From 5ec934e8ea0622c4b5daa7ebef2e7b34c5bfefdf Mon Sep 17 00:00:00 2001
From: Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Date: Sun, 11 Oct 2026 08:48:10 +0200
Subject: [PATCH] Allow ant javadoc on JDK25+

---
 .github/workflows/main.yml                    |  1 -
 README.md                                     |  2 +-
 .../org/netbeans/nbbuild/SysProperty.java     | 50 +++++++++++++++++++
 nbbuild/default.xml                           |  3 ++
 nbbuild/templates/projectized.xml             |  1 +
 5 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 nbbuild/antsrc/org/netbeans/nbbuild/SysProperty.java

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 3a82021b3d9e..0f831d5b644c 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -468,7 +468,6 @@ jobs:
       - name: Build javadoc
         if: env.test_javadoc == 'true' && success()
         run: |
-          export ANT_OPTS=-Djdk.xml.totalEntitySizeLimit=200000
           ant $OPTS -Djavadoc.fail.broken.links=true build-javadoc
 
       - name: Create Test Summary
diff --git a/README.md b/README.md
index 45e92d3bb0b9..2858441659b4 100644
--- a/README.md
+++ b/README.md
@@ -81,7 +81,7 @@ $ ant javadoc
 ```
 
 #### Notes:
-* On JDK 24 or later, building javadoc may require to raise the jaxp entity limit by setting `export ANT_OPTS=-Djdk.xml.totalEntitySizeLimit=200000`
+
 * Run `javadoc-nb` task in Netbeans to run the javadoc build and display it in a web browser.
 
 ### Running NetBeans
diff --git a/nbbuild/antsrc/org/netbeans/nbbuild/SysProperty.java b/nbbuild/antsrc/org/netbeans/nbbuild/SysProperty.java
new file mode 100644
index 000000000000..06052e1c94e6
--- /dev/null
+++ b/nbbuild/antsrc/org/netbeans/nbbuild/SysProperty.java
@@ -0,0 +1,50 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.netbeans.nbbuild;
+
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
+import org.apache.tools.ant.Task;
+
+/** Sets a system property in the running JVM. Use with care. Needed to
+ * increase XML entities parsing limit before processing out Javadoc with
+ * {@code <ant file="template.xml" .../>}.
+ */
+public final class SysProperty extends Task {
+    private String name;
+    private String value;
+
+    public void setProperty(String name) {
+        this.name = name;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    @Override
+    public void execute() throws BuildException {
+        String current = System.getProperty(name);
+        if (current == null) {
+            System.setProperty(name, value);
+        } else {
+            getProject().log(this, "Not setting property " + name + " as it already has a value " + current, Project.MSG_WARN);
+        }
+    }
+}
diff --git a/nbbuild/default.xml b/nbbuild/default.xml
index f72c31f2b2d3..cb93b6f589cc 100644
--- a/nbbuild/default.xml
+++ b/nbbuild/default.xml
@@ -116,6 +116,9 @@
     <taskdef name="subant-junit" classname="org.netbeans.nbbuild.SubAntJUnitReport" classpath="${nbantext.jar}"/>
     <taskdef name="resolvelist" classname="org.netbeans.nbbuild.ResolveList" classpath="${nbantext.jar}"/>
     <taskdef name="checkmoduleconfigs" classname="org.netbeans.nbbuild.CheckModuleConfigs" classpath="${nbantext.jar}"/>
+    <taskdef name="sysproperty"
+             classname="org.netbeans.nbbuild.SysProperty"
+             classpath="${nbantext.jar}"/>
     <property name="tasks-already-set" value="true"/>
   </target>
 
diff --git a/nbbuild/templates/projectized.xml b/nbbuild/templates/projectized.xml
index 56a3a700cd19..0be30f48c245 100644
--- a/nbbuild/templates/projectized.xml
+++ b/nbbuild/templates/projectized.xml
@@ -405,6 +405,7 @@
 
     <target name="javadoc" depends="build-init,-javadoc-init">
         <path id="javadoc.classpath" refid="processor.cp"/> <!-- #157320 -->
+        <sysproperty property="jdk.xml.totalEntitySizeLimit" value="200000"/>
         <!-- This should become an import at some point, perhaps: -->
         <ant dir="${nb_all}/nbbuild/javadoctools" antfile="template.xml" target="javadoc">
             <property name="javadoc.base" location="."/>