修改 apply 方法名为 transformValue；新增 int、long、double 的 checkValue 方法；新增相互转换的方法；XxxRef 全部设为 final 类。

src/main/java/xyz/zhouxy/plusone/commons/base/BoolRef.java

@@ -22,7 +22,7 @@ import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 import xyz.zhouxy.plusone.commons.function.BoolUnaryOperator;
 
 @Beta
-public class BoolRef {
+public final class BoolRef {
 
     private boolean value;
 
@@ -43,10 +43,18 @@ public class BoolRef {
         this.value = value;
     }
 
-    public void apply(BoolUnaryOperator operator) {
+    public void transformValue(BoolUnaryOperator operator) {
         this.value = operator.applyAsBool(this.value);
     }
 
+    public boolean isTrue() {
+        return getValue();
+    }
+
+    public boolean isFalse() {
+        return !value;
+    }
+
     @Override
     public String toString() {
         return String.format("BoolRef[%s]", value);

src/main/java/xyz/zhouxy/plusone/commons/base/ByteRef.java

@@ -22,7 +22,7 @@ import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 import xyz.zhouxy.plusone.commons.function.ByteUnaryOperator;
 
 @Beta
-public class ByteRef {
+public final class ByteRef {
 
     private byte value;
 
@@ -43,7 +43,7 @@ public class ByteRef {
         this.value = value;
     }
 
-    public void apply(ByteUnaryOperator operator) {
+    public void transformValue(ByteUnaryOperator operator) {
         this.value = operator.applyAsByte(this.value);
     }
 

src/main/java/xyz/zhouxy/plusone/commons/base/CharRef.java

@@ -22,7 +22,7 @@ import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 import xyz.zhouxy.plusone.commons.function.CharUnaryOperator;
 
 @Beta
-public class CharRef {
+public final class CharRef {
 
     private char value;
 
@@ -43,7 +43,7 @@ public class CharRef {
         this.value = value;
     }
 
-    public void apply(CharUnaryOperator operator) {
+    public void transformValue(CharUnaryOperator operator) {
         this.value = operator.applyAsChar(this.value);
     }
 

src/main/java/xyz/zhouxy/plusone/commons/base/DoubleRef.java

@@ -16,6 +16,7 @@
 
 package xyz.zhouxy.plusone.commons.base;
 
+import java.util.function.DoublePredicate;
 import java.util.function.DoubleUnaryOperator;
 
 import com.google.common.annotations.Beta;
@@ -23,7 +24,7 @@ import com.google.common.annotations.Beta;
 import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 
 @Beta
-public class DoubleRef {
+public final class DoubleRef {
 
     private double value;
 
@@ -44,10 +45,14 @@ public class DoubleRef {
         this.value = value;
     }
 
-    public void apply(DoubleUnaryOperator operator) {
+    public void transformValue(DoubleUnaryOperator operator) {
         this.value = operator.applyAsDouble(this.value);
     }
 
+    public boolean checkValue(DoublePredicate predicate) {
+        return predicate.test(this.value);
+    }
+
     @Override
     public String toString() {
         return String.format("DoubleRef[%s]", value);

src/main/java/xyz/zhouxy/plusone/commons/base/IntRef.java

@@ -16,6 +16,7 @@
 
 package xyz.zhouxy.plusone.commons.base;
 
+import java.util.function.IntPredicate;
 import java.util.function.IntUnaryOperator;
 
 import com.google.common.annotations.Beta;
@@ -23,7 +24,7 @@ import com.google.common.annotations.Beta;
 import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 
 @Beta
-public class IntRef {
+public final class IntRef {
 
     private int value;
 
@@ -44,10 +45,14 @@ public class IntRef {
         this.value = value;
     }
 
-    public void apply(IntUnaryOperator operator) {
+    public void transformValue(IntUnaryOperator operator) {
         this.value = operator.applyAsInt(this.value);
     }
 
+    public boolean checkValue(IntPredicate predicate) {
+        return predicate.test(this.value);
+    }
+
     @Override
     public String toString() {
         return String.format("IntRef[%s]", value);

src/main/java/xyz/zhouxy/plusone/commons/base/LongRef.java

@@ -16,6 +16,7 @@
 
 package xyz.zhouxy.plusone.commons.base;
 
