How to modify BuildConfig.java on my Android project?

Question

I'm working on an online course and i had these lines of code:

String baseUrl = "http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7";
String apiKey = "&APPID=" + BuildConfig.OPEN_WEATHER_MAP_API_KEY;
URL url = new URL(baseUrl.concat(apiKey));

So, the API key apparently had to be set up on the BuildConfig.java file.

I tried to do that, by adding this line of code to the BuildConfig.java file:

public static final String OPEN_WEATHER_MAP_API_KEY = 111111111111111111;

The first issue is that the string was saved without quotation marks and wouldn't let me compile.

The second, and main issue is that i can't modify that file anymore. Every time i delete the line or add those missing quotation marks, and then try to compile, the line reverts to it's flawed version and compilation stops.

I also get this message when i try to modify BuildConfig.java : "Generated source files should not be edited. The changes will be lost when sources are generated."

Any help will be welcome.

Answer 1

Values in BuildConfig come from the build system. Custom BuildConfig values like OPEN_WEATHER_MAP_API_KEY come from buildConfigField statements in your build.gradle file. The BuildConfig.java file is off of your build/ directory; files in there are generated by the build process and cannot be modified by hand. Instead, examine your build.gradle files and find where your API key is defined.