add methods

hutool-core/src/main/java/cn/hutool/core/stream/StreamUtil.java

@@ -1,7 +1,15 @@
 package cn.hutool.core.stream;
 
 import cn.hutool.core.collection.CollUtil;
+import cn.hutool.core.io.IORuntimeException;
+import cn.hutool.core.lang.Assert;
+import cn.hutool.core.util.CharsetUtil;
 
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.Spliterators;
 import java.util.function.Function;
 import java.util.function.UnaryOperator;
@@ -17,11 +25,9 @@ import java.util.stream.StreamSupport;
 public class StreamUtil {
 
 	@SafeVarargs
-	public static <T> Stream<T> of(T... values) {
-		if (null == values) {
-			return null;
-		}
-		return Stream.of(values);
+	public static <T> Stream<T> of(T... array) {
+		Assert.notNull(array, "Array must be not null!");
+		return Stream.of(array);
 	}
 
 	/**
@@ -44,14 +50,58 @@ public class StreamUtil {
 	 * @return {@link Stream}
 	 */
 	public static <T> Stream<T> of(Iterable<T> iterable, boolean parallel) {
-		if (null == iterable) {
-			return null;
-		}
+		Assert.notNull(iterable, "Iterable must be not null!");
 		return StreamSupport.stream(
 				Spliterators.spliterator(CollUtil.toCollection(iterable), 0),
 				parallel);
 	}
 
+	/**
+	 * 按行读取文件为{@link Stream}
+	 *
+	 * @param file 路径
+	 * @return {@link Stream}
+	 */
+	public static Stream<String> of(File file) {
+		return of(file, CharsetUtil.CHARSET_UTF_8);
+	}
+
+	/**
+	 * 按行读取文件为{@link Stream}
+	 *
+	 * @param path 路径
+	 * @return {@link Stream}
+	 */
+	public static Stream<String> of(Path path) {
+		return of(path, CharsetUtil.CHARSET_UTF_8);
+	}
+
+	/**
+	 * 按行读取文件为{@link Stream}
+	 *
+	 * @param charset 编码
+	 * @return {@link Stream}
+	 */
+	public static Stream<String> of(File file, Charset charset) {
+		Assert.notNull(file, "File must be not null!");
+		return of(file.toPath(), charset);
+	}
+
+	/**
+	 * 按行读取文件为{@link Stream}
+	 *
+	 * @param path    路径
+	 * @param charset 编码
+	 * @return {@link Stream}
+	 */
+	public static Stream<String> of(Path path, Charset charset) {
+		try {
+			return Files.lines(path, charset);
+		} catch (IOException e) {
+			throw new IORuntimeException(e);
+		}
+	}
+
 	/**
 	 * 通过函数创建Stream
 	 *
@@ -68,9 +118,9 @@ public class StreamUtil {
 	/**
 	 * 将Stream中所有元素以指定分隔符，合并为一个字符串，对象默认调用toString方法
 	 *
-	 * @param stream       {@link Stream}
-	 * @param delimiter    分隔符
-	 * @param <T>          元素类型
+	 * @param stream    {@link Stream}
+	 * @param delimiter 分隔符
+	 * @param <T>       元素类型
 	 * @return 字符串
 	 */
 	public static <T> String join(Stream<T> stream, CharSequence delimiter) {