Java The Complete Reference, Seventh Edition

1234567.123, -1234567.123);

}

}

The output is shown here:

Here are some numeric values in different formats.

Various integer formats: 3 (3) +3 00003

Default floating-point format: 1234567.123000

Floating-point with commas: 1,234,567.123000

Negative floating-point default: -1,234,567.123000

Negative floating-point option: (1,234,567.123000)

Line up positive and negative values:

1,234,567.12

-1,234,567.12

PrintStreamalso defines theformat( )method. It has these general forms:

PrintStream format(StringfmtString, Object ...args)

PrintStream format(Localeloc, StringfmtString, Object ...args)

It works exactly likeprintf( ).

DataOutputStream and DataInputStream

DataOutputStreamandDataInputStreamenable you to write or read primitive data to or

from a stream. They implement theDataOutputandDataInputinterfaces, respectively.

These interfaces define methods that convert primitive values to or from a sequence of

bytes. These streams make it easy to store binary data, such as integers or floating-point

values, in a file. Each is examined here.

DataOutputStreamextendsFilterOutputStream, which extendsOutputStream.

DataOutputStreamdefines the following constructor:

DataOutputStream(OutputStreamoutputStream)

Here,outputStreamspecifies the output stream to which data will be written.

DataOutputStreamsupports all of the methods defined by it superclasses. However,

it is the methods defined by theDataOutputinterface, which it implements, that make it

interesting.DataOutputdefines methods that convert values of a primitive type into a byte

sequence and then writes it to the underlying stream. Here is a sampling of these methods:

final void writeDouble(doublevalue) throws IOException

final void writeBoolean(booleanvalue) throws IOException

final void writeInt(intvalue) throws IOException

Here,valueis the value written to the stream.

576 Part II: The Java Library