BINARY I/O - Introduction to Java Programming: Comprehensive Version - page 689

java.io.OutputStream

java.io.FilterOutputStream

java.io.BufferedOutputStream

+BufferedOutputStream(out: OutputStream) Creates a BufferedOutputStream from an

OutputStream object.
Creates a BufferedOutputStream from an
OutputStream object with specified size.

+BufferedOutputStream(out: OutputStream, bufferSize: int)

F IGURE 17.14

BufferedOutputStream buffers an output stream.

If no buffer size is specified, the default size is 512 bytes. You can improve the perfor-
mance of the TestDataStream program in Listing 17.2 by adding buffers in the stream in
lines 6-7 and lines 19-20, as follows:

DataOutputStream output = new DataOutputStream(
new BufferedOutputStream( new FileOutputStream( "temp.dat" )));

DataInputStream input = new DataInputStream(
new BufferedInputStream( new FileInputStream( "temp.dat" )));

Tip
You should always use buffered I/O to speed up input and output. For small files, you
may not notice performance improvements. However, for large files—over 100 MB—
you will see substantial improvements using buffered I/O.
17.8 Why do you have to declare to throw IOException in the method or use a try-catch
block to handle IOException for Java I/O programs?
17.9 Why should you always close streams? How do you close streams?
17.10 The read() method in InputStream reads a byte. Why does it return an int
instead of a byte ? Find the abstract methods in InputStream and OutputStream .
17.11 Does FileInputStream / FileOutputStream introduce any new methods beyond
the methods inherited from InputStream / OutputStream ? How do you create a
FileInputStream / FileOutputStream ?

✓ ✓

Check

Point

17.12

What will happen if you attempt to create an input stream on a nonexistent file? What
will happen if you attempt to create an output stream on an existing file? Can you
append data to an existing file?

17.13

How do you append data to an existing text file using java.io.PrintWriter ?

17.14

Suppose a file contains an unspecified number of double values that were written to
the file using the writeDouble method using a DataOutputStream , how do you
write a program to read all these values? How do you detect the end of a file?

17.15

What is written to a file using writeByte(91) on a FileOutputStream ?

17.16

How do you check the end of a file in an input stream ( FileInputStream ,
DataInputStream )?

17.17

What is wrong in the following code?

import java.io.*;

public class Test {