Extracting resources from jar

[nedtwigg]

Following a discussion at diffplug/spotless#744

The way that Blowdryer grabs a resource is this simple interface:

blowdryer/src/main/java/com/diffplug/blowdryer/Blowdryer.java

Lines 176 to 178 in d116192

	static interface ResourcePlugin {
	String toImmutableUrl(String resourcePath);
	}

Which gets initialized in the settings.gradle like this:

blowdryer/src/main/java/com/diffplug/blowdryer/BlowdryerSetup.java

Lines 56 to 62 in d116192

	/** Sets the source where we will grab these scripts. */
	public void github(String repoOrg, GitAnchorType anchorType, String anchor) {
	assertNoLeadingOrTrailingSlash(repoOrg);
	assertNoLeadingOrTrailingSlash(anchor);
	String root = "https://raw.githubusercontent.com/" + repoOrg + "/" + anchor + "/" + repoSubfolder + "/";
	Blowdryer.setResourcePlugin(resource -> root + resource);
	}

This interface could be adapted to extract resources from a jar on the classpath, or you could add credentials for the URL. We're happy to merge PR's which add support for either usecase.

extracting from jar

If you wanted to implement this, the pseudocode might be:

public void localJar(String jarName) {
  File localJar = ... (find jar on classpath with name jarName)
  String rootUrl = "file:///" + localJar.getAbsolutePath() + "!/";
  Blowdryer.setResourcePlugin(resource -> rootUrl + resource);
}

[nedtwigg]

Published in 1.2.0