1.
public static void main(String[] args) { System.out.println(getEmailSuffix("[email protected]")); // 163.com System.out.println(getEmailSuffix("@qq.com")); //qq.com } private static String getEmailSuffix(String email) { email = defaultIfBlank(email,"").trim(); if (!email.isEmpty()) { int index = email.indexOf(‘@‘) + 1; if (index < email.length()) { return email.substring(index).toLowerCase(); } } return ""; } public static <T extends CharSequence> T defaultIfBlank(final T str, final T defaultStr) { return isBlank(str) ? defaultStr : str; } public static boolean isBlank(final CharSequence cs) { int strLen; if (cs == null || (strLen = cs.length()) == 0) { return true; } for (int i = 0; i < strLen; i++) { if (!Character.isWhitespace(cs.charAt(i))) { return false; } } return true; } }
2. 优化,封装到一个公用的字符串操作类中去
public static String getEmailSuffix(String email) { email = MyStringUtils.defaultIfBlank(email,"").trim(); if (!email.isEmpty()) { int index = email.indexOf(‘@‘) + 1; if (index < email.length()) { return email.substring(index).toLowerCase(); } } return ""; } //自己封装的字符串操作类 class MyStringUtils { public static <T extends CharSequence> T defaultIfBlank(final T str, final T defaultStr) { return isBlank(str) ? defaultStr : str; } public static boolean isBlank(final CharSequence cs) { int strLen; if (cs == null || (strLen = cs.length()) == 0) { return true; } for (int i = 0; i < strLen; i++) { if (!Character.isWhitespace(cs.charAt(i))) { return false; } } return true; } public static boolean isNotBlank(final CharSequence cs) { return !isBlank(cs); } public static String defaultString(Object obj) { return obj == null ? "" : obj.toString(); } }
时间: 2024-10-03 00:35:17