Java Utililty Methods String Sub String

List of utility methods to do String Sub String

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Description

The list of methods to do String Sub String are organized into topic(s).

Method

Stringsubstring(String src, String fromToken, String toToken)
substring 
int from = src.indexOf(fromToken);
if (from == -1)
    return null;
from += fromToken.length();
int to = src.indexOf(toToken, from);
if (to == -1) {
    return src.substring(from);
return src.substring(from, to);
StringsubString(String src, String start, String to)
Example: subString("abcd","a","c")="b" 
int indexFrom = start == null ? 0 : src.indexOf(start);
int indexTo = to == null ? src.length() : src.indexOf(to);
if (indexFrom < 0 || indexTo < 0 || indexFrom > indexTo) {
    return null;
if (null != start) {
    indexFrom += start.length();
return src.substring(indexFrom, indexTo);
StringsubString(String src, String start, String to)
Example: subString("abcd","a","c")="b" 
int indexFrom = start == null ? 0 : src.indexOf(start);
int indexTo = to == null ? src.length() : src.indexOf(to);
if (indexFrom < 0 || indexTo < 0 || indexFrom > indexTo) {
    return null;
if (null != start) {
    indexFrom += start.length();
return src.substring(indexFrom, indexTo);
StringsubString(String srcStr, int subLen)

Description:Sub a string with the length, 

byte[] bytes = srcStr.getBytes();
if (bytes.length <= subLen)
    return srcStr;
char[] chars = srcStr.toCharArray();
StringBuffer sb = new StringBuffer();
for (int i = 0, j = 0; i < subLen && i < bytes.length && j < chars.length;) {
    char cbyte = (char) bytes[i];
    if (cbyte == chars[j]) {
...
Stringsubstring(String str, char pattern)
substring 
int pos1 = -1, pos2 = -1;
for (int j = 0; j < str.length(); j++) {
    if (str.charAt(j) == pattern) {
        if (pos1 == -1)
            pos1 = j;
        else {
            pos2 = j;
            break;
...
Stringsubstring(String str, int beginIndex)
same as String.substring, except that this version handles the case robustly when the index is out of bounds. 
if (str == null)
    return null;
if (beginIndex < 0)
    return str;
if (beginIndex >= str.length())
    return "";
return str.substring(beginIndex);
StringsubString(String str, int beginIndex, int endIndex)
sub String 
return substring(str, beginIndex, endIndex);
Stringsubstring(String str, int beginIndex, int endIndex)
Index safe substring operation. 
if (beginIndex < 0) {
    beginIndex = 0;
if (endIndex > str.length()) {
    endIndex = str.length();
return str.substring(beginIndex, endIndex);
Stringsubstring(String str, int beginIndex, int endIndex)
substring 
if (str == null)
    return "";
int length = str.length();
endIndex = (endIndex < 0) ? 0 : endIndex;
endIndex = (endIndex > length) ? length : endIndex;
beginIndex = (beginIndex < 0) ? 0 : beginIndex;
beginIndex = (beginIndex > endIndex) ? endIndex : beginIndex;
str = str.substring(beginIndex, endIndex);
...
Stringsubstring(String str, int beginIndex, int len)
substring 
int endIndex = beginIndex + len;
endIndex = endIndex > str.length() ? str.length() : endIndex;
return str.substring(beginIndex, endIndex);