File	Doc	Category	Size	Date	Package
CharTerminatedInputStream.java	API Doc	Apache James 2.3.1	5918	Fri Jan 12 12:56:32 GMT 2007	org.apache.james.util

CharTerminatedInputStream

• java.lang.Object
  • java.io.InputStream

Fields Summary
private InputStream	in The wrapped input stream
private int[]	match The terminating character array
private int[]	buffer An array containing the last N characters read from the stream, where N is the length of the terminating character array
private int	pos The number of bytes that have been read that have not been placed in the internal buffer.
private boolean	endFound Whether the terminating sequence has been read from the stream

Constructors Summary

public CharTerminatedInputStream(InputStream in, char[] terminator) A constructor for this object that takes a stream to be wrapped and a terminating character sequence. param in the InputStream to be wrapped param terminator the array of characters that will terminate the stream. throws IllegalArgumentException if the terminator array is null or empty if (terminator == null) { throw new IllegalArgumentException("The terminating character array cannot be null."); } if (terminator.length == 0) { throw new IllegalArgumentException("The terminating character array cannot be of zero length."); } match = new int[terminator.length]; buffer = new int[terminator.length]; for (int i = 0; i < terminator.length; i++) { match[i] = (int)terminator[i]; buffer[i] = (int)terminator[i]; } this.in = in;

Methods Summary
public int	read() Read a byte off this stream. return the byte read off the stream throws IOException if an IOException is encountered while reading off the stream throws ProtocolException if the underlying stream returns -1 before the terminator is seen. if (endFound) { //We've found the match to the terminator return -1; } if (pos == 0) { //We have no data... read in a record int b = in.read(); if (b == -1) { //End of stream reached without seeing the terminator throw new java.net.ProtocolException("pre-mature end of data"); } if (b != match[0]) { //this char is not the first char of the match return b; } //this is a match...put this in the first byte of the buffer, // and fall through to matching logic buffer[0] = b; pos++; } else { if (buffer[0] != match[0]) { //Maybe from a previous scan, there is existing data, // and the first available char does not match the // beginning of the terminating string. return topChar(); } //we have a match... fall through to matching logic. } //MATCHING LOGIC //The first character is a match... scan for complete match, // reading extra chars as needed, until complete match is found for (int i = 0; i < match.length; i++) { if (i >= pos) { int b = in.read(); if (b == -1) { //end of stream found, so match cannot be fulfilled. // note we don't set endFound, because otherwise // remaining part of buffer won't be returned. return topChar(); } //put the read char in the buffer buffer[pos] = b; pos++; } if (buffer[i] != match[i]) { //we did not find a match... return the top char return topChar(); } } //A complete match was made... endFound = true; return -1;
private int	topChar() Private helper method to update the internal buffer of last read characters return the byte that was previously at the front of the internal buffer int b = buffer[0]; if (pos > 1) { //copy down the buffer to keep the fresh data at top System.arraycopy(buffer, 1, buffer, 0, pos - 1); } pos--; return b;