Java Reference
In-Depth Information
The input stream for reading from the binary file
numbers.dat
is opened as follows:
ObjectInputStream inputStream =
new
ObjectInputStream(
new
FileInputStream("numbers.dat"));
Note that this is identical to how we opened a file using
ObjectOutputStream
in
Display 10.13, except that here we have used the classes
ObjectInputStream
and
FileInputStream
instead of
ObjectOutputStream
and
FileOutputStream
.
Opening a Binary File for Reading
Create a stream of the class
ObjectInputStream
and connect it to a binary file as follows:
SYNTAX
ObjectInputStream
Input_Stream_Name
=
new
ObjectInputStream(
new
FileInputStream(
File_Name
));
The constructor for
FileInputStream
may throw a
FileNotFoundException
, which
is a kind of
IOException
. If the
FileInputStream
constructor succeeds, then the
constructor for
ObjectInputStream
may throw a different
IOException
.
EXAMPLES
ObjectInputStream inputFile =
new
ObjectInputStream(
new
FileInputStream("somefile.dat"));
After this, you can use the methods in Display 10.15 to read from the file.
Display 10.15
Some Methods in the Class
ObjectInputStream
(part 1 of 3)
The classes
ObjectInputStream
and
FileInputStream
are in the
java.io
package.
public
ObjectInputStream(InputStream streamObject)
There is no constructor that takes a file name as an argument. If you want to create a stream using
a file name, use
new
ObjectInputStream(
new
FileInputStream(
File_Name
))
Alternatively, you can use an object of the class
File
in place of the
File_Name
, as follows:
new
ObjectInputStream(
new
FileInputStream(
File_Object
))
The constructor for
FileInputStream
may throw a
FileNotFoundException
, which is a
kind of
IOException
. If the
FileInputStream
constructor succeeds, then the constructor for
ObjectInputStream
may throw a different
IOException
.