/*
* @(#)MessageHeader.java 1.8 95/08/22 James Gosling, Jonathan Payne
*
* Copyright (c) 1994 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for NON-COMMERCIAL purposes and without fee is hereby
* granted provided that this copyright notice appears in all copies. Please
* refer to the file "copyright.html" for further important copyright and
* licensing information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
* SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
* OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
* LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR
* ITS DERIVATIVES.
*/
/*-
* news stream opener
*/
package sun.net.www;
import java.io.InputStream;
import java.io.PrintStream;
/** An RFC 844 or MIME message header. Includes methods
for parsing headers from incoming streams, fetching
values, setting values, and printing headers.
Key values of null are legal: they indicate lines in
the header that don't have a valid key, but do have
a value (this isn't legal according to the standard,
but lines like this are everywhere). */
public
class MessageHeader {
private String keys[];
private String values[];
private int nkeys;
public MessageHeader () {
}
public MessageHeader (InputStream is) throws java.io.IOException {
parseHeader(is);
}
/** Find the value that corresponds to this key.
It finds only the first occurrance of the key.
Returns null if not found. */
public String findValue(String k) {
if (k == null) {
for (int i = nkeys; --i >= 0;)
if (keys[i] == null)
return values[i];
} else
for (int i = nkeys; --i >= 0;)
if (k.equalsIgnoreCase(keys[i]))
return values[i];
return null;
}
public String getKey(int n) {
if (n < 0 || n >= nkeys) return null;
String k = keys[n];
return k == null ? "NULLKEY" : k;
}
public String getValue(int n) {
if (n < 0 || n >= nkeys) return null;
return values[n];
}
/** Find the next value that corresponds to this key.
* It finds the first value that follows v. To iterate
* over all the values of a key use:
* <pre>
* for(String v=h.findValue(k); v!=null; v=h.findNextValue(k, v)) {
* ...
* }
* </pre>
*/
public String findNextValue(String k, String v) {
boolean foundV = false;
if (k == null) {
for (int i = nkeys; --i >= 0;)
if (keys[i] == null)
if (foundV)
return values[i];
else if (values[i] == v)
foundV = true;
} else
for (int i = nkeys; --i >= 0;)
if (k.equalsIgnoreCase(keys[i]))
if (foundV)
return values[i];
else if (values[i] == v)
foundV = true;
return null;
}
/** Prints the key-value pairs represented by this
header. Also prints the RFC required blank line
at the end. Omits pairs with a null key. */
public void print(PrintStream p) {
for (int i = 0; i < nkeys; i++)
if (keys[i] != null)
p.print(keys[i] + ": " + values[i] + "\n");
p.print("\n");
}
/** Adds a key value pair to the end of the
header. Duplicates are allowed */
public void add(String k, String v) {
if (keys == null || nkeys >= keys.length) {
String nk[] = new String[nkeys + 4];
String nv[] = new String[nkeys + 4];
if (keys != null)
System.arraycopy(keys, 0, nk, 0, nkeys);
if (values != null)
System.arraycopy(values, 0, nv, 0, nkeys);
keys = nk;
values = nv;
}
keys[nkeys] = k;
values[nkeys] = v;
nkeys++;
}
/** Sets the value of a key. If the key already
exists in the header, it's value will be
changed. Otherwise a new key/value pair will
be added to the end of the header. */
public void set(String k, String v) {
for (int i = nkeys; --i >= 0;)
if (k.equalsIgnoreCase(keys[i])) {
values[i] = v;
return;
}
add(k, v);
}
/** Convert a message-id string to canonical form (strips off
leading and trailing <>s) */
public String canonicalID(String id) {
if (id == null)
return "";
int st = 0;
int len = id.length();
boolean substr = false;
int c;
while (st < len && ((c = id.charAt(st)) == '<' ||
c <= ' ')) {
st++;
substr = true;
}
while (st < len && ((c = id.charAt(len - 1)) == '>' ||
c <= ' ')) {
len--;
substr = true;
}
return substr ? id.substring(st, len) : id;
}
/** Parse a MIME header from an input stream. */
public void parseHeader(InputStream is) throws java.io.IOException {
nkeys = 0;
if (is == null)
return;
char s[] = new char[10];
int firstc = is.read();
while (firstc != '\n' && firstc != '\r' && firstc >= 0) {
int len = 0;
int keyend = -1;
int c;
boolean inKey = firstc > ' ';
s[len++] = (char) firstc;
parseloop:{
while ((c = is.read()) >= 0) {
switch (c) {
case ':':
if (inKey && len > 0)
keyend = len;
inKey = false;
break;
case '\t':
c = ' ';
case ' ':
inKey = false;
break;
case '\r':
case '\n':
firstc = is.read();
if (c == '\r' && firstc == '\n') {
firstc = is.read();
if (firstc == '\r')
firstc = is.read();
}
if (firstc == '\n' || firstc == '\r' || firstc > ' ')
break parseloop;
/* continuation */
c = ' ';
break;
}
if (len >= s.length) {
char ns[] = new char[s.length * 2];
System.arraycopy(s, 0, ns, 0, len);
s = ns;
}
s[len++] = (char) c;
}
firstc = -1;
}
while (len > 0 && s[len - 1] <= ' ')
len--;
String k;
if (keyend <= 0) {
k = null;
keyend = 0;
} else {
k = String.copyValueOf(s, 0, keyend);
if (keyend < len && s[keyend] == ':')
keyend++;
while (keyend < len && s[keyend] <= ' ')
keyend++;
}
String v;
if (keyend >= len)
v = new String();
else
v = String.copyValueOf(s, keyend, len - keyend);
add(k, v);
}
}
}