support x,y for sm2

hutool-core/src/main/java/cn/hutool/core/util/HexUtil.java

@@ -1,6 +1,7 @@
 package cn.hutool.core.util;
 
 import java.awt.Color;
+import java.math.BigInteger;
 import java.nio.charset.Charset;
 
 /**
@@ -198,6 +199,7 @@ public class HexUtil {
 		if (StrUtil.isEmpty(hexStr)) {
 			return null;
 		}
+		hexStr = StrUtil.removeAll(hexStr, ' ');
 		return decodeHex(hexStr.toCharArray());
 	}
 
@@ -338,6 +340,19 @@ public class HexUtil {
 		builder.append(toDigits[low]);
 	}
 
+	/**
+	 * Hex（16进制）字符串转为BigInteger
+	 * @param hexStr Hex(16进制字符串)
+	 * @return {@link BigInteger}
+	 * @since 5.2.0
+	 */
+	public static BigInteger toBigInteger(String hexStr){
+		if(null == hexStr){
+			return null;
+		}
+		return new BigInteger(hexStr, 16);
+	}
+
 	// ---------------------------------------------------------------------------------------- Private method start
 
 	/**

hutool-core/src/test/java/cn/hutool/core/util/HexUtilTest.java

@@ -38,4 +38,11 @@ public class HexUtilTest {
 		boolean isHex = HexUtil.isHexNumber(a);
 		Assert.assertTrue(isHex);
 	}
+
+	@Test
+	public void decodeTest(){
+		String str = "e8c670380cb220095268f40221fc748fa6ac39d6e930e63c30da68bad97f885d";
+		Assert.assertArrayEquals(HexUtil.decodeHex(str),
+				HexUtil.decodeHex(str.toUpperCase()));
+	}
 }