diff --git a/hutool-core/src/main/java/cn/hutool/core/io/NioUtil.java b/hutool-core/src/main/java/cn/hutool/core/io/NioUtil.java
index b584444c6..bece2b04f 100644
--- a/hutool-core/src/main/java/cn/hutool/core/io/NioUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/io/NioUtil.java
@@ -74,7 +74,9 @@ public class NioUtil {
 	public static long copyByNIO(final InputStream in, final OutputStream out, final int bufferSize, final long count, final StreamProgress streamProgress) throws IORuntimeException {
 		Assert.notNull(in, "InputStream channel is null!");
 		Assert.notNull(out, "OutputStream channel is null!");
-		return copy(Channels.newChannel(in), Channels.newChannel(out), bufferSize, count, streamProgress);
+		final long copySize = copy(Channels.newChannel(in), Channels.newChannel(out), bufferSize, count, streamProgress);
+		IoUtil.flush(out);
+		return copySize;
 	}
 
 	/**
diff --git a/hutool-core/src/main/java/cn/hutool/core/io/copy/ChannelCopier.java b/hutool-core/src/main/java/cn/hutool/core/io/copy/ChannelCopier.java
index 1909e9943..e3e25823b 100755
--- a/hutool-core/src/main/java/cn/hutool/core/io/copy/ChannelCopier.java
+++ b/hutool-core/src/main/java/cn/hutool/core/io/copy/ChannelCopier.java
@@ -103,7 +103,8 @@ public class ChannelCopier extends IoCopier<ReadableByteChannel, WritableByteCha
 			numToRead -= read;
 			total += read;
 			if (null != progress) {
-				progress.progress(this.count, total);
+				// 总长度未知的情况下，-1表示未知
+				progress.progress(this.count < Long.MAX_VALUE ? this.count : -1, total);
 			}
 		}
 
diff --git a/hutool-core/src/test/java/cn/hutool/core/io/NioUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/io/NioUtilTest.java
index b1d9f4d3e..334d76212 100755
--- a/hutool-core/src/test/java/cn/hutool/core/io/NioUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/io/NioUtilTest.java
@@ -2,20 +2,55 @@ package cn.hutool.core.io;
 
 import cn.hutool.core.io.resource.ResourceUtil;
 import cn.hutool.core.io.stream.EmptyOutputStream;
+import cn.hutool.core.lang.Console;
 import cn.hutool.core.text.StrUtil;
 import org.junit.Assert;
+import org.junit.Ignore;
 import org.junit.Test;
 
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.File;
 import java.io.IOException;
 import java.nio.channels.FileChannel;
 
 public class NioUtilTest {
 	@Test
 	public void copyByNIOTest() {
+		final File file = FileUtil.file("hutool.jpg");
 		final long size = NioUtil.copyByNIO(ResourceUtil.getStream("hutool.jpg"), EmptyOutputStream.INSTANCE, NioUtil.DEFAULT_MIDDLE_BUFFER_SIZE, null);
+
+		// 确认写出
+		Assert.assertEquals(file.length(), size);
 		Assert.assertEquals(22807, size);
 	}
 
+	@Test
+	@Ignore
+	public void copyByNIOTest2() throws IOException {
+		final File file = FileUtil.file("d:/test/logo.jpg");
+		final BufferedInputStream in = FileUtil.getInputStream(file);
+		final BufferedOutputStream out = FileUtil.getOutputStream("d:/test/2logo.jpg");
+
+		final long copySize = IoUtil.copyByNIO(in, out, NioUtil.DEFAULT_BUFFER_SIZE, new StreamProgress() {
+			@Override
+			public void start() {
+				Console.log("start");
+			}
+
+			@Override
+			public void progress(final long total, final long progressSize) {
+				Console.log("{} {}", total, progressSize);
+			}
+
+			@Override
+			public void finish() {
+				Console.log("finish");
+			}
+		});
+		Assert.assertEquals(file.length(), copySize);
+	}
+
 	@Test
 	public void readUtf8Test() throws IOException {
 		final String s = NioUtil.readUtf8(FileChannel.open(FileUtil.file("text.txt").toPath()));
diff --git a/hutool-http/src/main/resources/META-INF/services/cn.hutool.http.client.ClientEngine b/hutool-http/src/main/resources/META-INF/services/cn.hutool.http.client.ClientEngine
deleted file mode 100755
index a735c86ec..000000000
--- a/hutool-http/src/main/resources/META-INF/services/cn.hutool.http.client.ClientEngine
+++ /dev/null
@@ -1,3 +0,0 @@
-cn.hutool.http.client.engine.httpclient5.HttpClient5Engine
-cn.hutool.http.client.engine.httpclient4.HttpClient4Engine
-cn.hutool.http.client.engine.okhttp.OkHttpEngine