+import java.util.function.LongPredicate;
 import java.util.function.LongUnaryOperator;
 
 import com.google.common.annotations.Beta;
@@ -23,7 +24,7 @@ import com.google.common.annotations.Beta;
 import xyz.zhouxy.plusone.commons.annotation.StaticFactoryMethod;
 
 @Beta
-public class LongRef {
+public final class LongRef {
 
     private long value;
 
@@ -44,10 +45,14 @@ public class LongRef {
         this.value = value;
     }
 
-    public void apply(LongUnaryOperator operator) {
+    public void transformValue(LongUnaryOperator operator) {
         this.value = operator.applyAsLong(this.value);
     }
 
+    public boolean checkValue(LongPredicate predicate) {
+        return predicate.test(this.value);
+    }
+
     @Override
     public String toString() {
         return String.format("LongRef[%s]", value);

src/main/java/xyz/zhouxy/plusone/commons/base/Ref.java

@@ -18,6 +18,8 @@ package xyz.zhouxy.plusone.commons.base;
 
 import java.util.Objects;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.function.UnaryOperator;
 
 import com.google.common.annotations.Beta;
@@ -55,10 +57,22 @@ public final class Ref<T> {
         this.value = value;
     }
 
-    public void transform(UnaryOperator<T> operator) {
+    public void transformValue(UnaryOperator<T> operator) {
         this.value = operator.apply(this.value);
     }
 
+    public <R> Ref<R> transform(Function<? super T, R> function) {
+        return Ref.of(function.apply(this.value));
+    }
+
+    public boolean checkValue(Predicate<? super T> predicate) {
+        return predicate.test(this.value);
+    }
+
+    public void execute(Consumer<? super T> consumer) {
+        consumer.accept(value);
+    }
+
     public boolean isNull() {
         return this.value == null;
     }
@@ -67,10 +81,44 @@ public final class Ref<T> {
         return this.value != null;
     }
 
-    public void execute(Consumer<? super T> consumer) {
+    // ================================
-        consumer.accept(value);
+    // #region - from
+    // ================================
+
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Boolean> from(BoolRef boolRef) {
+        return new Ref<>(boolRef.getValue());
     }
 
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Byte> from(ByteRef byteRef) {
+        return new Ref<>(byteRef.getValue());
+    }
+
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Character> from(CharRef charRef) {
+        return new Ref<>(charRef.getValue());
+    }
+
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Double> from(DoubleRef doubleRef) {
+        return new Ref<>(doubleRef.getValue());
+    }
+
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Integer> from(IntRef intRef) {
+        return new Ref<>(intRef.getValue());
+    }
+
+    @StaticFactoryMethod(Ref.class)
+    public static Ref<Long> from(LongRef longRef) {
+        return new Ref<>(longRef.getValue());
+    }
+
+    // ================================
+    // #endregion - from
+    // ================================
+
     @Override
     public String toString() {
         return String.format("Ref[%s]", value);

src/test/java/xyz/zhouxy/plusone/commons/util/RefTests.java

@@ -34,9 +34,12 @@ class RefTests {
     @Test
     void testRef() {
         Ref<String> strRef = new Ref<>("ZhouXY");
+        assertTrue(strRef.checkValue("ZhouXY"::equals));
         apply(strRef);
         assertEquals("Hello ZhouXY", strRef.getValue());
         log.info("strRef: {}", strRef);
+
+        assertTrue(strRef.checkValue(str -> str.length() == 12));
     }
 
     void apply(Ref<String> strRef) {
@@ -69,7 +72,7 @@ class RefTests {
     }
 
     void apply(boolean condition, CharRef charRef) {
-        charRef.apply(c -> condition ? '1' : '0');
+        charRef.transformValue(c -> condition ? '1' : '0');
     }
 
     @Test
@@ -81,7 +84,7 @@ class RefTests {
     }
 
     void apply(double num, DoubleRef doubleRef) {
-        doubleRef.apply(d -> d * num);
+        doubleRef.transformValue(d -> d * num);
     }
 
     @Test
@@ -93,7 +96,7 @@ class RefTests {
     }
 
     void apply(int num, IntRef intRef) {
-        intRef.apply(d -> d - num);
+        intRef.transformValue(d -> d - num);
     }
 
     @Test
@@ -105,6 +108,6 @@ class RefTests {
     }
 
     void apply(long num, LongRef longRef) {
-        longRef.apply(d -> d + num);
+        longRef.transformValue(d -> d + num);
     }
 }