Re: write read string data
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bH schreef:
Hi All,
I am attempting to write data into a file and read it
back again.
The error occurs with reading the data file back,
or so it would appear as the current output of that
data is merely a column of null.
import java.io.*;
public class Example4withIO {
String[][] tmp_array = new String [5][5] ;
public static void main(String[] args) {
new Example4withIO();
}
public Example4withIO() {
// final String[] names = {"First Name",
// "Last Name", "Favorite Color",
// "Favorite Number", "Vegetarian"};
final Object[][] data = {
{"Mark", "Andrews", "Red", new Integer(2),
Boolean.TRUE},
{"Tom", "Ball", "Blue", new Integer(99),
Boolean.FALSE},
{"Alan", "Chung", "Green", new Integer(838),
Boolean.FALSE},
{"Jeff", "Dinkins", "Turquois", new Integer(8),
Boolean.TRUE},
{"Amy", "Fowler", "Yellow", new Integer(3),
Boolean.FALSE},
};
In a more advanced application, you would create a class Person which
has these things as attributes, but I understand that this is only an
exercise.
try {
FileOutputStream f_out = new FileOutputStream
("C:\\myarray.data");
ObjectOutputStream obj_out =
new ObjectOutputStream (f_out);
Java naming conventions[1] would require you to write that as fOut,
objOut. Also, consider using more descriptive names.
obj_out.writeObject(data);
obj_out.flush();
obj_out.close();
}
catch (IOException e)
{
System.out.println("error obj_out");
You might want to e.printStackTrace().
}
// end saving data
// attempting to recover the data
try {
BufferedReader obj_in =
new BufferedReader(new FileReader
("C:\\myarray.data"));
tmp_array.equals (obj_in);
obj_in.close();
You never actually read from the BufferedReader. equals is just a
method to compare objects, see the Javadoc[2].
What you need is ObjectInputStream[3] and its readObject() method.
HTH, H.
[1] http://java.sun.com/docs/codeconv/html/CodeConventions.doc8.html
[2]
<http://72.5.124.55/javase/6/docs/api/java/lang/Object.html#equals(java.l=
ang.Object)>
[3] http://72.5.124.55/javase/6/docs/api/java/io/ObjectInputStream.html
--
Hendrik Maryns
http://tcl.sfs.uni-tuebingen.de/~hendrik/
==================
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