diff --git a/plusone-validator/pom.xml b/plusone-validator/pom.xml
index 6fcfa08..8ce1f6a 100644
--- a/plusone-validator/pom.xml
+++ b/plusone-validator/pom.xml
@@ -16,7 +16,7 @@
   <url>http://zhouxy.xyz</url>
 
   <description>
-    Plusone Validator 是一个参数校验框架，可针对 DTO 创建对应的校验器，并复用该校验器实例，对 DTO 进行校验。
+    Plusone Validator 是一个校验库，用于构建校验规则对对象（尤其是入参）进行校验。API 参考自 .NET 的 FluentValidation。
   </description>
 
   <properties>
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BaseComparablePropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BaseComparablePropertyValidator.java
index a6c90ba..52ba86f 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BaseComparablePropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BaseComparablePropertyValidator.java
@@ -21,19 +21,17 @@ import java.util.function.Supplier;
 
 import com.google.common.collect.Range;
 
-public abstract
-class BaseComparablePropertyValidator<TObj,
-                                      TProperty extends Comparable<TProperty>,
-                                      TPropertyValidator extends BaseComparablePropertyValidator<TObj, TProperty, TPropertyValidator>>
-        extends BasePropertyValidator<TObj, TProperty, TPropertyValidator> {
+public abstract class BaseComparablePropertyValidator<T, TProperty extends Comparable<TProperty>, TPropertyValidator extends BaseComparablePropertyValidator<T, TProperty, TPropertyValidator>>
+        extends BasePropertyValidator<T, TProperty, TPropertyValidator> {
 
-    BaseComparablePropertyValidator(Function<TObj, ? extends TProperty> getter) {
+    BaseComparablePropertyValidator(Function<T, ? extends TProperty> getter) {
         super(getter);
     }
 
     public TPropertyValidator inRange(Range<TProperty> range) {
         withRule(value -> value != null && range.contains(value),
-                convertExceptionCreator("The value is not in the interval " + range.toString()));
+                value -> new IllegalArgumentException(
+                        String.format("The input must in the interval %s. You entered %s.", range, value)));
         return thisObject();
     }
 
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 47e8621..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
@@ -25,16 +25,13 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
-public abstract class BasePropertyValidator< //
-        TObj, //
-        TProperty, //
-        TPropertyValidator extends BasePropertyValidator<TObj, TProperty, TPropertyValidator>> {
+public abstract class BasePropertyValidator<T, TProperty, TPropertyValidator extends BasePropertyValidator<T, TProperty, TPropertyValidator>> {
 
-    private final Function<TObj, ? extends TProperty> getter;
+    private final Function<T, ? extends TProperty> getter;
 
     private final List<Consumer<? super TProperty>> consumers = new LinkedList<>();
 
-    protected BasePropertyValidator(Function<TObj, ? extends TProperty> getter) {
+    protected BasePropertyValidator(Function<T, ? extends TProperty> getter) {
         this.getter = getter;
     }
 
@@ -62,7 +59,7 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
-    public final <T extends TObj> void validate(T obj) {
+    public final void validate(T obj) {
         for (Consumer<? super TProperty> consumer : consumers) {
             consumer.accept(getter.apply(obj));
         }
@@ -74,10 +71,12 @@ public abstract class BasePropertyValidator< //
     // ====== Object ======
     // ====================
 
-    // ====== notNull =====
+    // ================================
+    // #region - notNull
+    // ================================
 
     public TPropertyValidator notNull() {
-        return notNull("Value could not be null.");
+        return notNull("The input must not be null.");
     }
 
     public TPropertyValidator notNull(String errMsg) {
@@ -93,7 +92,17 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
-    // ====== isNull =====
+    // ================================
+    // #endregion - notNull
+    // ================================
+
+    // ================================
+    // #region - isNull
+    // ================================
+
+    public TPropertyValidator isNull() {
+        return isNull("The input must be null.");
+    }
 
     public TPropertyValidator isNull(String errMsg) {
         return isNull(convertExceptionCreator(errMsg));
@@ -108,10 +117,17 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
-    // ===== equals =====
+    // ================================
+    // #endregion - isNull
+    // ================================
+
+    // ================================
+    // #region - equals
+    // ================================
 
     public TPropertyValidator equalsThat(Object that) {
-        return equalsThat(that, value -> new IllegalArgumentException(String.format("(%s) 必须与 (%s) 相等", value, that)));
+        return equalsThat(that,
+                value -> new IllegalArgumentException(String.format("The input must be equal to '%s'.", that)));
     }
 
     public TPropertyValidator equalsThat(Object that, String errMsg) {
@@ -129,10 +145,16 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
-    // ===== must =====
+    // ================================
+    // #endregion - equals
+    // ================================
+
+    // ================================
+    // #region - must
+    // ================================
 
