添加注释。

src/main/java/xyz/zhouxy/plusone/commons/function/DoubleToOptionalFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.DoubleFunction;
 
+/**
+ * DoubleToOptionalFunction
+ *
+ * <p>
+ * 接受类型为 double 的参数，返回 {@code Optional&lt;R&gt;} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see DoubleFunction
+ */
 @FunctionalInterface
 public interface DoubleToOptionalFunction<R> extends DoubleFunction<Optional<R>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/IntToOptionalFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.IntFunction;
 
+/**
+ * IntToOptionalFunction
+ *
+ * <p>
+ * 接受类型为 int 的参数，返回 {@code Optional&lt;R&gt;} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see IntFunction
+ */
 @FunctionalInterface
 public interface IntToOptionalFunction<R> extends IntFunction<Optional<R>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/LongToOptionalFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.LongFunction;
 
+/**
+ * LongToOptionalFunction
+ *
+ * <p>
+ * 接受类型为 long 的参数，返回 {@code Optional&lt;R&gt;} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see LongFunction
+ */
 @FunctionalInterface
 public interface LongToOptionalFunction<R> extends LongFunction<Optional<R>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/OptionalDoubleSupplier.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalDouble;
 import java.util.function.Supplier;
 
+/**
+ * OptionalDoubleSupplier
+ *
+ * <p>
+ * 返回 {@link OptionalDouble} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalDouble
+ * @see Supplier
+ */
 @FunctionalInterface
 public interface OptionalDoubleSupplier extends Supplier<OptionalDouble> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/OptionalIntSupplier.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalInt;
 import java.util.function.Supplier;
 
+/**
+ * OptionalIntSupplier
+ *
+ * <p>
+ * 返回 {@link OptionalInt} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalInt
+ * @see Supplier
+ */
 @FunctionalInterface
 public interface OptionalIntSupplier extends Supplier<OptionalInt> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/OptionalLongSupplier.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalLong;
 import java.util.function.Supplier;
 
+/**
+ * OptionalLongSupplier
+ *
+ * <p>
+ * 返回 {@link OptionalLong} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalLong
+ * @see Supplier
+ */
 @FunctionalInterface
 public interface OptionalLongSupplier extends Supplier<OptionalLong> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/OptionalSupplier.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.Supplier;
 
+/**
+ * OptionalSupplier
+ *
+ * <p>
+ * 返回 {@code Optional&lt;T&gt;} 对象。
+ * 
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see Supplier
+ */
 @FunctionalInterface
 public interface OptionalSupplier<T> extends Supplier<Optional<T>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/Predicates.java

@@ -1,9 +1,51 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.function.Predicate;
 
+/**
+ * Predicates
+ *
+ * <p>
+ * {@link Predicate} 相关操作。
+ * </p>
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Predicate
+ */
 public class Predicates {
 
+    /**
+     * 将 lambda 表达式或者方法引用指明为对应类型的 {@link Predicate} 对象。
+     * 如将 {@code Objects::nonNull} 明确地指定为 {@code Predicate&lt;String&gt;}，
+     * 使之可以链式调用 {@link Predicate#and(Predicate)}、{@link Predicate#or(Predicate)}
+     * 等方法，连接其它 {@code Predicate<? super String>} 对象。
+     * 
+     * <pre>
+     * Predicate&lt;String&gt; predicate = Predicates.&lt;String&gt;of(Objects::nonNull)
+     *         .and(StringUtils::isNotEmpty);
+     * </pre>
+     * 
+     * @param <T>
+     * @param predicate
+     * @return
+     */
     public static <T> Predicate<T> of(Predicate<? super T> predicate) {
         return predicate::test;
     }

src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalBiFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.BiFunction;
 
+/**
+ * ToOptionalBiFunction
+ *
+ * <p>
+ * 接受类型为 T 和 U 的两个参数，返回 {@code Optional&lt;R&gt;} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see BiFunction
+ */
 @FunctionalInterface
 public interface ToOptionalBiFunction<T, U, R> extends BiFunction<T, U, Optional<R>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalDoubleFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalDouble;
 import java.util.function.Function;
 
+/**
+ * ToOptionalDoubleFunction
+ *
+ * <p>
+ * 接受类型为 T 的参数，返回 {@link OptionalDouble} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalDouble
+ * @see Function
+ */
 @FunctionalInterface
 public interface ToOptionalDoubleFunction<T> extends Function<T, OptionalDouble> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.Optional;
 import java.util.function.Function;
 
+/**
+ * ToOptionalFunction
+ *
+ * <p>
+ * 接受类型为 T 的参数，返回 {@code Optional&lt;R&gt;} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see Optional
+ * @see Function
+ */
 @FunctionalInterface
 public interface ToOptionalFunction<T, R> extends Function<T, Optional<R>> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalIntFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalInt;
 import java.util.function.Function;
 
+/**
+ * ToOptionalIntFunction
+ *
+ * <p>
+ * 接受类型为 T 的参数，返回 {@link OptionalInt} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalInt
+ * @see Function
+ */
 @FunctionalInterface
 public interface ToOptionalIntFunction<T> extends Function<T, OptionalInt> {
 }

src/main/java/xyz/zhouxy/plusone/commons/function/ToOptionalLongFunction.java

@@ -1,8 +1,35 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package xyz.zhouxy.plusone.commons.function;
 
 import java.util.OptionalLong;
 import java.util.function.Function;
 
+/**
+ * ToOptionalLongFunction
+ *
+ * <p>
+ * 接受类型为 T 的参数，返回 {@link OptionalLong} 对象。
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @since 0.1.0
+ * @see OptionalLong
+ * @see Function
+ */
 @FunctionalInterface
 public interface ToOptionalLongFunction<T> extends Function<T, OptionalLong> {
 }