Java Reference
In-Depth Information
Self-Test Exercises
32. Write code to open the binary file named
someStuff
and connect it to an
ObjectInputStream
object named
inputThing
so it is ready for reading.
33. Give a statement that will read a number of type
double
from the file
someStuff
and place the value in a variable named
number
. Use the stream
inputThing
that
you created in Self-Test Exercise 32. (Assume the first thing written to the file
was written using the method
writeDouble
of the class
ObjectOutputStream
and
assume
number
is of type
double
.)
34. Give a statement that will close the stream
inputThing
created in Self-Test
Exercise 32.
35. Can one program write a number to a file using
writeInt
and then have another
program read that number using
readLong
? Can a program read that number
using
readDouble
?
36. Can you use
readUTF
to read a string from a text file?
Display 10.16
Reading from a Binary File
(part 1 of 2)
1
import
java.io.ObjectInputStream;
2
import
java.io.FileInputStream;
3
import
java.io.IOException;
4
import
java.io.FileNotFoundException;
5
public
class
BinaryInputDemo
6{
7
public
static
void
main(String[] args)
8 {
9
try
10
{
11
ObjectInputStream inputStream =
12
new
ObjectInputStream(
new
FileInputStream("numbers.dat"));
13
System.out.println("Reading the file numbers.dat.");
14
int
n1 = inputStream.readInt();
15
int
n2 = inputStream.readInt();
16
System.out.println("Numbers read from file:");
17
System.out.println(n1);
18
System.out.println(n2);
19
inputStream.close();
20
}