How can i improve this function?i need your help....

Question

Hi guys,
i'm a pratical question for you.
I've developed a jas application that reads a txt file and convert it
into an array of byte,fro putting it into a blob field of a db mysql.
With big file i go in heap size memory!
I want to improve my function that makes it,but i'm a bit
inexpert...can you help me?
I have a file so made...
Each line has the same number of value,but i know this number only when
i read the file
string1 string2 string3................
stringx double double......(ever double)
stringy double double......(ever double)
and other lines equals to them from the second.
Only the first line has only strings.
I have read this file using a string array to read the first line and
an arraylist of "Riga" object to read the others lines.....i've used a
vector to store partial data from lines reading and at the end i've
created an array of byte in which i copy the vector.
Can you help me improving my code?
The file has about 50000 rows......so i go in heap memory size...
i know my code isn't too optimized.....can you help me?Please,i'm a
newbie,help me with code if possible...
When i encode the objects i've created into an array of byte i use a
whitespace to separe different value and a ; to separe different lines.
I've done it because in a second moment i've to read the array of byte.
Thanks...this is my code
public class MyBean {
        private UploadedFile myFile;
        private ArrayList rows = new ArrayList();
    private List lines = new ArrayList();
    public MyBean(){
    public List getLines(){
        return lines;
    public void setLines(List lines){
        this.lines=lines;
public boolean insRighe(Riga nuovo){
           return rows.add(nuovo);
    public UploadedFile getMyFile() {
        return myFile;
    public void setMyFile(UploadedFile myFile) {
        this.myFile = myFile;
    public ArrayList getRows() {
                return rows;
        public void setRows(ArrayList rows) {
                this.rows = rows;
    public String carica() throws IOException {
        Riga r;
        Double val[];
        Head h;
        int col=0;
        int row=0;
        byte middlerow=' ';
        byte endrow=';';
        byte[] data=null;
        Vector temp=new Vector();
        int numberOfNumericColumns=0;
        String geneid=null;
        String g=null;
        String[]intest=null;
        BufferedReader br = new BufferedReader(new
InputStreamReader(myFile.getInputStream()));
                String line = null;
        while ((line = br.readLine()) != null) {
                line = line.replace (',', '.');
                StringTokenizer st = new StringTokenizer(line);
                numberOfNumericColumns = (st.countTokens()-1);
                col=(numberOfNumericColumns+1);
            //se siamo nella prima riga(contatore segna 0)
                if(row==0){
                        intest=new String[col];
                        int j=0;
                        while(st.hasMoreTokens()){
                                intest[j]=(st.nextToken().trim());
                                j++;
                        h=new Head(intest);//crei l'oggetto head
                        String []qa=h.getHvalues();
                        String asd="";
                    for(int i=0;i<=qa.length-1;i++){
                        asd=asd.concat(qa[i]+" ");
                    System.out.println("head "+asd);//stampo contenuto
dell' head
                    row=1;
                }//fine if
                else
                        Double[] values=new Double[numberOfNumericColumns];
                    int z=0;
                    geneid=st.nextToken();
                    while (st.hasMoreTokens()) {
                        String app=st.nextToken();
                        values[z]=Double.valueOf(app);
                        z++;
                    r=new Riga(geneid,values); //crei l'oggetto riga
                    System.out.println("riga");
                    System.out.println(r.getgeneid());
                    values=r.getvalues();
                    for(int e=0;e<values.length;e++){
                        System.out.println(values[e]);
                    insRighe(r); //aggiungi
                row++;
                int i = 0;
                while (i < intest.length) {
                        byte[] bytesnew = intest.getBytes();
// temp.addAll(bytesnew);
// memorizza in byte un elemento del vettore alla volta
for (byte b : bytesnew)
temp.add(new Byte(b)); // provare Byte
// temp.addElement(intest[i].getBytes());
temp.addElement(Byte.valueOf(middlerow));
i++;
temp.addElement(Byte.valueOf(endrow));
System.out.println("Intestazione convertita in byte");
for (int l = 0; l < rows.size(); l++) {
r = (Riga) rows.get(l);
g = r.getgeneid();
// temp.addElement(g.getBytes());
byte[] byte2 = g.getBytes();
for (byte c : byte2)
temp.add(new Byte(c));
temp.addElement(Byte.valueOf(middlerow));
val = r.getvalues();
byte[] tempByte1;
for (int e = 0; e <= val.length - 1; e++) {
// Returns a string representation of the double argument.
tempByte1 = Double.toString(val[e]).getBytes();
for (int j = 0; j < tempByte1.length; j++) {
temp.addElement(Byte.valueOf(tempByte1[j]));
temp.addElement(Byte.valueOf(middlerow));
temp.addElement(Byte.valueOf(endrow));
data = new byte[temp.size()];
for (int t = 0; t < temp.size(); t++) {
data[t] = (((Byte) temp.elementAt(t)).byteValue());
return data;
public class Riga{
     private String geneid=null;
     private Double[] values=null;
     public Riga(String idGene,Double[] x ) {
this.geneid=idGene;
this.values=x;
     public String getgeneid(){
          return this.geneid;
     public void setgeneid(String idGene){
          this.geneid=idGene;
     public Double[] getvalues(){
          return this.values;
     public void setvalues(Double[] x){
          this.values=x;
Message was edited by:
giubat

Answer 1

Maybe I didn't understand you, but why are you putting a file with 50000 rows as one single BLOB into a DB? Don't you think it's time for a new table?