java应用substring()函数删除指定字符串方法

java应用substring()函数删除指定字符串方法
public class main {

/**
* case insensitive removal of a substring if it is at the end of a source string,
* otherwise returns the source string.
*
* a <code>null</code> source string will return <code>null</code>.
* an empty ("") source string will return the empty string.
* a <code>null</code> search string will return the source string.
*
* <pre>
* stringutils.removeend(null, *) = null
* stringutils.removeend("", *) = ""
* stringutils.removeend(*, null) = *
* stringutils.removeend("www.domain.com", ".com.") = "www.domain.com."
* stringutils.removeend("www.domain.com", ".com") = "www.domain"
* stringutils.removeend("www.domain.com", "domain") = "www.domain.com"
* stringutils.removeend("abc", "") = "abc"
* </pre>
*
* @param str the source string to search, may be null
* @param remove the string to search for (case insensitive) and remove, may be null
* @return the substring with the string removed if found,
* <code>null</code> if null string input
* @since 2.4
*/
public static string removeendignorecase(string str, string remove) {
if (isempty(str)www.3ppt.com || isempty(remove)) {
return str;
}
if (endswithignorecase(str, remove)) {
return str.substring(0, str.length() - remove.length());
}
return str;
}
/**
* case insensitive check if a string ends with a specified suffix.
*
* <code>null</code>s are handled without exceptions. two <code>null</code>
* references are considered to be equal. the comparison is case insensitive.
*
* <pre>
* stringutils.endswithignorecase(null, null) = true
* stringutils.endswithignorecase(null, "abcdef") = false
* stringutils.endswithignorecase("def", null) = false
* stringutils.endswithignorecase("def", "abcdef") = true
* stringutils.endswithignorecase("def", "abcdef") = false
* </pre>
*
* @see java.lang.string#endswith(string)
* @param str the string to check, may be null
* @param suffix the suffix to find, may be null
* @return <code>true</code> if the string ends with the suffix, case insensitive, or
* both <code>null</code>
* @since 2.4
*/
public static boolean endswithignorecase(string str, string suffix) {
return endswith(str, suffix, true);
}

/**
* check if a string ends with a specified suffix (optionally case insensitive).
*
* @see java.lang.string#endswith(string)
* @param str the string to check, may be null
* @param suffix the suffix to find, may be null
* @param ignorecase inidicates whether the compare should ignore case
* (case insensitive) or not.
* @return <code>true</code> if the string starts with the prefix or
* both <code>null</code>
*/
private static boolean endswith(string str, string suffix, boolean ignorecase) {
if (str == null || suffix == null) {
return (str == null && suffix == null);
}
if (suffix.length() > str.length()) {
return false;
}
int stroffset = str.length() - suffix.length();
return str.regionmatches(ignorecase, stroffset, suffix, 0, suffix.length());
}
// empty checks
//-----------------------------------------------------------------------
/**
* checks if a string is empty ("") or null.
*
* <pre>
* stringutils.isempty(null) = true
* stringutils.isempty("") = true
* stringutils.isempty(" ") = false
* stringutils.isempty("bob") = false
* stringutils.isempty(" bob ") = false
* </pre>
*
* note: this method changed in lang version 2.0.
* it no longer trims the string.
* that functionality is available in isblank().
*
* @param str the string to check, may be null
* @return <code>true</code> if the string is empty or null
*/
public static boolean isempty(string str) {
return str == null || str.length() == 0;
}
}