java - 起始序列的正则表达式

Question

package xmlchars;

import java.util.regex.Pattern;

public class TestRegex {

public static final String SPECIAL_CHARACTERS = "(?i)^[^a-z_]|[^a-z0-9-_.]";


public static void main(String[] args) {
    // TODO Auto-generated method stub
    String name = "#1998St #";  
    Pattern pattern = Pattern.compile(SPECIAL_CHARACTERS);      
    System.out.println(pattern.matcher(name).replaceAll(""));//gives wrong output 1998St            
}

}

基本上我想要实现的是

1. 仅以 a-z 和 _ 开头的字符串
2. 包含 a-z 0-9 _ - 的字符串。开始后
3. 整个字符串不区分大小写

Answer 1

你可以说:

... SPECIAL_CHARACTERS = "^[a-z_][a-z0-9_]+$";

并通过以下方式定义模式:

Pattern pattern = Pattern.compile(SPECIAL_CHARACTERS, Pattern.CASE_INSENSITIVE);