     public TPropertyValidator must(Predicate<? super TProperty> condition) {
-        return must(condition, "无效的用户输入");
+        return must(condition, "The specified condition was not met for the input.");
     }
 
     public TPropertyValidator must(Predicate<? super TProperty> condition, String errMsg) {
@@ -152,10 +174,8 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
-    // ===== must =====
-
     public TPropertyValidator must(Collection<Predicate<? super TProperty>> conditions) {
-        return must(conditions, "无效的用户输入");
+        return must(conditions, "The specified conditions were not met for the input.");
     }
 
     public TPropertyValidator must(Collection<Predicate<? super TProperty>> conditions, String errMsg) {
@@ -177,6 +197,10 @@ public abstract class BasePropertyValidator< //
         return thisObject();
     }
 
+    // ================================
+    // #endregion - must
+    // ================================
+
     static <V> Function<V, IllegalArgumentException> convertExceptionCreator(String errMsg) {
         return value -> new IllegalArgumentException(errMsg);
     }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BoolPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BoolPropertyValidator.java
index da807e3..2357381 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BoolPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/BoolPropertyValidator.java
@@ -19,28 +19,28 @@ package xyz.zhouxy.plusone.validator;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-public class BoolPropertyValidator<DTO> extends BasePropertyValidator<DTO, Boolean, BoolPropertyValidator<DTO>> {
+public class BoolPropertyValidator<T> extends BasePropertyValidator<T, Boolean, BoolPropertyValidator<T>> {
 
-    BoolPropertyValidator(Function<DTO, Boolean> getter) {
+    BoolPropertyValidator(Function<T, Boolean> getter) {
         super(getter);
     }
 
     // ====== isTrueValue ======
 
-    public BoolPropertyValidator<DTO> isTrueValue() {
-        return isTrueValue("The value must be true.");
+    public BoolPropertyValidator<T> isTrueValue() {
+        return isTrueValue("The input must be true.");
     }
 
-    public BoolPropertyValidator<DTO> isTrueValue(String errMsg) {
+    public BoolPropertyValidator<T> isTrueValue(String errMsg) {
         return isTrueValue(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> BoolPropertyValidator<DTO> isTrueValue(
+    public <E extends RuntimeException> BoolPropertyValidator<T> isTrueValue(
             Supplier<E> exceptionCreator) {
         return isTrueValue(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> BoolPropertyValidator<DTO> isTrueValue(
+    public <E extends RuntimeException> BoolPropertyValidator<T> isTrueValue(
             Function<Boolean, E> exceptionCreator) {
         withRule(Boolean.TRUE::equals, exceptionCreator);
         return this;
@@ -48,27 +48,27 @@ public class BoolPropertyValidator<DTO> extends BasePropertyValidator<DTO, Boole
 
     // ====== isFalseValue ======
 
-    public BoolPropertyValidator<DTO> isFalseValue() {
-        return isFalseValue("The value must be false.");
+    public BoolPropertyValidator<T> isFalseValue() {
+        return isFalseValue("The input must be false.");
     }
 
-    public BoolPropertyValidator<DTO> isFalseValue(String errMsg) {
+    public BoolPropertyValidator<T> isFalseValue(String errMsg) {
         return isFalseValue(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> BoolPropertyValidator<DTO> isFalseValue(
+    public <E extends RuntimeException> BoolPropertyValidator<T> isFalseValue(
             Supplier<E> exceptionCreator) {
         return isFalseValue(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> BoolPropertyValidator<DTO> isFalseValue(
+    public <E extends RuntimeException> BoolPropertyValidator<T> isFalseValue(
             Function<Boolean, E> exceptionCreator) {
         withRule(Boolean.FALSE::equals, exceptionCreator);
         return this;
     }
 
     @Override
-    protected BoolPropertyValidator<DTO> thisObject() {
+    protected BoolPropertyValidator<T> thisObject() {
         return this;
     }
 }
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 1379e32..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
@@ -22,47 +22,57 @@ import java.util.function.Supplier;
 
 import xyz.zhouxy.plusone.commons.collection.CollectionTools;
 
-public class CollectionPropertyValidator<DTO, T>
-        extends BasePropertyValidator<DTO, Collection<T>, CollectionPropertyValidator<DTO, T>> {
+public class CollectionPropertyValidator<T, TElement>
+        extends BasePropertyValidator<T, Collection<TElement>, CollectionPropertyValidator<T, TElement>> {
 
-    CollectionPropertyValidator(Function<DTO, Collection<T>> getter) {
+    CollectionPropertyValidator(Function<T, Collection<TElement>> getter) {
         super(getter);
     }
 
