Input and Output Streams |
You attach a filtered stream to another stream to filter the data as it's read from or written to the original stream. The java.io package contains these filtered streams which are subclasses of either FilterInputStream or FilterOutputStream:This section shows you how to use filtered streams through an example that uses a DataInputStream and a DataOutputStream. In addition, this section shows you how to write your own filtered streams.
- DataInputStream and DataOutputStream
- BufferedInputStream and BufferedOutputStream
- LineNumberInputStream
- PushbackInputStream
- PrintStream (this is an output stream)
Using Filtered Streams
To use a filtered input (output) stream, you attach the filtered stream to another input (output) stream. You attach a filtered stream to another stream when you create it. For example, you can attach a DataInputStream to the standard input stream like this:You might do this so that you can use the more convenientDataInputStream dis = new DataInputStream(System.in.read()); String input; while ((input = dis.readLine()) != null) { . . . // do something interesting here }readXXX()
methods, such asreadLine()
, implemented by DataInputStream.Using DataInputStream and DataOutputStream
This page provides and explains an example of using DataInputStream and DataOutputStream, two filtered streams that can read and write primitive Java data types.Writing Your Own Filtered Streams
Many programmers find that they need to implement their own streams that filter or process data as it is being written to or read from the stream. Sometimes the processing is independent of the format of the data, such as counting various items in the stream, and sometimes the processing is directly related to the data itself or the format of the data, such as reading and writing data that is contained in rows and columns. Often, these programmers subclass FilterOutputStream and FilterInputStream to achieve their goals.See Also
FilterOutputStream
FilterInputStream
Input and Output Streams |