A plugin for displaying geodata stored in a geojson format as a layer in JOSM.
gradle josm
gradle clean build
The following command will build the plugin's jar file, and copy it with the proper name into your JOSM's plugin folder.
gradle installPlugin
And Josm should pick up the plugin at startup.
To Activate it, Josm Preferences > Plugins > Search geojson > Click the check box > Ok.
To open a *.json or *.geojson file, File > Open, select the file, and to make the list appear, click Windows > Geojson