add nullIfBlank

hutool-core/src/main/java/org/dromara/hutool/core/text/CharSequenceUtil.java

@@ -153,6 +153,18 @@ public class CharSequenceUtil extends StrValidator {
 		return isEmpty(str) ? null : str;
 	}
 
+	/**
+	 * 当给定字符串为空字符串时，转换为{@code null}
+	 *
+	 * @param <T> 字符串类型
+	 * @param str 被转换的字符串
+	 * @return 转换后的字符串
+	 * @since 6.0.0
+	 */
+	public static <T extends CharSequence> T nullIfBlank(final T str) {
+		return isBlank(str) ? null : str;
+	}
+
 	/**
 	 * <p>如果给定字符串为{@code null}返回默认值
 	 * <pre>{@code
@@ -4154,7 +4166,7 @@ public class CharSequenceUtil extends StrValidator {
 	 * @param consumer 字符处理
 	 */
 	public static void forEach(final CharSequence str, final Consumer<Character> consumer) {
-		forEach(str, false, (cInt)-> consumer.accept((char) cInt));
+		forEach(str, false, (cInt) -> consumer.accept((char) cInt));
 	}
 
 	/**