Java IO.pdf - Nguyen Dang Binh

Java I/O
These methods behave like any other reader's read() methods. If the end of the array is
reached, they return -1.
The skip() method skips chars in the buf array by advancing pos without actually returning
any characters:
public long skip(long n) throws IOException
The ready() method returns true if pos is less than count; that is, if any unread characters
remain in the array:
public boolean ready() throws IOException
CharArrayReaders support marking and resetting to the limit of the length of the array.
markSupported() returns true. mark() marks the current position in the stream by setting
markedPos equal to pos. The readAheadLimit argument is for compatibility; its value is
ignored. The reset() method sets pos equal to markedPos.
public boolean markSupported()
public void mark(int readAheadLimit) throws IOException
public void reset() throws IOException
Finally, the close() method sets buf to null. Attempts to read from a CharArrayReader
after it's been closed throw IOExceptions.
public void close()
15.6 String Readers and Writers
The java.io.StringReader and java.io.StringWriter classes allow programmers to use
Reader and Writer methods to read and write strings. Like char arrays, Java strings are also
composed of pure Unicode characters. Therefore, they're good sources of data for readers and
good targets for writers. This is the other common case where readers and writers don't need
to convert between different encodings.
15.6.1 String Writers
This class would more accurately be called StringBufferWriter, but StringWriter is more
poetic. A StringWriter maintains an internal java.lang.StringBuffer object to which
written characters are appended. This buffer can easily be converted to a string as necessary.
public class StringWriter extends Writer
There is a single public constructor:
public StringWriter()
There is also a constructor that allows you to specify the initial size of the internal string
buffer. This isn't too important, because string buffers (and, by extension, string writers) are
expanded as necessary. Still, if you can estimate the size of the string in advance, it's
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