writing to file with new arrays java -

i need multiplying 2d arrays , input file (input.txt) , need writing multiplied outputs , output file(output.txt) why isn't method shownewarray working?

input.txt:

9 3 8 5  2 3 3 8 2 1 1 2 3 3 5 9  2 2 3 3 4 6 8 9 7 6 

(edit: sorry wrote question fast!)

import java.io.bufferedreader; import java.io.filenotfoundexception; import java.io.filereader; import java.io.filewriter; import java.io.ioexception;  public class hw1 {      public int[][] shownewarray(int[][] matrix1, int[][] matrix2){// mulitplies 2 matrixes         int[][] matrix3 = new int[matrix1.length][matrix2.length];// takes lengths matrix1&&matrix2         for(int =0;i <matrix1.length;i++){             for(int j =0; j<matrix2[0].length;j++){//column length of matrix2                 for(int k =0; k< matrix1[0].length;k++){//column length of matrix1                     matrix3[i][j] += matrix1[i][k] * matrix2[k][j];// multiplies em                 }             }         }         shownewarray(matrix3[][]);     }      public static void main(string args[]){         filereader filereader = null;         filewriter filewriter = null;         bufferedreader bufferedreader = null;         try {             filereader = new filereader("c:/javastuff/principles/input.txt");             filewriter = new filewriter("c:/javastuff/principles/output.txt",true);             bufferedreader = new bufferedreader(filereader);              int flag=0;             string line = null;//initialization             string words[];             int linecount = 0;             int row1=0, column1=0, row2=0, column2=0;             string filedata[] = new string[100];//we assuming file won't contain more 100 lines, drawback             while ((line = bufferedreader.readline()) != null){                  system.out.println(line);//to check code reading file line line                 if(!line.trim().equals("")){//we ignore blank lines                     words = line.trim().split("\\s+"); //split line in words separated spaces                     if(linecount==0){                         row1 = integer.parseint(words[0]);                         column1 = integer.parseint(words[1]);                     }                     else if(linecount==1){                         row2 = integer.parseint(words[0]);                         column2 = integer.parseint(words[1]);                          if(column1!=row2){                             flag = 1;                             break;                         }                      }                     else{                         filedata[linecount] = line;                     }                     linecount++;                 }             }             if(flag==1){                 system.out.println("invalid input.");                 filewriter.write("invalid input.");              }else{                 int[][] matrix1=new int[row1][column1];                 int[][] matrix2=new int[row2][column2];                  int filerow=0;                 for(int index=2;index<row1+2;index++) {                     line = filedata[index];                      if(!line.trim().equals("")){//we ignore blank lines                         words=line.trim().split("\\s+");                         (int col = 0; col < words.length; col++) {                             matrix1[filerow][col] = integer.parseint(words[col]);                         }                         filerow++;                     }                 }                 system.out.println("matrix1:");                 filewriter.write("\nmatrix1:\n");                 for(int p =0;p<row1;p++){                     for(int q =0;q<column1;q++){                         system.out.print(matrix1[p][q]+" ");                         filewriter.write(matrix1[p][q]+" ");                     }                     system.out.println();                     filewriter.write("\n");                 }                 filerow=0;                 for(int index=row1+2;index<row2+row1+2;index++) {                     line = filedata[index];                     if(!line.trim().equals("")){//we ignore blank lines                         words=line.trim().split("\\s+");                         (int col2 = 0; col2 < words.length; col2++) {                             matrix2[filerow][col2] = integer.parseint(words[col2]);                         }                         filerow++;                     }                 }                 system.out.println("matrix2:");                 filewriter.write("\nmatrix2:\n");                  for(int p =0;p<row2;p++){                     for(int q =0;q<column2;q++){                         system.out.print(matrix2[p][q]+" ");                         filewriter.write(matrix2[p][q]+" ");                     }                     system.out.println();                     filewriter.write("\n");                 }             }              bufferedreader.close();             filereader.close();             filewriter.close();          }         catch (numberformatexception e) {             e.printstacktrace();         } catch (filenotfoundexception e) {             e.printstacktrace();         } catch (ioexception e) {             e.printstacktrace();         } catch (exception e) {             e.printstacktrace();         }         shownewarray mpliedtogether = new shownewarray(matrix1[][], matrix2[][]);     } } 

check similar question how write array file java , http://www.java2s.com/tutorial/java/0180__file/usefilewritertowriteanarrayofstringstoafile.htm