     // ====== notEmpty =====
 
-    public CollectionPropertyValidator<DTO, T> notEmpty(String errMsg) {
+    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<DTO, T> notEmpty(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> notEmpty(
+            Supplier<E> exceptionCreator) {
         return notEmpty(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> CollectionPropertyValidator<DTO, T> notEmpty(
-            Function<Collection<T>, E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> notEmpty(
+            Function<Collection<TElement>, E> exceptionCreator) {
         withRule(CollectionTools::isNotEmpty, exceptionCreator);
         return this;
     }
 
     // ====== isEmpty =====
 
-    public CollectionPropertyValidator<DTO, T> isEmpty(String errMsg) {
+    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<DTO, T> isEmpty(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> isEmpty(
+            Supplier<E> exceptionCreator) {
         return isEmpty(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> CollectionPropertyValidator<DTO, T> isEmpty(
-            Function<Collection<T>, E> exceptionCreator) {
+    public <E extends RuntimeException> CollectionPropertyValidator<T, TElement> isEmpty(
+            Function<Collection<TElement>, E> exceptionCreator) {
         withRule(CollectionTools::isEmpty, exceptionCreator);
         return this;
     }
 
     @Override
-    protected CollectionPropertyValidator<DTO, T> thisObject() {
+    protected CollectionPropertyValidator<T, TElement> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ComparablePropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ComparablePropertyValidator.java
index 22b6e70..3fc8820 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ComparablePropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ComparablePropertyValidator.java
@@ -18,15 +18,15 @@ package xyz.zhouxy.plusone.validator;
 
 import java.util.function.Function;
 
-public class ComparablePropertyValidator<TObj, TProperty extends Comparable<TProperty>>
-        extends BaseComparablePropertyValidator<TObj, TProperty, ComparablePropertyValidator<TObj, TProperty>> {
+public class ComparablePropertyValidator<T, TProperty extends Comparable<TProperty>>
+        extends BaseComparablePropertyValidator<T, TProperty, ComparablePropertyValidator<T, TProperty>> {
 
-    ComparablePropertyValidator(Function<TObj, ? extends TProperty> getter) {
+    ComparablePropertyValidator(Function<T, ? extends TProperty> getter) {
         super(getter);
     }
 
     @Override
-    protected ComparablePropertyValidator<TObj, TProperty> thisObject() {
+    protected ComparablePropertyValidator<T, TProperty> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/DoublePropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/DoublePropertyValidator.java
index d8fd23c..646993d 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/DoublePropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/DoublePropertyValidator.java
@@ -19,10 +19,10 @@ package xyz.zhouxy.plusone.validator;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-public class DoublePropertyValidator<DTO>
-        extends BaseComparablePropertyValidator<DTO, Double, DoublePropertyValidator<DTO>> {
+public class DoublePropertyValidator<T>
+        extends BaseComparablePropertyValidator<T, Double, DoublePropertyValidator<T>> {
 
-    DoublePropertyValidator(Function<DTO, Double> getter) {
+    DoublePropertyValidator(Function<T, Double> getter) {
         super(getter);
     }
 
@@ -30,20 +30,20 @@ public class DoublePropertyValidator<DTO>
     // #region - greater than
     // ================================
 
-    public DoublePropertyValidator<DTO> gt(double min) {
-        return gt(min, String.format("The value should be greater than %s", min));
+    public DoublePropertyValidator<T> gt(double min) {
+        return gt(min, String.format("The input must be greater than '%s'.", min));
     }
 
-    public DoublePropertyValidator<DTO> gt(double min, String errMsg) {
+    public DoublePropertyValidator<T> gt(double min, String errMsg) {
         return gt(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> gt(
+    public <E extends RuntimeException> DoublePropertyValidator<T> gt(
             double min, Supplier<E> exceptionCreator) {
         return gt(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> gt(
+    public <E extends RuntimeException> DoublePropertyValidator<T> gt(
             double min, Function<Double, E> exceptionCreator) {
         withRule(value -> (value != null && value > min), exceptionCreator);
         return this;
@@ -57,20 +57,20 @@ public class DoublePropertyValidator<DTO>
     // #region - greater than or equal to
     // ================================
 
-    public DoublePropertyValidator<DTO> ge(double min) {
-        return ge(min, String.format("The value should be greater than or equal to %s", min));
+    public DoublePropertyValidator<T> ge(double min) {
+        return ge(min, String.format("The input must be greater than or equal to '%s'.", min));
     }
 
