弄了个验证用户名长度正则表达式，大家看看有什么问题？ - 黑马程序员技术交流社区

import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class UserReg {
/**
* 验证用户名，支持中英文（包括全角字符）、数字、下划线和减号（全角及汉字算两位）,长度为4-20位,中文按二位计数
* @author www.zuidaima.com
* @param userName
* @return
*/
public static boolean validateUserName(String userName) {
String validateStr = "^[\\w\\-－＿[０-９]\u4e00-\u9fa5\uFF21-\uFF3A\uFF41-\uFF5A]+$";
boolean rs = false;
rs = matcher(validateStr, userName);
if (rs) {
int strLenth = getStrLength(userName);
if (strLenth < 4 || strLenth > 20) {
rs = false;
}
}
return rs;
}
/**
* 获取字符串的长度，对双字符（包括汉字）按两位计数
*
* @param value
* @return
*/
public static int getStrLength(String value) {
int valueLength = 0;
String chinese = "[\u0391-\uFFE5]";
for (int i = 0; i < value.length(); i++) {
String temp = value.substring(i, i + 1);
if (temp.matches(chinese)) {
valueLength += 2;
} else {
valueLength += 1;
}
}
return valueLength;
}
private static boolean matcher(String reg, String string) {
boolean tem = false;
Pattern pattern = Pattern.compile(reg);
Matcher matcher = pattern.matcher(string);
tem = matcher.matches();
return tem;
}
public static void main(String[] args) {
String str = "０－＿ｆ９ｚｄ中22";
String st = "Ａ-ｄｑ_!!！！去符号标号！ノチセたのひちぬ！当然。!!..**半角";
System.out.println(validateUserName(str));
System.out.println(st.replaceAll("[\\pP&&[^-_]]", ""));
System.out.println(st.replaceAll("[\\w\\-一-龥Ａ-Ｚａ-ｚ]", ""));
}
}

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