InputStream is null when trying to read a resource file

Question

I have a JSON file in /src/main/resources which I'm trying to read in the following way:

private List<String> readContextFromFile(String file) {

        List<String> context = new ArrayList<>();
        try {
            InputStream in = getClass().getClassLoader().getResourceAsStream(file);
            Map<String, ArrayList> input = objectMapper.readValue(in, HashMap.class);

            context = input.get("@context");
        } catch (IOException e) {
            LOGGER.error("Error reading value {}", e.getMessage());
        }
        return context;
    }

However, InputStream is null.

This is the file path that I pass: /resources/context.json

What am I doing wrong?

The `src` directory isn't there at runtime. Have a look at where the resource actually is in your JAR or WAR file, and use that path. — user207421, Jul 19 '19 at 07:35

score 1 · Answer 1 · answered Jul 19 '19 at 07:31

1

1) /src/main/resources represents the source code, not the runtime code.
Compiled classes and processed resources ends in the target/classes folder not in the src folder.

2) About :

This is the file path that I pass: /resources/context.json

Why do you pass the resources token ? It is a Maven/Gradle directory that you will not retrieve at runtime. Only which is contained inside will be available at runtime.
What you want to pass is /context.json.

answered Jul 19 '19 at 07:31

davidxxx

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when I pass /context.json, InputStream again is null. – locus Jul 19 '19 at 07:34
Recompile your code (`mvn compile`) and check that `target/classes` contains the `context.json` file. Retry. – davidxxx Jul 19 '19 at 07:36
@ davidxxx this works. Thank you! – locus Jul 19 '19 at 07:55

InputStream is null when trying to read a resource file

1 Answers1