-    public DoublePropertyValidator<DTO> ge(double min, String errMsg) {
+    public DoublePropertyValidator<T> ge(double min, String errMsg) {
         return ge(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> ge(
+    public <E extends RuntimeException> DoublePropertyValidator<T> ge(
             double min, Supplier<E> exceptionCreator) {
         return ge(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> ge(
+    public <E extends RuntimeException> DoublePropertyValidator<T> ge(
             double min, Function<Double, E> exceptionCreator) {
         withRule(value -> (value != null && value >= min), exceptionCreator);
         return this;
@@ -84,20 +84,20 @@ public class DoublePropertyValidator<DTO>
     // #region - less than
     // ================================
 
-    public DoublePropertyValidator<DTO> lt(double max) {
-        return lt(max, String.format("The value should be less than %s", max));
+    public DoublePropertyValidator<T> lt(double max) {
+        return lt(max, String.format("The input must be less than '%s'.", max));
     }
 
-    public DoublePropertyValidator<DTO> lt(double max, String errMsg) {
+    public DoublePropertyValidator<T> lt(double max, String errMsg) {
         return lt(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> lt(
+    public <E extends RuntimeException> DoublePropertyValidator<T> lt(
             double max, Supplier<E> exceptionCreator) {
         return lt(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> lt(
+    public <E extends RuntimeException> DoublePropertyValidator<T> lt(
             double max, Function<Double, E> exceptionCreator) {
         withRule(value -> (value != null && value < max), exceptionCreator);
         return this;
@@ -111,20 +111,20 @@ public class DoublePropertyValidator<DTO>
     // #region - less than or equal to
     // ================================
 
-    public DoublePropertyValidator<DTO> le(double max) {
-        return le(max, String.format("The value should be less than or equal to %s", max));
+    public DoublePropertyValidator<T> le(double max) {
+        return le(max, String.format("The input must be less than or equal to '%s'.", max));
     }
 
-    public DoublePropertyValidator<DTO> le(double max, String errMsg) {
+    public DoublePropertyValidator<T> le(double max, String errMsg) {
         return le(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> le(
+    public <E extends RuntimeException> DoublePropertyValidator<T> le(
             double max, Supplier<E> exceptionCreator) {
         return le(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> DoublePropertyValidator<DTO> le(
+    public <E extends RuntimeException> DoublePropertyValidator<T> le(
             double max, Function<Double, E> exceptionCreator) {
         withRule(value -> (value != null && value <= max), exceptionCreator);
         return this;
@@ -135,7 +135,7 @@ public class DoublePropertyValidator<DTO>
     // ================================
 
     @Override
-    protected DoublePropertyValidator<DTO> thisObject() {
+    protected DoublePropertyValidator<T> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/IntPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/IntPropertyValidator.java
index 4b0d078..431a77e 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/IntPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/IntPropertyValidator.java
@@ -19,10 +19,10 @@ package xyz.zhouxy.plusone.validator;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-public class IntPropertyValidator<DTO>
-        extends BaseComparablePropertyValidator<DTO, Integer, IntPropertyValidator<DTO>> {
+public class IntPropertyValidator<T>
+        extends BaseComparablePropertyValidator<T, Integer, IntPropertyValidator<T>> {
 
-    IntPropertyValidator(Function<DTO, Integer> getter) {
+    IntPropertyValidator(Function<T, Integer> getter) {
         super(getter);
     }
 
@@ -30,20 +30,20 @@ public class IntPropertyValidator<DTO>
     // #region - greater than
     // ================================
 
-    public IntPropertyValidator<DTO> gt(int min) {
-        return gt(min, String.format("The value should be greater than %d", min));
+    public IntPropertyValidator<T> gt(int min) {
+        return gt(min, String.format("The input must be greater than '%d'.", min));
     }
 
-    public IntPropertyValidator<DTO> gt(int min, String errMsg) {
+    public IntPropertyValidator<T> gt(int min, String errMsg) {
         return gt(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> gt(
+    public <E extends RuntimeException> IntPropertyValidator<T> gt(
             int min, Supplier<E> exceptionCreator) {
         return gt(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> gt(
+    public <E extends RuntimeException> IntPropertyValidator<T> gt(
             int min, Function<Integer, E> exceptionCreator) {
         withRule(value -> (value != null && value > min), exceptionCreator);
         return this;
@@ -57,20 +57,20 @@ public class IntPropertyValidator<DTO>
     // #region - greater than or equal to
     // ================================
 
-    public IntPropertyValidator<DTO> ge(int min) {
-        return ge(min, String.format("The value should be greater than or equal to %d", min));
+    public IntPropertyValidator<T> ge(int min) {
+        return ge(min, String.format("The input must be greater than or equal to '%d'.", min));
     }
 
