java - Error message: The file "countries.geo.json" is missing or inaccessible

Question

I am taking the Coursera OOP in Java class. In the module 4 assignment, I run the code that the course provides in EarthquakeCityMap.java, and I get an error as "The file "countries.geo.json" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable. Exception in thread "Animation Thread" java.lang.NullPointerException"

I tried to set countryFile as "../data/countries.geo.json", "data/countries.geo.json", and the complete path of countries file, but still didn't solve the problem.

//this error points to the code
private String countryFile = "countries.geo.json";
List<Feature> countries = GeoJSONReader.loadData(this, countryFile);"

//the countries file is saved in data folder.

Poject folder listing

Answer 1

"countries.geo.json" (unless changed in GeoJSONReader manipulates this path) will be relative to the compiled java .class files in the IntelliJ's project out folder.

If this in GeoJSONReader.loadData(this, countryFile); is a PApplet instance you can use sketchPath() to make that path relative to the folder from which the sketch runs:

List<Feature> countries = GeoJSONReader.loadData(this, this.sketchPath("data"+File.separator+countryFile));

The above snippet is based on an assumption so the syntax in your code might be slightly different, but hopefully this illustrates how you'd use sketchPath().

Additionally there's a dataPath() as well which you can test from your main PApplet in setup() as a test:

String fullJSONPath = dataPath("countries.geo.json");
println("fullJSONPath: " + fullJSONPath);//hopefully this prints the full path to the json file on your machine
println(new File(fullJSONPath).exists());//hopefully this prints true