如何在java中为匹配字符串和BigIntger编写正则表达式？

Question

我试着用这个网站https://www . free formatter . com/Java-regex-tester . html # ad-output。但是我没有成功。

我的Java正则表达式：

(.*)\\w+=[0-9][0-9]*$(.*)

要测试的条目：

a = 800000000000000000000000

我的代码需要为< code>data.matches(()提供< code>true。*)\\w =[0-9][0-9]*$(。*)" " ，共< code >个

Answer 1

扩展之前的回答和atmin的评论(我还不能在任何地方发表评论)，你可以用以下方式排除前导零:

String regex = "0|(\\-?[1-9]\\d*)";
String stringToTest = "..."
boolean result = stringToTest.matches(regex);

Answer 2

按如下方式执行：

public class Main {
    public static void main(String[] args) {
        String[] testStrs = { "a = 800000000000000000000000", "a = ABC800000000000000000000000",
                "a = 800000000000000000000000ABC", "a = 12.45", "a = 800000000000ABC000000000000", "a = ABC",
                "a = 900000000000000000000000", "a = -800000000000000000000000", "a = -900000000000000000000000" };
        for (String str : testStrs) {
            System.out.println(
                    str + " -> " + (str.matches("[A-Za-z]\\s+=\\s+[-]?\\d+") ? " matches." : " does not match."));
        }
    }
}

输出：

a = 800000000000000000000000 ->  matches.
a = ABC800000000000000000000000 ->  does not match.
a = 800000000000000000000000ABC ->  does not match.
a = 12.45 ->  does not match.
a = 800000000000ABC000000000000 ->  does not match.
a = ABC ->  does not match.
a = 900000000000000000000000 ->  matches.
a = -800000000000000000000000 ->  matches.
a = -900000000000000000000000 ->  matches.

解释：

1. [A-Za-z]代表字母
2. \\s表示空间
3. [-]? 是可选的-
4. \\d代表数字