java - Searching for chars from a String in a 2d char array? -

i want able search through array , find chars in string user has input? if user types "message" want return index of 'm' 'e' 's' , on. how this? heres code far:

import java.util.arraylist; import java.util.scanner;  public class matrix { private char[][] matrix = new char[6][6]; private int[] usednumbers = new int[50];  {for(int x = 0; x < usednumbers.length; x++) usednumbers[x] = -1;}  private final char[] cipher_key = {'a','d','f','g','v','x'}; private final string validchars = "abcdefghijklmnopqrstuvwxyz0123456789";   public matrix() {     int random;     for(int = 0; < cipher_key.length; i++) {         for(int j = 0; j < cipher_key.length; j++) {             validation: while(true) {                 random = (int)(math.random()*validchars.length()-1);                 for(int k = 0; k < usednumbers.length; k++) {                     if(random == usednumbers[k]) continue validation;                     else if(usednumbers[k]==-1) usednumbers[k] = random;                 }                 break;             }             matrix[i][j] = validchars.split("")[random].charat(0);           }     } }  public void searchmatrix(){      scanner console = new scanner (system.in);      string phrase = "";      system.out.println("\n enter message "             + "to encrypt cipher: \n");     phrase = console.nextline();      char[] phrasesplit = phrase.tochararray();      console.close();  }  public string tostring() {     string output = "   d f g v x\n";     for(int = 0; < cipher_key.length; i++) {         output += cipher_key[i] + "  ";         for(int j = 0; j < cipher_key.length; j++) {             output += matrix[i][j] + " ";         }         output += "\n";     }     return output; }// tostring end  } 

i have looked tutorials online cant find 1 me in situation! help? dont know next.

if not mistaking, there. have add nested loops after got phrasesplit.

for (int k=0; k<phrasesplit.length; k++) {     (int i=0; i<matrix.length; i++) {         (int j=0; j<matrix[i].length; j++) {             if (phrasesplit[k] == matrix[i][j]) {                 system.out.printf("%c @ %d, %d\n", phrasesplit[k], i, j);             }//end if         }//end j     }//end }//end k 

there may better way it. also, sasha's shuffle() suggestion.