Use String[] instead of Array as lambda type

src/main/java/org/openrewrite/java/template/processor/RefasterTemplateProcessor.java

@@ -675,7 +675,7 @@ private String toLambda(JCTree.JCMethodDecl method) {
 
         StringJoiner joiner = new StringJoiner(", ", "(", ")");
         for (JCTree.JCVariableDecl parameter : method.getParameters()) {
-            String paramType = parameter.getType().type.tsym.getQualifiedName().toString();
+            String paramType = parameter.getType().type.toString();
             if (!getBoxedPrimitive(paramType).equals(paramType)) {
                 paramType = "@Primitive " + getBoxedPrimitive(paramType);
             } else if (paramType.startsWith("java.lang.")) {

src/main/java/org/openrewrite/java/template/processor/TemplateProcessor.java

@@ -208,7 +208,7 @@ public void visitIdent(JCTree.JCIdent ident) {
                                 for (JCTree.JCVariableDecl parameter : parameters) {
                                     if (parameter.type.tsym instanceof Symbol.ClassSymbol) {
                                         String paramType = parameter.type.tsym.getQualifiedName().toString();
-                                        if (!paramType.startsWith("java.lang")) {
+                                        if (!paramType.startsWith("java.lang") && !"Array".equals(paramType)) {
                                             out.write("import " + paramType + ";\n");
                                         }
                                     }

src/test/java/org/openrewrite/java/template/RefasterTemplateProcessorTest.java

@@ -35,6 +35,7 @@
 class RefasterTemplateProcessorTest {
     @ParameterizedTest
     @ValueSource(strings = {
+      "Arrays",
       "MethodThrows",
       "NestedPreconditions",
       "ParameterReuse",

src/test/resources/refaster/Arrays.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2023 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package foo;
+
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+
+public class Arrays {
+    @BeforeTemplate
+    String before(String[] strings) {
+        return String.join(", ", strings);
+    }
+
+    @AfterTemplate
+    String after(String[] strings) {
+        return String.join(":", strings);
+    }
+}

src/test/resources/refaster/ArraysRecipe.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2023 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package foo;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.internal.lang.NonNullApi;
+import org.openrewrite.java.JavaTemplate;
+import org.openrewrite.java.JavaVisitor;
+import org.openrewrite.java.search.*;
+import org.openrewrite.java.template.Primitive;
+import org.openrewrite.java.template.Semantics;
+import org.openrewrite.java.template.function.*;
+import org.openrewrite.java.template.internal.AbstractRefasterJavaVisitor;
+import org.openrewrite.java.tree.*;
+
+import java.util.*;
+
+import static org.openrewrite.java.template.internal.AbstractRefasterJavaVisitor.EmbeddingOption.*;
+
+@SuppressWarnings("all")
+@NonNullApi
+public class ArraysRecipe extends Recipe {
+
+    public ArraysRecipe() {
+    }
+
+    @Override
+    public String getDisplayName() {
+        return "Refaster template `Arrays`";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Recipe created for the following Refaster template:\n```java\npublic class Arrays {\n    \n    @BeforeTemplate()\n    String before(String[] strings) {\n        return String.join(\", \", strings);\n    }\n    \n    @AfterTemplate()\n    String after(String[] strings) {\n        return String.join(\":\", strings);\n    }\n}\n```\n.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        JavaVisitor<ExecutionContext> javaVisitor = new AbstractRefasterJavaVisitor() {
+            final JavaTemplate before = Semantics.expression(this, "before", (String[] strings) -> String.join(", ", strings)).build();
+            final JavaTemplate after = Semantics.expression(this, "after", (String[] strings) -> String.join(":", strings)).build();
+
+            @Override
+            public J visitMethodInvocation(J.MethodInvocation elem, ExecutionContext ctx) {
+                JavaTemplate.Matcher matcher;
+                if ((matcher = before.matcher(getCursor())).find()) {
+                    return embed(
+                            after.apply(getCursor(), elem.getCoordinates().replace(), matcher.parameter(0)),
+                            getCursor(),
+                            ctx,
+                            SHORTEN_NAMES
+                    );
+                }
+                return super.visitMethodInvocation(elem, ctx);
+            }
+
+        };
+        return Preconditions.check(
+                new UsesMethod<>("java.lang.String join(..)"),
+                javaVisitor
+        );
+    }
+}