From b959863483dc11140864415fd58c8f449b5bf7c7 Mon Sep 17 00:00:00 2001
From: Greg DiCristofaro <gregd@basistech.com>
Date: Tue, 6 Apr 2021 09:39:26 -0400
Subject: [PATCH 1/2] fix npe on web categories close

---
 .../domaincategorization/WebCategoriesDataModel.java       | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java b/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
index 067a5fceea..0fb3a71ede 100644
--- a/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
+++ b/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
@@ -45,7 +45,6 @@ import java.util.stream.Stream;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.openide.modules.InstalledFileLocator;
-import org.sleuthkit.autopsy.coreutils.NetworkUtils;
 import org.sleuthkit.autopsy.url.analytics.DomainCategory;
 
 /**
@@ -529,7 +528,9 @@ class WebCategoriesDataModel implements AutoCloseable {
 
     @Override
     public synchronized void close() throws SQLException {
-        dbConn.close();
-        dbConn = null;
+        if (dbConn != null) {
+            dbConn.close();
+            dbConn = null;   
+        }
     }
 }

From 3a74f3a2b46fdb5f108c1c980e4e91c2a8b994f3 Mon Sep 17 00:00:00 2001
From: Greg DiCristofaro <gregd@basistech.com>
Date: Tue, 6 Apr 2021 10:13:54 -0400
Subject: [PATCH 2/2] synchronized database access methods

---
 .../domaincategorization/WebCategoriesDataModel.java          | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java b/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
index 0fb3a71ede..5b2932b718 100644
--- a/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
+++ b/Core/src/org/sleuthkit/autopsy/url/analytics/domaincategorization/WebCategoriesDataModel.java
@@ -395,7 +395,7 @@ class WebCategoriesDataModel implements AutoCloseable {
      * @return The list of domain suffixes and their categories.
      * @throws SQLException
      */
-    List<DomainCategory> getRecords() throws SQLException {
+    synchronized List<DomainCategory> getRecords() throws SQLException {
         if (!isInitialized()) {
             initialize();
         }
@@ -427,7 +427,7 @@ class WebCategoriesDataModel implements AutoCloseable {
      * @return The found entry or null.
      * @throws SQLException
      */
-    DomainCategory getRecordBySuffix(String domainSuffix) throws SQLException {
+    synchronized DomainCategory getRecordBySuffix(String domainSuffix) throws SQLException {
         if (!isInitialized()) {
             initialize();
         }