From ea3461138c01be3e647ef7520be071b99047f812 Mon Sep 17 00:00:00 2001
From: Khaled Yakdan <yakdan@code-intelligence.com>
Date: Wed, 19 Oct 2022 22:05:57 +0200
Subject: [PATCH] Refactor the JXPathFilter

---
 .../apache/commons/jxpath/ri/JXPathFilter.java   | 16 ++++++----------
 .../commons/jxpath/ri/model/JXPath154Test.java   | 12 ++++++++++++
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/main/java/org/apache/commons/jxpath/ri/JXPathFilter.java b/src/main/java/org/apache/commons/jxpath/ri/JXPathFilter.java
index 92554ed9b..e5fe2ff78 100644
--- a/src/main/java/org/apache/commons/jxpath/ri/JXPathFilter.java
+++ b/src/main/java/org/apache/commons/jxpath/ri/JXPathFilter.java
@@ -22,22 +22,18 @@
 
 /**
  * A filter to be used by JXPath, to evaluate the xpath string values to impose any restrictions.
- * This class implements specific filter interfaces, and implements methods in those. 
+ * This class implements specific filter interfaces, and implements methods in those.
  * For instance, it JXPathClassFilter interface, which is used to check if any restricted java classes are passed via xpath
  * JXPath uses this filter instance when an extension function instance is created.
  */
 public class JXPathFilter implements JXPathClassFilter {
-    private Set<String> allowedClassesList = null;
+    private final Set<String> allowedClasses;
 
     public JXPathFilter() {
-        init();
-    }
-
-    public void init() {
+        this.allowedClasses = new HashSet<>();
         final String allowedClasses = System.getProperty("jxpath.class.allow");
         if (allowedClasses != null && !allowedClasses.isEmpty()) {
-            allowedClassesList = new HashSet<>();
-            allowedClassesList.addAll(Arrays.asList(allowedClasses.split(",")));
+            this.allowedClasses.addAll(Arrays.asList(allowedClasses.split(",")));
         }
     }
 
@@ -50,10 +46,10 @@ public void init() {
      */
     @Override
     public boolean exposeToXPath(String className) {
-        if (allowedClassesList == null || allowedClassesList.size() < 1) {
+        if (allowedClasses.isEmpty()) {
             return false;
         }
 
-        return allowedClassesList.contains(className) || allowedClassesList.contains("*");
+        return allowedClasses.contains(className) || allowedClasses.contains("*");
     }
 }
diff --git a/src/test/java/org/apache/commons/jxpath/ri/model/JXPath154Test.java b/src/test/java/org/apache/commons/jxpath/ri/model/JXPath154Test.java
index eff6253eb..7352365c9 100644
--- a/src/test/java/org/apache/commons/jxpath/ri/model/JXPath154Test.java
+++ b/src/test/java/org/apache/commons/jxpath/ri/model/JXPath154Test.java
@@ -25,6 +25,18 @@ public class JXPath154Test extends JXPathTestCase {
 
     protected JXPathContext context;
 
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        System.setProperty("jxpath.class.allow", "*");
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        System.clearProperty("jxpath.class.allow");
+        super.tearDown();
+    }
+
     protected DocumentContainer createDocumentContainer(final String model) {
         return new DocumentContainer(JXPathTestCase.class.getResource("InnerEmptyNamespace.xml"), model);
     }