-    public IntPropertyValidator<DTO> ge(int min, String errMsg) {
+    public IntPropertyValidator<T> ge(int min, String errMsg) {
         return ge(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> ge(
+    public <E extends RuntimeException> IntPropertyValidator<T> ge(
             int min, Supplier<E> exceptionCreator) {
         return ge(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> ge(
+    public <E extends RuntimeException> IntPropertyValidator<T> ge(
             int min, Function<Integer, E> exceptionCreator) {
         withRule(value -> (value != null && value >= min), exceptionCreator);
         return this;
@@ -84,20 +84,20 @@ public class IntPropertyValidator<DTO>
     // #region - less than
     // ================================
 
-    public IntPropertyValidator<DTO> lt(int max) {
-        return lt(max, String.format("The value should be less than %d", max));
+    public IntPropertyValidator<T> lt(int max) {
+        return lt(max, String.format("The input must be less than '%d'.", max));
     }
 
-    public IntPropertyValidator<DTO> lt(int max, String errMsg) {
+    public IntPropertyValidator<T> lt(int max, String errMsg) {
         return lt(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> lt(
+    public <E extends RuntimeException> IntPropertyValidator<T> lt(
             int max, Supplier<E> exceptionCreator) {
         return lt(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> lt(
+    public <E extends RuntimeException> IntPropertyValidator<T> lt(
             int max, Function<Integer, E> exceptionCreator) {
         withRule(value -> (value != null && value < max), exceptionCreator);
         return this;
@@ -111,20 +111,20 @@ public class IntPropertyValidator<DTO>
     // #region - less than or equal to
     // ================================
 
-    public IntPropertyValidator<DTO> le(int max) {
-        return le(max, String.format("The value should be less than or equal to %d", max));
+    public IntPropertyValidator<T> le(int max) {
+        return le(max, String.format("The input must be less than or equal to '%d'.", max));
     }
 
-    public IntPropertyValidator<DTO> le(int max, String errMsg) {
+    public IntPropertyValidator<T> le(int max, String errMsg) {
         return le(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> le(
+    public <E extends RuntimeException> IntPropertyValidator<T> le(
             int max, Supplier<E> exceptionCreator) {
         return le(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> IntPropertyValidator<DTO> le(
+    public <E extends RuntimeException> IntPropertyValidator<T> le(
             int max, Function<Integer, E> exceptionCreator) {
         withRule(value -> (value != null && value <= max), exceptionCreator);
         return this;
@@ -135,7 +135,7 @@ public class IntPropertyValidator<DTO>
     // ================================
 
     @Override
-    protected IntPropertyValidator<DTO> thisObject() {
+    protected IntPropertyValidator<T> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/LongPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/LongPropertyValidator.java
index 9c77bbd..776093b 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/LongPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/LongPropertyValidator.java
@@ -19,10 +19,10 @@ package xyz.zhouxy.plusone.validator;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-public class LongPropertyValidator<DTO>
-        extends BaseComparablePropertyValidator<DTO, Long, LongPropertyValidator<DTO>> {
+public class LongPropertyValidator<T>
+        extends BaseComparablePropertyValidator<T, Long, LongPropertyValidator<T>> {
 
-    LongPropertyValidator(Function<DTO, Long> getter) {
+    LongPropertyValidator(Function<T, Long> getter) {
         super(getter);
     }
 
@@ -30,20 +30,20 @@ public class LongPropertyValidator<DTO>
     // #region - greater than
     // ================================
 
-    public LongPropertyValidator<DTO> gt(long min) {
-        return gt(min, String.format("The value should be greater than %d", min));
+    public LongPropertyValidator<T> gt(long min) {
+        return gt(min, String.format("The input must be greater than '%d'.", min));
     }
 
-    public LongPropertyValidator<DTO> gt(long min, String errMsg) {
+    public LongPropertyValidator<T> gt(long min, String errMsg) {
         return gt(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> gt(
+    public <E extends RuntimeException> LongPropertyValidator<T> gt(
             long min, Supplier<E> exceptionCreator) {
         return gt(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> gt(
+    public <E extends RuntimeException> LongPropertyValidator<T> gt(
             long min, Function<Long, E> exceptionCreator) {
         withRule(value -> (value != null && value > min), exceptionCreator);
         return this;
@@ -57,20 +57,20 @@ public class LongPropertyValidator<DTO>
     // #region - greater than or equal to
     // ================================
 
-    public LongPropertyValidator<DTO> ge(long min) {
-        return ge(min, String.format("The value should be greater than or equal to %d", min));
+    public LongPropertyValidator<T> ge(long min) {
+        return ge(min, String.format("The input must be greater than or equal to '%d'.", min));
     }
 
