ISSUE-11242: Fix Java native path param encoding (#11257)

modules/openapi-generator/src/main/resources/Java/libraries/native/ApiClient.mustache

@@ -76,7 +76,7 @@ public class ApiClient {
    * @return URL-encoded representation of the input string.
    */
   public static String urlEncode(String s) {
-    return URLEncoder.encode(s, UTF_8);
+    return URLEncoder.encode(s, UTF_8).replaceAll("\\+", "%20");
   }
 
   /**

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -1228,4 +1228,34 @@ public class JavaClientCodegenTest {
         final Path defaultApi = Paths.get(output + "/src/main/java/xyz/abcdef/ApiClient.java");
         TestUtils.assertFileContains(defaultApi, "value instanceof Map");
     }
+
+    /**
+     * See https://github.com/OpenAPITools/openapi-generator/issues/11242
+     */
+    @Test
+    public void testNativeClientWhiteSpacePathParamEncoding() throws IOException {
+        Map<String, Object> properties = new HashMap<>();
+        properties.put(JavaClientCodegen.JAVA8_MODE, true);
+        properties.put(CodegenConstants.API_PACKAGE, "xyz.abcdef.api");
+
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("java")
+                .setLibrary(JavaClientCodegen.NATIVE)
+                .setAdditionalProperties(properties)
+                .setInputSpec("src/test/resources/3_0/issue11242.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(clientOptInput).generate();
+
+        Assert.assertEquals(files.size(), 34);
+        validateJavaSourceFiles(files);
+
+        TestUtils.assertFileContains(Paths.get(output + "/src/main/java/xyz/abcdef/ApiClient.java"),
+                "public static String urlEncode(String s) { return URLEncoder.encode(s, UTF_8).replaceAll(\"\\\\+\", \"%20\"); }");
+    }
 }

modules/openapi-generator/src/test/resources/3_0/issue11242.yaml

@@ -0,0 +1,37 @@
+openapi: 3.0.3
+info:
+  title: Issue 11242 - Path Param encoding
+  description: "White space encoding in path parameters"
+  version: "1.0.0"
+servers:
+  - url: localhost:8080
+paths:
+  /api/{someParam}:
+    parameters:
+      - in: path
+        name: someParam
+        schema:
+          type: string
+        required: true
+        description: Some parameter.
+    get:
+      operationId: GetSomeParam
+      summary: View some param
+      responses:
+        '200':
+          description: Some return value
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/SomeReturnValue'
+              example:
+                someParam: someValue
+components:
+  schemas:
+    SomeReturnValue:
+      type: object
+      required:
+        - someParam
+      properties:
+        someParam:
+          type: string

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/ApiClient.java

@@ -81,7 +81,7 @@ public class ApiClient {
    * @return URL-encoded representation of the input string.
    */
   public static String urlEncode(String s) {
-    return URLEncoder.encode(s, UTF_8);
+    return URLEncoder.encode(s, UTF_8).replaceAll("\\+", "%20");
   }
 
   /**

samples/client/petstore/java/native/src/main/java/org/openapitools/client/ApiClient.java

@@ -81,7 +81,7 @@ public class ApiClient {
    * @return URL-encoded representation of the input string.
    */
   public static String urlEncode(String s) {
-    return URLEncoder.encode(s, UTF_8);
+    return URLEncoder.encode(s, UTF_8).replaceAll("\\+", "%20");
   }
 
   /**