How to read a static file on Heroku deployment on Spring Boot

Question

How can I solve this situation? I have a static JSON file on my src/main/resources and when I run the code, I use this JSON to create some data, but when I try to deploy on heroku I get this error, probably because they couldn't find the FUNDOS.json file.

Does anyone have an idea on how to solve that?

Code

String FUNDOS_JSON = "src/main/resources/data/FUNDOS.json";
Path filePath = Path.of(FUNDOS_JSON).toAbsolutePath();
String jsonString = Files.readString(filePath);
            
JSONArray json = new JSONArray(jsonString); 

Error

remote:        [ERROR] COMPILATION ERROR :
remote:        [INFO] -------------------------------------------------------------
remote:        [ERROR] /tmp/build_835ef365/src/main/java/br/anbima/mvc/service/AnbimaServiceImpl.java:[36,37] cannot find symbol
remote:          symbol:   method of(java.lang.String)
remote:          location: interface java.nio.file.Path
remote:        [ERROR] /tmp/build_835ef365/src/main/java/br/anbima/mvc/service/AnbimaServiceImpl.java:[37,42] cannot find symbol
remote:          symbol:   method readString(java.nio.file.Path)
remote:          location: class java.nio.file.Files
remote:        [INFO] 2 errors

Answer 1

For assets inside src/main/resources use getResourceAsStream or getResource.

Suppose your code is in a file named Foo.java,

InputStream fundosStream = Foo.class.getResourceAsStream("/data/FUNDOS.json");
String fundosContent = "";
try(BufferedReader br = new BufferedReader(new InputStreamReader(fundosStream)) {
     String line = br.readLine();
     while(line != null) {
         fundosContent = line + "\n";
         line = br.readLine();
     }
} catch(IOException ioe) {
     ioe.printStackTrace();
}
JSONArray jsonArray = new JSONArray(fundosContent);