make methods static when possible

Author: JuditKnoll

src/main/groovy/org/codehaus/mojo/spotbugs/ResourceHelper.groovy

@@ -124,7 +124,7 @@ final class ResourceHelper {
         return outputResourcePath
     }
 
-    private createParentDirectories(Path outputResourcePath) {
+    private static createParentDirectories(Path outputResourcePath) {
         Path parent = outputResourcePath.getParent()
         if (parent != null && Files.notExists(parent)) {
             Files.createDirectories(parent)

src/main/groovy/org/codehaus/mojo/spotbugs/SourceFileIndexer.groovy

@@ -135,7 +135,7 @@ class SourceFileIndexer {
      * @param path Path to clean up
      * @return Path safe to use for comparison
      */
-    private String normalizePath(String path) {
+    private static String normalizePath(String path) {
         return path.replace('\\', '/')
     }
 

src/main/groovy/org/codehaus/mojo/spotbugs/SpotBugsMojo.groovy

@@ -1071,7 +1071,7 @@ class SpotBugsMojo extends AbstractMavenReport implements SpotBugsPluginsTrait {
      *
      * @param file Destination file to create.
      */
-    private void forceFileCreation(File file) {
+    private static void forceFileCreation(File file) {
         if (file.exists()) {
             file.delete()
         }

src/main/groovy/org/codehaus/mojo/spotbugs/XDocsReporter.groovy

@@ -87,7 +87,7 @@ class XDocsReporter {
      *            The ThresholdValue integer to evaluate.
      * @return The string valueof the Threshold object.
      */
-    protected String evaluateThresholdParameter(String thresholdValue) {
+    protected static String evaluateThresholdParameter(String thresholdValue) {
         switch (thresholdValue) {
             case '1': return 'High'
             case '2': return 'Normal'
@@ -103,7 +103,7 @@ class XDocsReporter {
      *
      * @return The Spotbugs Version used on the report.
      */
-    protected String getSpotBugsVersion() {
+    protected static String getSpotBugsVersion() {
         return Version.VERSION_STRING
     }