Encode BPMN XSD URL so schema validation works on non-ASCII paths

modules/flowable-bpmn-converter/src/main/java/org/flowable/bpmn/converter/BpmnXMLConverter.java

@@ -17,6 +17,10 @@
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.io.UnsupportedEncodingException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -248,19 +252,23 @@ public void validateModel(XMLStreamReader xmlStreamReader) throws Exception {
 
     protected Schema createSchema() throws SAXException {
         SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
-        Schema schema = null;
+        URL xsdUrl = null;
         if (classloader != null) {
-            schema = factory.newSchema(classloader.getResource(BPMN_XSD));
+            xsdUrl = classloader.getResource(BPMN_XSD);
         }
-
-        if (schema == null) {
-            schema = factory.newSchema(BpmnXMLConverter.class.getClassLoader().getResource(BPMN_XSD));
+        if (xsdUrl == null) {
+            xsdUrl = BpmnXMLConverter.class.getClassLoader().getResource(BPMN_XSD);
         }
-
-        if (schema == null) {
+        if (xsdUrl == null) {
             throw new XMLException("BPMN XSD could not be found");
         }
-        return schema;
+        try {
+            // Xerces cannot resolve xsd:include/import against a schema URL whose path contains
+            // non-ASCII characters unless the URL is ASCII-encoded.
+            return factory.newSchema(URI.create(xsdUrl.toURI().toASCIIString()).toURL());
+        } catch (MalformedURLException | URISyntaxException e) {
+            return factory.newSchema(xsdUrl);
+        }
     }
 
     public BpmnModel convertToBpmnModel(InputStreamProvider inputStreamProvider, boolean validateSchema, boolean enableSafeBpmnXml) {

modules/flowable-bpmn-converter/src/test/java/org/flowable/editor/language/xml/NonAsciiClasspathSchemaValidationTest.java

@@ -0,0 +1,102 @@
+/* Licensed 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.flowable.editor.language.xml;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Comparator;
+import java.util.List;
+
+import org.flowable.bpmn.converter.BpmnXMLConverter;
+import org.flowable.bpmn.model.BpmnModel;
+import org.flowable.common.engine.impl.util.io.InputStreamSource;
+import org.junit.jupiter.api.Test;
+
+class NonAsciiClasspathSchemaValidationTest {
+
+    private static final String XSD_PACKAGE = "org/flowable/impl/bpmn/parser/";
+    private static final List<String> SCHEMA_FILES = List.of(
+            "BPMN20.xsd", "BPMNDI.xsd", "Semantic.xsd", "DC.xsd", "DI.xsd");
+
+    private static final String MINIMAL_BPMN = """
+            <?xml version="1.0" encoding="UTF-8"?>
+            <definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+                         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                         targetNamespace="http://example.com/process">
+              <process id="process1" isExecutable="true">
+                <startEvent id="start" />
+              </process>
+            </definitions>
+            """;
+
+    @Test
+    void shouldValidateSchemaWhenXsdIsLoadedFromNonAsciiPath() throws Exception {
+        Path tempDir = Files.createTempDirectory("flowable-流程-");
+        try {
+            Path parserDir = tempDir.resolve(XSD_PACKAGE);
+            Files.createDirectories(parserDir);
+            ClassLoader runtimeLoader = BpmnXMLConverter.class.getClassLoader();
+            for (String name : SCHEMA_FILES) {
+                try (InputStream in = runtimeLoader.getResourceAsStream(XSD_PACKAGE + name)) {
+                    assertThat(in).as(name).isNotNull();
+                    Files.copy(in, parserDir.resolve(name));
+                }
+            }
+
+            URL rawFileUrl = new URL("file:" + parserDir.resolve("BPMN20.xsd").toAbsolutePath());
+            ClassLoader classLoader = new ClassLoader(runtimeLoader) {
+                @Override
+                public URL getResource(String name) {
+                    if ((XSD_PACKAGE + "BPMN20.xsd").equals(name)) {
+                        return rawFileUrl;
+                    }
+                    return super.getResource(name);
+                }
+            };
+
+            BpmnXMLConverter converter = new BpmnXMLConverter();
+            converter.setClassloader(classLoader);
+
+            BpmnModel model = converter.convertToBpmnModel(
+                    new InputStreamSource(new ByteArrayInputStream(MINIMAL_BPMN.getBytes(StandardCharsets.UTF_8))),
+                    true, false, "UTF-8");
+
+            assertThat(model).isNotNull();
+            assertThat(model.getMainProcess().getId()).isEqualTo("process1");
+        } finally {
+            deleteRecursively(tempDir);
+        }
+    }
+
+    private static void deleteRecursively(Path root) throws IOException {
+        if (root == null || !Files.exists(root)) {
+            return;
+        }
+        try (var paths = Files.walk(root)) {
+            paths.sorted(Comparator.reverseOrder()).forEach(path -> {
+                try {
+                    Files.deleteIfExists(path);
+                } catch (IOException ignored) {
+                    // best-effort cleanup of the temp schema copy
+                }
+            });
+        }
+    }
+}