I/O Fundamentals

Java Input and Outputwe need to perform translation from a native format (one or more bytes percharacter) to two-byte characters in UNICODE.But what about binary files?Obviously we don't want to take a binary file such as a database and perform theUNICODE translation on its contents. We need two basic ways to handle data.Text I/O Versus Binary I/OJava's I/O classes are divided into two main groups, based on whether you wanttext or binary I/O.Reader and Writer classes handle text I/O. InputStream and OutputStreamclasses handle binary I/O.Any time you see "Reader" or "Writer" as part of a Java I/O class name, youshould immediately think "text I/O". Anytime you see "Stream" as part of theclass name, think "binary I/O".Reader and InputStreamJava supplies Readers and InputStreams to read data; their use is similar. Thefollowing table shows the most commonly used methods in these classes. See thejavadocs for the other methods available.Note that these two classes are abstract; you won't ever create an instance ofeither, but they provide the base implementation details for all other input classes.void close()int read()int read(type[])Closes the input. Always call this method whenyou are finished reading what you need, as it allowsthe VM to release locks on the file.Reads a single item from the file. In Reader, an itemis a char, while in InputStream it's a byte. Thereturn value will either be the item or -1 if there isno more data (end-of-file has been reached.)Attempts to fill the array with as much data aspossible. If enough data is available, the type[](char[] for Reader, byte[] for InputStream)will be filled with the data and the length of thearray will be returned.Java Input and Output -8© 1996-2003 jGuru.com. All Rights Reserved.