-    public LongPropertyValidator<DTO> ge(long min, String errMsg) {
+    public LongPropertyValidator<T> ge(long min, String errMsg) {
         return ge(min, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> ge(
+    public <E extends RuntimeException> LongPropertyValidator<T> ge(
             long min, Supplier<E> exceptionCreator) {
         return ge(min, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> ge(
+    public <E extends RuntimeException> LongPropertyValidator<T> ge(
             long min, Function<Long, E> exceptionCreator) {
         withRule(value -> (value != null && value >= min), exceptionCreator);
         return this;
@@ -84,20 +84,20 @@ public class LongPropertyValidator<DTO>
     // #region - less than
     // ================================
 
-    public LongPropertyValidator<DTO> lt(long max) {
-        return lt(max, String.format("The value should be less than %d", max));
+    public LongPropertyValidator<T> lt(long max) {
+        return lt(max, String.format("The input must be less than '%d'.", max));
     }
 
-    public LongPropertyValidator<DTO> lt(long max, String errMsg) {
+    public LongPropertyValidator<T> lt(long max, String errMsg) {
         return lt(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> lt(
+    public <E extends RuntimeException> LongPropertyValidator<T> lt(
             long max, Supplier<E> exceptionCreator) {
         return lt(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> lt(
+    public <E extends RuntimeException> LongPropertyValidator<T> lt(
             long max, Function<Long, E> exceptionCreator) {
         withRule(value -> (value != null && value < max), exceptionCreator);
         return this;
@@ -111,20 +111,20 @@ public class LongPropertyValidator<DTO>
     // #region - less than or equal to
     // ================================
 
-    public LongPropertyValidator<DTO> le(long max) {
-        return le(max, String.format("The value should be less than or equal to %d", max));
+    public LongPropertyValidator<T> le(long max) {
+        return le(max, String.format("The input must be less than or equal to '%d'.", max));
     }
 
-    public LongPropertyValidator<DTO> le(long max, String errMsg) {
+    public LongPropertyValidator<T> le(long max, String errMsg) {
         return le(max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> le(
+    public <E extends RuntimeException> LongPropertyValidator<T> le(
             long max, Supplier<E> exceptionCreator) {
         return le(max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> LongPropertyValidator<DTO> le(
+    public <E extends RuntimeException> LongPropertyValidator<T> le(
             long max, Function<Long, E> exceptionCreator) {
         withRule(value -> (value != null && value <= max), exceptionCreator);
         return this;
@@ -135,7 +135,7 @@ public class LongPropertyValidator<DTO>
     // ================================
 
     @Override
-    protected LongPropertyValidator<DTO> thisObject() {
+    protected LongPropertyValidator<T> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ObjectPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ObjectPropertyValidator.java
index 24318b3..29b36c4 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ObjectPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/ObjectPropertyValidator.java
@@ -18,14 +18,15 @@ package xyz.zhouxy.plusone.validator;
 
 import java.util.function.Function;
 
-public class ObjectPropertyValidator<DTO, T> extends BasePropertyValidator<DTO, T, ObjectPropertyValidator<DTO, T>> {
+public class ObjectPropertyValidator<T, TProperty>
+        extends BasePropertyValidator<T, TProperty, ObjectPropertyValidator<T, TProperty>> {
 
-    ObjectPropertyValidator(Function<DTO, T> getter) {
+    ObjectPropertyValidator(Function<T, TProperty> getter) {
         super(getter);
     }
 
     @Override
-    protected ObjectPropertyValidator<DTO, T> thisObject() {
+    protected ObjectPropertyValidator<T, TProperty> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/StringPropertyValidator.java b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/StringPropertyValidator.java
index 6867dec..eaf35b5 100644
--- a/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/StringPropertyValidator.java
+++ b/plusone-validator/src/main/java/xyz/zhouxy/plusone/validator/StringPropertyValidator.java
@@ -36,9 +36,9 @@ import xyz.zhouxy.plusone.commons.util.StringTools;
  *
  * @author <a href="http://zhouxy.xyz:3000/ZhouXY108">ZhouXY</a>
  */
-public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidator<DTO, String, StringPropertyValidator<DTO>> {
+public class StringPropertyValidator<T> extends BaseComparablePropertyValidator<T, String, StringPropertyValidator<T>> {
 
-    StringPropertyValidator(Function<DTO, String> getter) {
+    StringPropertyValidator(Function<T, String> getter) {
         super(getter);
     }
 
@@ -46,17 +46,17 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - matches
     // ================================
 
-    public StringPropertyValidator<DTO> matches(Pattern regex, String errMsg) {
+    public StringPropertyValidator<T> matches(Pattern regex, String errMsg) {
         return matches(regex, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matches(
+    public <E extends RuntimeException> StringPropertyValidator<T> matches(
             Pattern regex,
             Supplier<E> exceptionCreator) {
         return matches(regex, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matches(
+    public <E extends RuntimeException> StringPropertyValidator<T> matches(
             Pattern regex,
             Function<String, E> exceptionCreator) {
         withRule(input -> (input == null || RegexTools.matches(input, regex)), exceptionCreator);
@@ -71,34 +71,34 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - matchesOne
     // ================================
 
