOException {
InputStream stream = Thread.currentThread().getContextClassLoader().getResourceAsStream("greetings.txt");
assert stream != null;
String content = new String(stream.readAllBytes());
return content.formatted("sayHello");
}
}Code language: Java (java)Sourcecode for blog post can be downloaded from GitHub