diff --git a/unknow-server-maven/src/main/java/unknow/server/maven/jaxrs/OpenApiBuilder.java b/unknow-server-maven/src/main/java/unknow/server/maven/jaxrs/OpenApiBuilder.java
index 423cd0cc..19df28a1 100644
--- a/unknow-server-maven/src/main/java/unknow/server/maven/jaxrs/OpenApiBuilder.java
+++ b/unknow-server-maven/src/main/java/unknow/server/maven/jaxrs/OpenApiBuilder.java
@@ -70,9 +70,9 @@ private static Schema<?> getDefault(String n) {
 			case "java.lang.Byte":
 				return new Schema<>().type(INTEGER).minimum(BigDecimal.valueOf(Byte.MIN_VALUE)).maximum(BigDecimal.valueOf(Byte.MAX_VALUE));
 			case "char":
-				return new Schema<>().type("string").maxLength(1).minLength(1).nullable(false);
+				return new Schema<>().type(STRING).maxLength(1).minLength(1).nullable(false);
 			case "java.lang.Character":
-				return new Schema<>().type("string").maxLength(1).minLength(1);
+				return new Schema<>().type(STRING).maxLength(1).minLength(1);
 			case "short":
 				return new Schema<>().type(INTEGER).minimum(BigDecimal.valueOf(Short.MIN_VALUE)).maximum(BigDecimal.valueOf(Short.MAX_VALUE)).nullable(false);
 			case "java.lang.Short":