Fix for #89 - Creating a HTML report without violations results in a nullpointer exception

Author: jborgers

src/com/intellij/plugins/bodhi/pmd/PMDInvoker.java

@@ -157,7 +157,7 @@ public void run() {
                 PMDResultPanel resultPanel = projectComponent.getResultPanel();
 
                 PMDRootNode rootNode = resultPanel.getRootNode();
-                PMDResultCollector.report = null;
+                PMDResultCollector.clearReport();
                 rootNode.setFileCount(files.size());
                 rootNode.setRuleSetCount(ruleSetPathArray.length);
                 rootNode.setRunning(true);

src/com/intellij/plugins/bodhi/pmd/PMDResultPanel.java

@@ -31,7 +31,10 @@
 import javax.swing.event.ChangeListener;
 import javax.swing.event.TreeSelectionEvent;
 import javax.swing.event.TreeSelectionListener;
-import javax.swing.tree.*;
+import javax.swing.tree.DefaultMutableTreeNode;
+import javax.swing.tree.DefaultTreeModel;
+import javax.swing.tree.TreeModel;
+import javax.swing.tree.TreePath;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
@@ -310,7 +313,7 @@ public void removeSettingsChangedListener(ChangeListener listener) {
             }
 
             public String getReportText() {
-                Report r = PMDResultCollector.report;
+                Report r = PMDResultCollector.getReport();
                 HTMLRenderer renderer = new HTMLRenderer();
                 StringWriter w = new StringWriter();
                 try {

src/com/intellij/plugins/bodhi/pmd/core/PMDResultCollector.java

@@ -21,16 +21,16 @@
 import java.util.*;
 
 /**
- * Responsible for running PMD and collecting the results which can be represeted in
+ * Responsible for running PMD and collecting the results which can be represented in
  * tree format.
  *
  * @author bodhi
  * @version 1.3
  */
 public class PMDResultCollector {
 
-    private Map<String, PMDBranchNode> ruleNameToNodeMap;
-    public static Report report;
+    private final Map<String, PMDBranchNode> ruleNameToNodeMap;
+    private static Report report = new Report();
 
     /**
      * Creates an instance of PMDResultCollector.
@@ -39,6 +39,20 @@ public PMDResultCollector() {
         ruleNameToNodeMap = new LinkedHashMap<>();
     } // linked to keep insertion order
 
+    /**
+     * Clears the pmd results Report by assigning a new one
+     */
+    public static void clearReport() {
+        report = new Report();
+    }
+
+    /**
+     * Returns the report with pmd results
+     * @return the report with pmd results
+     */
+    public static Report getReport() {
+        return report;
+    }
     /**
      * Runs the given ruleSet(s) on given set of files and returns the result.
      *
@@ -122,7 +136,7 @@ private String shortMessage(String message)
     }
 
     /**
-     * Verifies whether the rule set specified at the path is a valid PMD ruleset.
+     * Verifies whether the rule set specified at the path is a valid PMD rule set.
      *
      * @param path path of the rule set
      * @return true if valid rule set, false otherwise.
@@ -171,7 +185,7 @@ private class PMDResultRenderer extends AbstractIncrementingRenderer {
 
         private final List<PMDBranchNode> pmdRuleResultNodes;
         private final PMDBranchNode processingErrorsNode;
-        private Set<String> filesWithError = new HashSet();
+        private final Set<String> filesWithError = new HashSet<>();
 
         public PMDResultRenderer(List<PMDBranchNode> pmdRuleSetResults, PMDBranchNode errorsNode) {
             super("pmdplugin", "PMD plugin renderer");
@@ -182,9 +196,6 @@ public PMDResultRenderer(List<PMDBranchNode> pmdRuleSetResults, PMDBranchNode er
         @Override
         public void renderFileViolations(Iterator<RuleViolation> violations) throws IOException {
             PMDTreeNodeFactory nodeFactory = PMDTreeNodeFactory.getInstance();
-            if (PMDResultCollector.report == null) {
-                PMDResultCollector.report = new Report();
-            }
             while (violations.hasNext()) {
                 RuleViolation iRuleViolation = violations.next();
                 PMDResultCollector.report.addRuleViolation(iRuleViolation);

src/com/intellij/plugins/bodhi/pmd/handlers/PMDCheckinHandler.java

@@ -42,7 +42,8 @@ public class PMDCheckinHandler extends CheckinHandler {
     @NonNls
     private final CheckinProjectPanel checkinProjectPanel;
 
-    /* default */ PMDCheckinHandler(CheckinProjectPanel checkinProjectPanel) {
+    /* default */
+    PMDCheckinHandler(CheckinProjectPanel checkinProjectPanel) {
         this.checkinProjectPanel = checkinProjectPanel;
     }
 
@@ -102,7 +103,7 @@ public ReturnResult beforeCheckin(@Nullable CommitExecutor executor,
             return ReturnResult.COMMIT;
         }
 
-        PMDResultCollector.report = null;
+        PMDResultCollector.clearReport();
 
         List<PMDBranchNode> ruleSetResultNodes = new ArrayList<>();
         for (String ruleSetPath : plugin.getCustomRuleSetPaths()) {