java 判断字符串是否是数字

2026-05-14

java #code

方法1: Using `Integer.parseInt` or `Double.parseDouble`

public class NumberUtils {
    public static boolean isNumeric(String str) {
        if (str == null || str.isEmpty()) {
            return false;
        }
        try {
            Double.parseDouble(str);
            return true;
        } catch (NumberFormatException e) {
            return false;
        }
    }
}

方法2: Using Regular Expressions

public class NumberUtils {
    public static boolean isNumeric(String str) {
        if (str == null || str.isEmpty()) {
            return false;
        }
        return str.matches("-?\\d+(\\.\\d+)?");
    }
}

方法3: Using `Character` Class

public class NumberUtils {
    public static boolean isNumeric(String str) {
        if (str == null || str.isEmpty()) {
            return false;
        }
        for (char c : str.toCharArray()) {
            if (!Character.isDigit(c)) {
                return false;
            }
        }
        return true;
    }
}