fix: Merged the main branch code and adjusted getRequiredVariables to handle cases where subclasses do not support this method.

Signed-off-by: Sun Yuhan <[email protected]>

Author: sunyuhan1998

spring-ai-commons/src/main/java/org/springframework/ai/template/TemplateRenderer.java

@@ -20,6 +20,8 @@
 import java.util.Set;
 import java.util.function.BiFunction;
 
+import javax.naming.OperationNotSupportedException;
+
 /**
  * Renders a template using a given strategy.
  *
@@ -32,6 +34,8 @@ public interface TemplateRenderer extends BiFunction<String, Map<String, Object>
 	@Override
 	String apply(String template, Map<String, Object> variables);
 
-	Set<String> getRequiredVariables(String template);
+	default Set<String> getRequiredVariables(String template) throws OperationNotSupportedException {
+		throw new OperationNotSupportedException("getRequiredVariables is not supported");
+	}
 
 }

spring-ai-template-st/src/test/java/org/springframework/ai/template/st/StTemplateRendererTests.java

@@ -299,7 +299,6 @@ void shouldRenderTemplateWithBuiltInFunctions() {
 		assertThat(result).isEqualTo("Hello!");
 	}
 
-
 	/**
 	 * Tests that property access syntax like {test.name} is correctly handled. The
 	 * top-level variable 'test' should be identified as required, but 'name' should not.
@@ -351,12 +350,11 @@ void shouldValidatePropertyAccessCorrectly() {
 		missingVariables.put("profile", Map.of("name", "John"));
 
 		assertThatThrownBy(() -> renderer.apply("Hello {user.profile.name}!", missingVariables))
-				.isInstanceOf(IllegalStateException.class)
-				.hasMessageContaining(
-						"Not all variables were replaced in the template. Missing variable names are: [user]");
+			.isInstanceOf(IllegalStateException.class)
+			.hasMessageContaining(
+					"Not all variables were replaced in the template. Missing variable names are: [user]");
 	}
 
-
 	/**
 	 * Test whether the required variables can be correctly extracted from the template.
 	 */