From 791e0bb85f52ad2c202286c1f3ccab65e04c4349 Mon Sep 17 00:00:00 2001
From: tjh <jinghong.tang@tendcloud.com>
Date: Tue, 22 Feb 2022 15:33:34 +0800
Subject: [PATCH] =?UTF-8?q?=E6=96=B0=E5=A2=9E=EF=BC=9A=E8=8E=B7=E5=8F=96?=
 =?UTF-8?q?=E6=96=87=E4=BB=B6=E8=A1=8C=E6=95=B0FileUtil.getTotalLines?=
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---
 .../main/java/cn/hutool/core/io/FileUtil.java | 42 ++++++++++++-------
 .../java/cn/hutool/core/io/FileUtilTest.java  |  8 ++++
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/io/FileUtil.java b/hutool-core/src/main/java/cn/hutool/core/io/FileUtil.java
index d2fa2a9cc..bb08dfe50 100644
--- a/hutool-core/src/main/java/cn/hutool/core/io/FileUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/io/FileUtil.java
@@ -22,21 +22,7 @@ import cn.hutool.core.util.StrUtil;
 import cn.hutool.core.util.URLUtil;
 import cn.hutool.core.util.ZipUtil;
 
-import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
-import java.io.File;
-import java.io.FileFilter;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.io.PrintWriter;
-import java.io.RandomAccessFile;
-import java.io.Reader;
+import java.io.*;
 import java.net.URI;
 import java.net.URL;
 import java.net.URLConnection;
@@ -567,6 +553,32 @@ public class FileUtil extends PathUtil {
 		}
 	}
 
+	/**
+	 * 计算文件的总行数
+	 *
+	 * @param file 文件
+	 * @return 该文件总行数
+	 */
+	public static int getTotalLines(File file) {
+		if (!isFile(file)) {
+			throw new IORuntimeException("input must be file");
+		}
+
+		try (
+				final BufferedReader reader = getReader(file, CharsetUtil.CHARSET_UTF_8);
+				final LineNumberReader lineNumberReader = new LineNumberReader(reader)
+		) {
+			// 设置起始为1
+			lineNumberReader.setLineNumber(1);
+			// 跳过文件中内容
+			lineNumberReader.skip(Long.MAX_VALUE);
+			// 获取当前行号
+			return lineNumberReader.getLineNumber();
+		} catch (IOException e) {
+			throw new IORuntimeException(e);
+		}
+	}
+
 	/**
 	 * 给定文件或目录的最后修改时间是否晚于给定时间
 	 *
diff --git a/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
index d33cbb29f..d70490e8b 100644
--- a/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
@@ -466,4 +466,12 @@ public class FileUtilTest {
 		Assert.assertTrue(FileUtil.getPrefix(prefixDirTempFile).startsWith("prefix"));
 	}
 
+	@Test
+	@Ignore
+	public void getTotalLinesTest() {
+		// 千万行秒级内返回
+		final int totalLines = FileUtil.getTotalLines(FileUtil.file(""));
+		Assert.assertEquals(10000000, totalLines);
+	}
+
 }