CODEWITHSUNDEEP
javaspring
pablo lamberti
pablo lamberti

Reputation: 41

Spring - Merge multiple properties from a single file into List<String>

Is it possible to merge multiple configuration properties into a single List of Strings?

Lets say I want to configure supported extensions, like this:

application.extension.pdf=pdf
application.extension.txt=txt
application.extension.docx=docx

And at runtime, it loads like this:

List<String> extensions = {"pdf","txt","docx"}

And then I can check if the list contains some extension. A Set could work too.

Upvotes: 1

Views: 1452

Answers (2)

flomo83
flomo83

Reputation: 205

You can use a bean which does the load for you and fills a map with the properties.

PropertyFile:

application.extensions.map.pdf=pdf
application.extensions.map.txt=txt
application.extensions.map.docx=docx

Bean:

@Component
@ConfigurationProperties("application.extensions")
public class ExtensionMapper {
    private Map<String, String> map = new LinkedHashMap<>();
}

This may be usefull in mapping context, where you need key and value.

(Be aware of the updated property path)

Upvotes: 1

deHaar
deHaar

Reputation: 18568

Let's assume you have a file called supported_extensions.props in a folder of your choice having the content you posted. Then you can read the lines of the file, split them by "=" and take the last part of the resulting array, which is the extension itself. Try these lines of code:

public static void main(String[] args) {

    String filePathString = "Y:\\our\\folder\\supported_extensions.props";
    Path filePath = Paths.get(filePathString);
    List<String> extensionProperties = new ArrayList<>();

    try {
        extensionProperties = Files.readAllLines(filePath);
    } catch (IOException e) {
        e.printStackTrace();
    }

    List<String> extensions = new ArrayList<>();

    extensionProperties.forEach(extensionProperty -> {
        String extension = extensionProperty.split("=")[1];
        extensions.add(extension);
    });

    extensions.forEach(extension -> {
        System.out.println(extension);
    });
}

You have to include these imports to make it work:

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

Consider the hint(s) given in the comments below your question, they are not unimportant!

Upvotes: 0

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