Ajuda com Matriz

for(int j=0;j<matriz[i].length;j++){  
                matriz[i][j] = cell[j].getContents(); // linha onde está acusando o erro.  
            }

for(int j=0;j<matriz[i].length;j++){

29/11/2011 08:41:10 org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() for servlet ImportarXls threw exception
java.lang.ArrayIndexOutOfBoundsException: 17
        at Controlador.ImportarXls.processRequest(ImportarXls.java:54)
        at Controlador.ImportarXls.doPost(ImportarXls.java:100)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:662)

try {
           
            Workbook workbook = Workbook.getWorkbook(new File("c:/myfile.xls"));
            Sheet sheet = workbook.getSheet(0); // pega a primeira aba
            Sheet[] abas = workbook.getSheets();


            String[][]matriz = new String [sheet.getRows()][sheet.getColumns()];
            
            //matriz.length -> representa as linhas da matriz
            //matriz[0].length-> pega o tamanho da linha [0], ou seja, pega o numero de colunas
            
            Cell[] cell; // instancia um array de celula que irá auxiliar no povoamento da matriz
            for(int i=0;i<matriz.length;i++){
               cell = sheet.getRow(i);
             //  System.out.println(matriz[i]);
            for(int j=0;j<matriz[i].length ;j++){
            //   System.out.println(cell[j].getContents());
                 matriz[i][j] = cell[j].getContents();
            }

            }

            for(int i=0;i<matriz.length;i++){
                 for(int j=0;j<matriz[i].length;j++){
               System.out.println(matriz[i][j]);
            }
                 System.out.println("");
            }
        } finally { 
            out.close();
        }