Added output format options enum

src/main/java/rife/bld/extension/CheckstyleFormatOption.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023-2004 the original author or authors.
+ *
+ * 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
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 rife.bld.extension;
+
+/**
+ * The Checkstyle output format for XML, sarif and default (plaib) logger.
+ */
+public enum CheckstyleFormatOption {
+    XML("xml"),
+    SARIF("sarif"),
+    PLAIN("plain");
+
+    public final String label;
+
+    CheckstyleFormatOption(String label) {
+        this.label = label;
+    }
+}

src/main/java/rife/bld/extension/CheckstyleOperation.java

@@ -225,16 +225,17 @@ public class CheckstyleOperation extends AbstractProcessOperation<CheckstyleOper
     }
 
     /**
-     * Specifies the output format. Valid values: {@code xml}, {@code sarif}, {@code plain} for the XML, sarif and
+     * Specifies the output format. Valid values: {@link CheckstyleFormatOption#XML},
-     * default logger respectively. Defaults to {@code plain}.
+     * {@link CheckstyleFormatOption#SARIF}, {@link CheckstyleFormatOption#PLAIN} for the XML, sarif and default logger
+     * respectively.
+     * <p>
+     * Defaults to {@link CheckstyleFormatOption#PLAIN}.
      *
-     * @param format the format
+     * @param format the output format
      * @return the checkstyle operation
      */
-    public CheckstyleOperation format(String format) {
+    public CheckstyleOperation format(CheckstyleFormatOption format) {
-        if (isNotBlank(format)) {
+        options.put("-f", format.label.toLowerCase());
-            options.put("-f", format);
-        }
         return this;
     }