java - generate longest possible palindrome for a given string -

i've been trying generate longest possible palindrome included in given string, in java. but, ended in errors.

let me provide sample input , output may .

input: this sample string testing

output: ttissaepeassitt

it great if solve me this!!

thank you!!

you use recursive algorithm:

public string findpalindrom(string input){    string palindrom = "";    for(int i=0; i<input.length(); i++){       char c = input.charat(i); // explore string beginning, char char       for(int j=input.length()-1; j>i; j--){ // explore string end, char char          if(input.charat(j)==c){ // found letter palindrom             string newpalindrom = c + findpalindrom(input.substring(i+1, j)) + c;             if(newpalindrom.length() > palindrom.length())                palindrom = newpalindrom;          }       }    }    if(palindrom.length()==0 && input.length()>0)       palindrom += input.charat(0); // manage case palindrom possible single char.    return palindrom; }