This class is a FilterInputStream that implements a one-byte pushback buffer or, as of Java 1.1, a pushback buffer of a specified length. The unread( ) methods push bytes back into the stream; these bytes are the first ones read by the next call to a read( ) method. This class is sometimes useful when writing parsers. See also PushbackReader.

Figure 9-51. java.io.PushbackInputStream

public class PushbackInputStream extends FilterInputStream {
// Public Constructors
     public PushbackInputStream(InputStream in);  
1.1  public PushbackInputStream(InputStream in, int size);  
// Public Instance Methods
     public void unread(int b) throws IOException;  
1.1  public void unread(byte[ ] b) throws IOException;  
1.1  public void unread(byte[ ] b, int off, int len) throws IOException;  
// Public Methods Overriding FilterInputStream
     public int available( ) throws IOException;  
1.2  public void close( ) throws IOException;                   synchronized
5.0  public void mark(int readlimit);                         synchronized empty
     public boolean markSupported( );                                     constant
     public int read( ) throws IOException;  
     public int read(byte[ ] b, int off, int len) throws IOException;  
5.0  public void reset( ) throws IOException;                   synchronized
1.2  public long skip(long n) throws IOException;  
// Protected Instance Fields
1.1  protected byte[ ] buf;  
1.1  protected int pos;  
}