From 7ea603c24cf0aa2635e60d8849d00a8127542942 Mon Sep 17 00:00:00 2001
From: joerg1985 <16140691+joerg1985@users.noreply.github.com>
Date: Wed, 24 Jan 2024 21:25:14 +0100
Subject: [PATCH] Use precompiled regular expressions to validate the segments
 of a UID (#4064)
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Signed-off-by: Jörg Sautter <joerg.sautter@gmx.net>
---
 .../rest/core/internal/item/MetadataSelectorMatcher.java | 3 +--
 .../main/java/org/openhab/core/common/AbstractUID.java   | 9 +++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/item/MetadataSelectorMatcher.java b/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/item/MetadataSelectorMatcher.java
index f1f13df4540..104a53b5415 100644
--- a/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/item/MetadataSelectorMatcher.java
+++ b/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/item/MetadataSelectorMatcher.java
@@ -78,8 +78,7 @@ public Set<String> filterNamespaces(@Nullable String namespaceSelector, @Nullabl
             result.addAll(metadataNamespaces);
 
             // filter all name spaces which do not match the UID segment pattern (this will be the regex tokens):
-            return result.stream().filter(namespace -> namespace.matches(AbstractUID.SEGMENT_PATTERN))
-                    .collect(Collectors.toSet());
+            return result.stream().filter(AbstractUID::isValid).collect(Collectors.toSet());
         }
     }
 }
diff --git a/bundles/org.openhab.core/src/main/java/org/openhab/core/common/AbstractUID.java b/bundles/org.openhab.core/src/main/java/org/openhab/core/common/AbstractUID.java
index 1181151185a..387721c2ca7 100644
--- a/bundles/org.openhab.core/src/main/java/org/openhab/core/common/AbstractUID.java
+++ b/bundles/org.openhab.core/src/main/java/org/openhab/core/common/AbstractUID.java
@@ -14,6 +14,7 @@
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.regex.Pattern;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -26,7 +27,7 @@
 @NonNullByDefault
 public abstract class AbstractUID {
 
-    public static final String SEGMENT_PATTERN = "[\\w-]*";
+    private static final Pattern SEGMENT_PATTERN = Pattern.compile("[\\w-]*");
     public static final String SEPARATOR = ":";
     private final List<String> segments;
     private String uid = "";
@@ -95,8 +96,12 @@ protected String getSegment(int segment) {
         return segments.get(segment);
     }
 
+    public static boolean isValid(@Nullable String segment) {
+        return segment != null && SEGMENT_PATTERN.matcher(segment).matches();
+    }
+
     protected void validateSegment(String segment, int index, int length) {
-        if (!segment.matches(SEGMENT_PATTERN)) {
+        if (!isValid(segment)) {
             throw new IllegalArgumentException(String.format(
                     "ID segment '%s' contains invalid characters. Each segment of the ID must match the pattern %s.",
                     segment, SEGMENT_PATTERN));