From 0390c8c606962eade078de766bfb647d70fb9d90 Mon Sep 17 00:00:00 2001
From: zzzj <jie.jiang@easyview.com.hk>
Date: Thu, 23 Mar 2023 18:04:44 +0800
Subject: [PATCH] =?UTF-8?q?CharSequenceUtil=E6=96=B0=E5=A2=9EcommonPrefix?=
 =?UTF-8?q?=E4=B8=8EcommonSuffix=E6=96=B9=E6=B3=95?=
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---
 .../cn/hutool/core/text/CharSequenceUtil.java | 54 +++++++++++++++++++
 .../core/text/CharSequenceUtilTest.java       | 49 +++++++++++++++++
 2 files changed, 103 insertions(+)

diff --git a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
index 10549f357..107476613 100755
--- a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
@@ -4586,4 +4586,58 @@ public class CharSequenceUtil {
 		return false;
 	}
 
+	/**
+	 *
+	 * @param str1	字符串1
+	 * @param str2	字符串2
+	 * @return	字符串1和字符串2的公共前缀
+	 */
+	public static CharSequence commonPrefix(CharSequence str1, CharSequence str2) {
+
+		if (isBlank(str1) || isBlank(str2)) {
+			return EMPTY;
+		}
+
+		int minLength = Math.min(str1.length(), str2.length());
+
+		int index = 0;
+
+		for (; index < minLength; index++) {
+
+			if (str1.charAt(index) != str2.charAt(index)) {
+				break;
+			}
+
+		}
+
+		return str1.subSequence(0, index);
+	}
+
+	/**
+	 *
+	 * @param str1	字符串1
+	 * @param str2	字符串2
+	 * @return	字符串1和字符串2的公共后缀
+	 */
+	public static CharSequence commonSuffix(CharSequence str1, CharSequence str2) {
+
+		if (isBlank(str1) || isBlank(str2)) {
+			return EMPTY;
+		}
+
+		int str1Index = str1.length() - 1;
+
+		int str2Index = str2.length() - 1;
+
+		for (; str1Index >= 0 && str2Index >= 0; str1Index--, str2Index--) {
+
+			if (str1.charAt(str1Index) != str2.charAt(str2Index)) {
+				break;
+			}
+
+		}
+
+		return str1.subSequence(str1Index + 1, str1.length());
+	}
+
 }
diff --git a/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
index 2672c628b..1962f2ab6 100755
--- a/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
@@ -160,4 +160,53 @@ public class CharSequenceUtilTest {
 		a = null;
 		Assert.assertNull(CharSequenceUtil.trimToNull(a));
 	}
+
+	@Test
+	public void commonPrefixTest() throws Exception{
+
+		// -------------------------- None match -----------------------
+
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix("", "abc"));
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix(null, "abc"));
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix("abc", null));
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix("abc", ""));
+
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix("azzzj", "bzzzj"));
+
+		Assert.assertEquals("", CharSequenceUtil.commonPrefix("english中文", "french中文"));
+
+		// -------------------------- Matched -----------------------
+
+		Assert.assertEquals("name_", CharSequenceUtil.commonPrefix("name_abc", "name_efg"));
+
+		Assert.assertEquals("zzzj", CharSequenceUtil.commonPrefix("zzzja", "zzzjb"));
+
+		Assert.assertEquals("中文", CharSequenceUtil.commonPrefix("中文english", "中文french"));
+
+	}
+
+	@Test
+	public void commonSuffixTest() throws Exception{
+
+		// -------------------------- None match -----------------------
+
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix("", "abc"));
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix(null, "abc"));
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix("abc", null));
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix("abc", ""));
+
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix("zzzja", "zzzjb"));
+
+		Assert.assertEquals("", CharSequenceUtil.commonSuffix("中文english", "中文Korean"));
+
+		// -------------------------- Matched -----------------------
+
+		Assert.assertEquals("_name", CharSequenceUtil.commonSuffix("abc_name", "efg_name"));
+
+		Assert.assertEquals("zzzj", CharSequenceUtil.commonSuffix("abczzzj", "efgzzzj"));
+
+		Assert.assertEquals("中文", CharSequenceUtil.commonSuffix("english中文", "Korean中文"));
+
+	}
+
 }