Java input and output is defined in terms of an abstract concept called a “stream”, which is a sequence of data.
There are 2 kinds of streams.
There are 2 kinds of streams.
- Byte streams (8 bit bytes) ?? Abstract classes are: InputStream and OutputStream
- Character streams (16 bit UNICODE) ?? Abstract classes are: Reader and Writer
Design pattern: java.io.* classes use the decorator design pattern. The decorator design pattern attaches responsibilities to objects at runtime. Decorators are more flexible than inheritance because the inheritance attaches responsibility to classes at compile time. The java.io.* classes use the decorator pattern to construct different combinations of behaviour at runtime based on some basic classes.
File file = new File(“c:/temp”);
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
Decorators decorate an object by enhancing or restricting functionality of an object it decorates. The decorators add or restrict functionality to decorated Java objects either before or after forwarding the request. At runtime the BufferedInputStream (bis), which is a decorator (aka a wrapper around decorated object), forwards the method call to its decorated object FileInputStream (fis). The ‘bis’ will apply the additional functionality of buffering around the lower level file (i.e. fis) I/O.