-    public StringPropertyValidator<DTO> matchesOne(Pattern[] regexs, String errMsg) {
+    public StringPropertyValidator<T> matchesOne(Pattern[] regexs, String errMsg) {
         return matchesOne(regexs, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesOne(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesOne(
             Pattern[] regexs,
             Supplier<E> exceptionCreator) {
         return matchesOne(regexs, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesOne(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesOne(
             Pattern[] regexs,
             Function<String, E> exceptionCreator) {
         withRule(input -> RegexTools.matchesOne(input, regexs), exceptionCreator);
         return this;
     }
 
-    public StringPropertyValidator<DTO> matchesOne(List<Pattern> regexs, String errMsg) {
+    public StringPropertyValidator<T> matchesOne(List<Pattern> regexs, String errMsg) {
         return matchesOne(regexs, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesOne(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesOne(
             List<Pattern> regexs,
             Supplier<E> exceptionCreator) {
         return matchesOne(regexs, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesOne(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesOne(
             List<Pattern> regexs,
             Function<String, E> exceptionCreator) {
         withRule(input -> input == null || RegexTools.matchesOne(input, regexs.toArray(new Pattern[regexs.size()])), exceptionCreator);
@@ -113,34 +113,34 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - matchesAll
     // ================================
 
-    public StringPropertyValidator<DTO> matchesAll(Pattern[] regexs, String errMsg) {
+    public StringPropertyValidator<T> matchesAll(Pattern[] regexs, String errMsg) {
         return matchesAll(regexs, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesAll(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesAll(
             Pattern[] regexs,
             Supplier<E> exceptionCreator) {
         return matchesAll(regexs, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesAll(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesAll(
             Pattern[] regexs,
             Function<String, E> exceptionCreator) {
         withRule(input -> RegexTools.matchesAll(input, regexs), exceptionCreator);
         return this;
     }
 
-    public StringPropertyValidator<DTO> matchesAll(Collection<Pattern> regexs, String errMsg) {
+    public StringPropertyValidator<T> matchesAll(Collection<Pattern> regexs, String errMsg) {
         return matchesAll(regexs, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesAll(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesAll(
             Collection<Pattern> regexs,
             Supplier<E> exceptionCreator) {
         return matchesAll(regexs, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> matchesAll(
+    public <E extends RuntimeException> StringPropertyValidator<T> matchesAll(
             Collection<Pattern> regexs,
             Function<String, E> exceptionCreator) {
         withRule(input -> input == null || RegexTools.matchesAll(input, regexs.toArray(new Pattern[regexs.size()])), exceptionCreator);
@@ -155,19 +155,19 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - notBlank
     // ================================
 
-    public StringPropertyValidator<DTO> notBlank() {
-        return notBlank("The value must have text; it must not be null, empty, or blank.");
+    public StringPropertyValidator<T> notBlank() {
+        return notBlank("The input must not be blank.");
     }
 
-    public StringPropertyValidator<DTO> notBlank(String errMsg) {
+    public StringPropertyValidator<T> notBlank(String errMsg) {
         return notBlank(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> notBlank(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> StringPropertyValidator<T> notBlank(Supplier<E> exceptionCreator) {
         return notBlank(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> notBlank(
+    public <E extends RuntimeException> StringPropertyValidator<T> notBlank(
             Function<String, E> exceptionCreator) {
         withRule(StringTools::isNotBlank, exceptionCreator);
         return this;
@@ -181,20 +181,20 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - emailAddress
     // ================================
 
-    public StringPropertyValidator<DTO> emailAddress() {
-        return emailAddress("The value is not an email address.");
+    public StringPropertyValidator<T> emailAddress() {
+        return emailAddress("The input is not a valid email address.");
     }
 
-    public StringPropertyValidator<DTO> emailAddress(String errMsg) {
+    public StringPropertyValidator<T> emailAddress(String errMsg) {
         return emailAddress(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> emailAddress(
+    public <E extends RuntimeException> StringPropertyValidator<T> emailAddress(
             Supplier<E> exceptionCreator) {
         return emailAddress(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> emailAddress(
+    public <E extends RuntimeException> StringPropertyValidator<T> emailAddress(
             Function<String, E> exceptionCreator) {
         return matches(PatternConsts.EMAIL, exceptionCreator);
     }
@@ -207,19 +207,19 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - notEmpty
     // ================================
 
