diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BasePropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BasePropertyValidator.java
index d3255b5..8350810 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BasePropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BasePropertyValidator.java
@@ -100,6 +100,10 @@ public abstract class BasePropertyValidator<T, TProperty, TPropertyValidator ext
     // #region - isNull
     // ================================
 
+    public TPropertyValidator isNull() {
+        return isNull("The input must be null.");
+    }
+
     public TPropertyValidator isNull(String errMsg) {
         return isNull(convertExceptionCreator(errMsg));
     }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/CollectionPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/CollectionPropertyValidator.java
index 9309f55..8b657e4 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/CollectionPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/CollectionPropertyValidator.java
@@ -31,11 +31,16 @@ public class CollectionPropertyValidator<T, TElement>
 
     // ====== notEmpty =====
 
+    public CollectionPropertyValidator<T, TElement> notEmpty() {
+        return notEmpty("The input must not be empty.");
+    }
+
     public CollectionPropertyValidator<T, TElement> notEmpty(String errMsg) {
         return notEmpty(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> notEmpty(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> notEmpty(
+            Supplier<E> exceptionCreator) {
         return notEmpty(convertExceptionCreator(exceptionCreator));
     }
 
@@ -47,11 +52,16 @@ public class CollectionPropertyValidator<T, TElement>
 
     // ====== isEmpty =====
 
+    public CollectionPropertyValidator<T, TElement> isEmpty() {
+        return isEmpty("The input must be empty.");
+    }
+
     public CollectionPropertyValidator<T, TElement> isEmpty(String errMsg) {
         return isEmpty(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> isEmpty(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> isEmpty(
+            Supplier<E> exceptionCreator) {
         return isEmpty(convertExceptionCreator(exceptionCreator));
     }