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CRLFTerminatedReader.javaAPI DocApache James 2.3.16515Fri Jan 12 12:56:32 GMT 2007org.apache.james.util

CRLFTerminatedReader

public class CRLFTerminatedReader extends Reader
A Reader for use with SMTP or other protocols in which lines must end with CRLF. Extends Reader and overrides its readLine() method. The Reader readLine() method cannot serve for SMTP because it ends lines with either CR or LF alone.

Fields Summary
InputStream
in
Constructs this CRLFTerminatedReader.
private StringBuffer
lineBuffer
private final int
EOF
private final int
CR
private final int
LF
private int
tainted
Constructors Summary
public CRLFTerminatedReader(InputStream in)

    this.in = in;
public CRLFTerminatedReader(InputStream in, String enc)

        this(in);
Methods Summary
public voidclose()

    in.close();
public intread()

    return in.read();
public intread(char[] cbuf, int off, int len)

    byte [] temp = new byte[len];
    int result = in.read(temp, 0, len);
    for (int i=0;i<result;i++) cbuf[i] = (char) temp[i];
    return result;
public java.lang.StringreadLine()
Read a line of text which is terminated by CRLF. The concluding CRLF characters are not returned with the String, but if either CR or LF appears in the text in any other sequence it is returned in the String like any other character. Some characters at the end of the stream may be lost if they are in a "line" not terminated by CRLF.

return
either a String containing the contents of a line which must end with CRLF, or null if the end of the stream has been reached, possibly discarding some characters in a line not terminated with CRLF.
throws
IOException if an I/O error occurs.


                                                                                                                              
        

        //start with the StringBuffer empty
        lineBuffer.delete(0, lineBuffer.length());

        /* This boolean tells which state we are in,
         * depending upon whether or not we got a CR
         * in the preceding read().
         */ 
        boolean cr_just_received = false;

        // Until we add support for specifying a maximum line lenth as
        // a Service Extension, limit lines to 2K, which is twice what
        // RFC 2821 4.5.3.1 requires.
        while (lineBuffer.length() <= 2048) {
            int inChar = read();

            if (!cr_just_received){
                //the most common case, somewhere before the end of a line
                switch (inChar){
                    case CR  :  cr_just_received = true;
                                break;
                    case EOF :  return null;   // premature EOF -- discards data(?)
                    case LF  :  //the normal ending of a line
                        if (tainted == -1) tainted = lineBuffer.length();
                        // intentional fall-through
                    default  :  lineBuffer.append((char)inChar);
                }
            }else{
                // CR has been received, we may be at end of line
                switch (inChar){
                    case LF  :  // LF without a preceding CR
                        if (tainted != -1) {
                            int pos = tainted;
                            tainted = -1;
                            throw new TerminationException("\"bare\" CR or LF in data stream", pos);
                        }
                        return lineBuffer.toString();
                    case EOF :  return null;   // premature EOF -- discards data(?)
                    case CR  :  //we got two (or more) CRs in a row
                        if (tainted == -1) tainted = lineBuffer.length();
                        lineBuffer.append((char)CR);
                        break;
                    default  :  //we got some other character following a CR
                        if (tainted == -1) tainted = lineBuffer.length();
                        lineBuffer.append((char)CR);
                        lineBuffer.append((char)inChar);
                        cr_just_received = false;
                }
            }
        }//while
        throw new LineLengthExceededException("Exceeded maximum line length");
public booleanready()

    return in.available() > 0;