-    public StringPropertyValidator<DTO> notEmpty() {
-        return notEmpty("The value must not be empty.");
+    public StringPropertyValidator<T> notEmpty() {
+        return notEmpty("The input must not be empty.");
     }
 
-    public StringPropertyValidator<DTO> notEmpty(String errMsg) {
+    public StringPropertyValidator<T> notEmpty(String errMsg) {
         return notEmpty(convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> notEmpty(Supplier<E> exceptionCreator) {
+    public <E extends RuntimeException> StringPropertyValidator<T> notEmpty(Supplier<E> exceptionCreator) {
         return notEmpty(convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> notEmpty(
+    public <E extends RuntimeException> StringPropertyValidator<T> notEmpty(
             Function<String, E> exceptionCreator) {
         withRule(s -> s != null && !s.isEmpty(), exceptionCreator);
         return this;
@@ -233,19 +233,19 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // #region - length
     // ================================
 
-    public StringPropertyValidator<DTO> length(int length, String errMsg) {
+    public StringPropertyValidator<T> length(int length, String errMsg) {
         return length(length, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> length(int length,
+    public <E extends RuntimeException> StringPropertyValidator<T> length(int length,
             Supplier<E> exceptionCreator) {
         return length(length, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> length(int length,
+    public <E extends RuntimeException> StringPropertyValidator<T> length(int length,
             Function<String, E> exceptionCreator) {
         AssertTools.checkArgument(length >= 0,
-                "The required length must be greater than or equal to 0.");
+                "The expected length must be greater than or equal to 0.");
         withRule(s -> s == null || s.length() == length, exceptionCreator);
         return this;
     }
@@ -258,16 +258,16 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
         return len >= min && len <= max;
     }
 
-    public StringPropertyValidator<DTO> length(int min, int max, String errMsg) {
+    public StringPropertyValidator<T> length(int min, int max, String errMsg) {
         return length(min, max, convertExceptionCreator(errMsg));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> length(int min, int max,
+    public <E extends RuntimeException> StringPropertyValidator<T> length(int min, int max,
             Supplier<E> exceptionCreator) {
         return length(min, max, convertExceptionCreator(exceptionCreator));
     }
 
-    public <E extends RuntimeException> StringPropertyValidator<DTO> length(int min, int max,
+    public <E extends RuntimeException> StringPropertyValidator<T> length(int min, int max,
             Function<String, E> exceptionCreator) {
         AssertTools.checkArgument(min >= 0, "The minimum value must be greater than equal to 0.");
         AssertTools.checkArgument(min < max, "The minimum value must be less than the maximum value.");
@@ -280,7 +280,7 @@ public class StringPropertyValidator<DTO> extends BaseComparablePropertyValidato
     // ================================
 
     @Override
-    protected StringPropertyValidator<DTO> thisObject() {
+    protected StringPropertyValidator<T> thisObject() {
         return this;
     }
 }
diff --git a/plusone-validator/src/test/java/xyz/zhouxy/plusone/example/validator/ObjectPropertyValidatorTests.java b/plusone-validator/src/test/java/xyz/zhouxy/plusone/example/validator/ObjectPropertyValidatorTests.java
index 5405bb9..e7358a3 100644
--- a/plusone-validator/src/test/java/xyz/zhouxy/plusone/example/validator/ObjectPropertyValidatorTests.java
+++ b/plusone-validator/src/test/java/xyz/zhouxy/plusone/example/validator/ObjectPropertyValidatorTests.java
@@ -30,7 +30,6 @@ import com.google.common.collect.Lists;
 
 import xyz.zhouxy.plusone.commons.collection.CollectionTools;
 import xyz.zhouxy.plusone.commons.util.DateTimeTools;
-import xyz.zhouxy.plusone.commons.util.StringTools;
 import xyz.zhouxy.plusone.example.ExampleCommand;
 import xyz.zhouxy.plusone.example.Foo;
 import xyz.zhouxy.plusone.validator.BaseValidator;
diff --git a/pom.xml b/pom.xml
index 84cf435..eea56a2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,7 +18,7 @@
   </modules>
 
   <description>
-    Plusone Validator 是一个参数校验框架，可针对 DTO 创建对应的校验器，并复用该校验器实例，对 DTO 进行校验。
+    Plusone Validator 是一个校验库，用于构建校验规则对对象（尤其是入参）进行校验。API 参考自 .NET 的 FluentValidation。
   </description>
 
   <properties>
@@ -27,6 +27,13 @@
 
   <dependencyManagement>
     <dependencies>
+      <dependency>
+        <groupId>org.junit</groupId>
+        <artifactId>junit-bom</artifactId>
+        <version>5.12.1</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
       <dependency>
         <groupId>xyz.zhouxy.plusone</groupId>
         <artifactId>plusone-dependencies</artifactId>