In my Spring Boot 1.5 application I use ClassPathResource to read a static file the application JAR:
// ...
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
@Slf4j
@Service
public class MyService {
private Resource resource = new ClassPathResource("a.txt");
private List<String> myStrings;
public MyService() {
myStrings = load(resource);
}
private List<String> load(Resource resource) {
try(Stream<String> stream = Files.lines(Paths.get(resource.getURI()))) {
myStrings = stream.filter(/* my filter */)
.collect(Collectors.toList());
} catch (IOException x) {
log.error("Failed to read '{}'.", resource.getFilename());
}
}
}
but this fails with:
Caused by: java.nio.file.FileSystemNotFoundException: null
at com.sun.nio.zipfs.ZipFileSystemProvider.getFileSystem(ZipFileSystemProvider.java:171) ~[zipfs.jar:1.8.0_121]
at com.sun.nio.zipfs.ZipFileSystemProvider.getPath(ZipFileSystemProvider.java:157) ~[zipfs.jar:1.8.0_121]
at java.nio.file.Paths.get(Paths.java:143) ~[na:1.8.0_121]
at MyService.load(MyService.java:53) ~[classes!/:2.0.0-SNAPSHOT]
//...
How can I read a ClassPathResource embedded in my application JAR?
The JDK's Paths.get cannot resolve resources within JAR files so replace:
Files.lines(Paths.get(resource.getURI()))
with:
new BufferedReader(new InputStreamReader(resource.getInputStream())).lines();