Index: src/test/java/org/apache/jackrabbit/filevault/maven/packaging/it/ProjectBuilder.java
===================================================================
--- src/test/java/org/apache/jackrabbit/filevault/maven/packaging/it/ProjectBuilder.java	(revision 1816621)
+++ src/test/java/org/apache/jackrabbit/filevault/maven/packaging/it/ProjectBuilder.java	(working copy)
@@ -225,39 +225,41 @@
         if (buildExpectedToFail) {
             return this;
         }
-        ZipFile zip = new ZipFile(testPackageFile);
-        ZipEntry propertiesFile = zip.getEntry("META-INF/vault/properties.xml");
-        assertThat(propertiesFile, notNullValue());
-
-        Properties properties = new Properties();
-        properties.loadFromXML(zip.getInputStream(propertiesFile));
-
-        assertEquals("Property '" + key + "' has correct value", properties.getProperty(key), value);
+        try (ZipFile zip = new ZipFile(testPackageFile)) {
+            ZipEntry propertiesFile = zip.getEntry("META-INF/vault/properties.xml");
+            assertThat(propertiesFile, notNullValue());
+    
+            Properties properties = new Properties();
+            properties.loadFromXML(zip.getInputStream(propertiesFile));
+    
+            assertEquals("Property '" + key + "' has correct value", properties.getProperty(key), value);
+        }
         return this;
     }
 
     public ProjectBuilder verifyExpectedManifest() throws IOException {
         final String expected = FileUtils.fileRead(expectedManifestFile);
-        JarFile jar = new JarFile(testPackageFile);
-        List<String> entries = new ArrayList<String>();
-        for (Map.Entry<Object, Object> e: jar.getManifest().getMainAttributes().entrySet()) {
-            String key = e.getKey().toString();
-            if (IGNORED_MANIFEST_ENTRIES.contains(key)) {
-                continue;
-            }
-            if ("Import-Package".equals(key)) {
-                // split export package so that we have a sorted set
-                Parameters params = new Parameters(e.getValue().toString());
-                for (Map.Entry<String, Attrs> entry : params.entrySet()) {
-                    entries.add(key + ":" + entry.getKey() + ";" + entry.getValue());
+        try (JarFile jar = new JarFile(testPackageFile)) {
+            List<String> entries = new ArrayList<String>();
+            for (Map.Entry<Object, Object> e: jar.getManifest().getMainAttributes().entrySet()) {
+                String key = e.getKey().toString();
+                if (IGNORED_MANIFEST_ENTRIES.contains(key)) {
+                    continue;
                 }
-                continue;
+                if ("Import-Package".equals(key)) {
+                    // split export package so that we have a sorted set
+                    Parameters params = new Parameters(e.getValue().toString());
+                    for (Map.Entry<String, Attrs> entry : params.entrySet()) {
+                        entries.add(key + ":" + entry.getKey() + ";" + entry.getValue());
+                    }
+                    continue;
+                }
+                entries.add(e.getKey() + ":" + e.getValue());
             }
-            entries.add(e.getKey() + ":" + e.getValue());
+            Collections.sort(entries);
+            String result = StringUtils.join(entries.iterator(),"\n");
+            assertEquals("Manifest", expected, result);
         }
-        Collections.sort(entries);
-        String result = StringUtils.join(entries.iterator(),"\n");
-        assertEquals("Manifest", expected, result);
         return this;
     }
 
@@ -280,12 +282,13 @@
         if (buildExpectedToFail) {
             return this;
         }
-        ZipFile zip = new ZipFile(testPackageFile);
-        ZipEntry entry = zip.getEntry("META-INF/vault/filter.xml");
-        assertNotNull("package has a filter.xml", entry);
-        String result = IOUtil.toString(zip.getInputStream(entry), "utf-8");
-        String expected = FileUtils.fileRead(expectedFilterFile);
-        assertEquals("filter.xml is correct", expected, result);
+        try (ZipFile zip = new ZipFile(testPackageFile)) {
+            ZipEntry entry = zip.getEntry("META-INF/vault/filter.xml");
+            assertNotNull("package has a filter.xml", entry);
+            String result = IOUtil.toString(zip.getInputStream(entry), "utf-8");
+            String expected = FileUtils.fileRead(expectedFilterFile);
+            assertEquals("filter.xml is correct", expected, result);
+        }
         return this;
     }