diff --git a/restlight-core/src/main/java/io/esastack/restlight/core/spi/impl/DefaultStringConverterFactory.java b/restlight-core/src/main/java/io/esastack/restlight/core/spi/impl/DefaultStringConverterFactory.java
index 082f28b6..58f4e80a 100644
--- a/restlight-core/src/main/java/io/esastack/restlight/core/spi/impl/DefaultStringConverterFactory.java
+++ b/restlight-core/src/main/java/io/esastack/restlight/core/spi/impl/DefaultStringConverterFactory.java
@@ -41,9 +41,10 @@ public Optional<StringConverter> createConverter(Key key) {
             @Override
             public Object fromString(String value) {
                 if (converter == null) {
-                    throw new IllegalArgumentException("There is no suitable StringConverter for class(" + key.type() + "),"
-                            + "It should have a constructor that accepts a single String argument or "
-                            + "have a static method named valueOf() or fromString() that accepts a single String argument.");
+                    throw new IllegalArgumentException("There is no suitable StringConverter for class(" +
+                            key.type() + "),It should have a constructor that accepts a single String argument" +
+                            " or have a static method named valueOf() or fromString() that accepts a " +
+                            "single String argument.");
                 }
 
                 return converter.apply(value);