kalpana
Posts: 2
Nickname: kalpana
Registered: Feb, 2002
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slow painting while reading and writing doubles for MB Files
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Posted: Mar 18, 2002 9:52 PM
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for 15MB length file i = 7662080
for 50MB length file i = 12414368
Part of Code for writing into file follows like this:
----------------------------------------------------
try{
fos = new FileOutputStream("Angel.txt");
File f = new File("Angel.txt");
if(f.length() >=4)
{
f.delete();
fos = new FileOutputStream("Angel.txt");
}
dos = new DataOutputStream(new BufferedOutputStream(fos,1000000));
int x=0;
double y_last, y_new;
for(int j=0 ;j<i ;j++)
{
---
---
---
if(some condition)
{
y_new = ....;
try{
//previously in vectors
y_last = y_new;
vect.add(new Line2D.Double(x, y_last, x, y_new)_;
dos.writeDouble(y_new);
}catch(Exception e){System.out.println(e);}
}
}
dos.close();
fos.close();
x++;
}catch(Exception excp){System.out.println(excp);}
part of code for reading from file follows like this:
-----------------------------------------------------
public void paint(Graphics g)
{
try{
double y1, y2 =0;
Line2D.Double doub;
raf = new RandomAccessFile("Angel.txt","r");
dis = new DataInputStream(new BufferedInputStream(new FileInputStream(raf.getFD(),1000000)));
raf.seek((rect.x*8));
for (int i = rect.x; (i < (rect.x + rect.width)); i++)
{
g2.setStroke(new BasicStroke(0)); //2
y1 = y2;
y2 =dis.readDouble();
doub=new Line2D.Double(i,y1,i,y2);
g2.draw(doub);
}
dis.close();
raf.close();
}catch(Exception excp){System.out.println(excp);}
}
I tried using Object Streams but NotSerializable Exception is thrown as Line2D.Double objects
are not serialized.
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