diff --git a/src/ooxml/java/org/apache/poi/ooxml/util/DocumentHelper.java b/src/ooxml/java/org/apache/poi/ooxml/util/DocumentHelper.java
index cf9fbf71ad..734f169dc1 100644
--- a/src/ooxml/java/org/apache/poi/ooxml/util/DocumentHelper.java
+++ b/src/ooxml/java/org/apache/poi/ooxml/util/DocumentHelper.java
@@ -86,7 +86,7 @@ public final class DocumentHelper {
* @throws IllegalStateException If creating the DocumentBuilder fails, e.g.
* due to {@link ParserConfigurationException}.
*/
- public static synchronized DocumentBuilder newDocumentBuilder() {
+ public static DocumentBuilder newDocumentBuilder() {
try {
DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
documentBuilder.setEntityResolver(SAXHelper.IGNORING_ENTITY_RESOLVER);
diff --git a/src/ooxml/testcases/org/apache/poi/ooxml/util/TestDocumentHelper.java b/src/ooxml/testcases/org/apache/poi/ooxml/util/TestDocumentHelper.java
index 63c6610f7e..9ffb78627a 100644
--- a/src/ooxml/testcases/org/apache/poi/ooxml/util/TestDocumentHelper.java
+++ b/src/ooxml/testcases/org/apache/poi/ooxml/util/TestDocumentHelper.java
@@ -22,6 +22,9 @@ import org.xml.sax.InputSource;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import java.io.ByteArrayInputStream;
+import java.util.ArrayList;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
import static org.junit.Assert.*;
@@ -35,6 +38,21 @@ public class TestDocumentHelper {
documentBuilder.parse(new InputSource(new ByteArrayInputStream("".getBytes("UTF-8"))));
}
+ @Test
+ public void testCreatingManyDocumentBuilders() throws Exception {
+ int limit = 1000;
+ ArrayList> futures = new ArrayList<>();
+ for(int i = 0; i < limit; i++) {
+ futures.add(CompletableFuture.supplyAsync(() -> {
+ return DocumentHelper.newDocumentBuilder();
+ }));
+ }
+ for(CompletableFuture future : futures) {
+ DocumentBuilder documentBuilder = future.get(10, TimeUnit.SECONDS);
+ assertTrue(documentBuilder.isNamespaceAware());
+ }
+ }
+
@Test
public void testDocumentBuilderFactory() throws Exception {
try {