Add support for artifact recipes as file

src/main/java/org/openrewrite/maven/AbstractRewriteBaseRunMojo.java

@@ -85,10 +85,19 @@ protected ResultsContainer listResults(ExecutionContext ctx) throws MojoExecutio
             }
 
             URLClassLoader recipeArtifactCoordinatesClassloader = getRecipeArtifactCoordinatesClassloader();
+            URLClassLoader fileRecipeFileClassLoader = getRecipeArtifactFileClassloader();
+            Environment env = null;
             if (recipeArtifactCoordinatesClassloader != null) {
                 merge(getClass().getClassLoader(), recipeArtifactCoordinatesClassloader);
+                env = environment(recipeArtifactCoordinatesClassloader);
+            }
+            else if (fileRecipeFileClassLoader != null) {
+                merge(getClass().getClassLoader(), fileRecipeFileClassLoader);
+                env = environment(fileRecipeFileClassLoader);
+            }
+            else {
+                env = environment();
             }
-            Environment env = environment(recipeArtifactCoordinatesClassloader);
 
             Recipe recipe = env.activateRecipes(getActiveRecipes());
             if (recipe.getRecipeList().isEmpty()) {

src/main/java/org/openrewrite/maven/AbstractRewriteMojo.java

@@ -60,7 +60,12 @@ public abstract class AbstractRewriteMojo extends ConfigurableRewriteMojo {
     protected RepositorySystem repositorySystem;
 
     protected Environment environment() throws MojoExecutionException {
-        return environment(getRecipeArtifactCoordinatesClassloader());
+        URLClassLoader classLoader = getRecipeArtifactCoordinatesClassloader();
+        if (classLoader != null) {
+            return environment(classLoader);
+        }
+        classLoader = getRecipeArtifactFileClassloader();
+        return environment(classLoader);
     }
 
     static class Config {
@@ -190,4 +195,35 @@ protected URLClassLoader getRecipeArtifactCoordinatesClassloader() throws MojoEx
                 AbstractRewriteMojo.class.getClassLoader()
         );
     }
+
+    @Nullable
+    protected URLClassLoader getRecipeArtifactFileClassloader() throws MojoExecutionException {
+        if (getRecipeArtifactFiles().isEmpty()) {
+            return null;
+        }
+        ArtifactResolver resolver = new ArtifactResolver(repositorySystem, mavenSession);
+
+        URL[] urls = getRecipeArtifactFiles().stream()
+                .map(File::new)
+                .peek(file -> {
+                    if (!file.exists()) {
+                        throw new RuntimeException("Recipe Artifact file " + file.getPath() + " does not exist");
+                    }
+                })
+                .map(File::toURI)
+                .map(uri -> {
+                    try {
+                        return uri.toURL();
+                    } catch (MalformedURLException e) {
+                        throw new RuntimeException("Failed to resolve artifacts from rewrite.recipeArtifactFiles", e);
+                    }
+                })
+                .toArray(URL[]::new);
+
+        return new URLClassLoader(
+                urls,
+                AbstractRewriteMojo.class.getClassLoader()
+        );
+    }
+
 }

src/main/java/org/openrewrite/maven/ConfigurableRewriteMojo.java

@@ -198,6 +198,10 @@ protected boolean allProjectsMarked() {
     @Parameter(property = "rewrite.recipeArtifactCoordinates")
     private LinkedHashSet<String> recipeArtifactCoordinates;
 
+    @Nullable
+    @Parameter(property = "rewrite.recipeArtifactFiles")
+    private LinkedHashSet<String> recipeArtifactFiles;
+
     @Nullable
     private volatile Set<String> computedRecipes;
 
@@ -207,6 +211,9 @@ protected boolean allProjectsMarked() {
     @Nullable
     private volatile Set<String> computedRecipeArtifactCoordinates;
 
+    @Nullable
+    private volatile Set<String> computedRecipeArtifactFiles;
+
     protected Set<String> getActiveRecipes() {
         if (computedRecipes == null) {
             synchronized (this) {
@@ -292,6 +299,18 @@ protected Set<String> getRecipeArtifactCoordinates() {
         return computedRecipeArtifactCoordinates;
     }
 
+    protected Set<String> getRecipeArtifactFiles() {
+        if (computedRecipeArtifactFiles == null) {
+            synchronized (this) {
+                if (computedRecipeArtifactFiles == null) {
+                    computedRecipeArtifactFiles = getCleanedSet(recipeArtifactFiles);
+                }
+            }
+        }
+        //noinspection ConstantConditions
+        return computedRecipeArtifactFiles;
+    }
+
     private static Set<String> getCleanedSet(@Nullable Set<String> set) {
         if (set == null) {
             return Collections.emptySet();