@@ -0,0 +1,151 @@
+package eu.siacs.conversations.xmpp.jid;
+
+import java.net.IDN;
+
+import gnu.inet.encoding.Stringprep;
+import gnu.inet.encoding.StringprepException;
+
+/**
+ * The `Jid' class provides an immutable representation of a JID.
+ */
+public final class Jid {
+
+ public final static class InvalidJidException extends Exception { }
+
+ private final String localpart;
+ private final String domainpart;
+ private final String resourcepart;
+
+ // It's much more efficient to store the ful JID as well as the parts instead of figuring them
+ // all out every time (since some characters are displayed but aren't used for comparisons).
+ private final String displayjid;
+
+ public String getLocalpart() {
+ return IDN.toUnicode(localpart);
+ }
+
+ public String getDomainpart() {
+ return IDN.toUnicode(domainpart);
+ }
+
+ public String getResourcepart() {
+ return IDN.toUnicode(resourcepart);
+ }
+
+ // Special private constructor that doesn't do any checking...
+ private Jid(final String localpart, final String domainpart) {
+ this.localpart = localpart;
+ this.domainpart = domainpart;
+ this.resourcepart = "";
+ if (localpart.isEmpty()) {
+ this.displayjid = domainpart;
+ } else {
+ this.displayjid = localpart + "@" + domainpart;
+ }
+ }
+
+ // Note: If introducing a mutable instance variable for some reason, make the constructor
+ // private and add a factory method to ensure thread safety and hash-cach-ability (tm).
+ public Jid(final String jid) throws InvalidJidException {
+
+ // Hackish Android way to count the number of chars in a string... should work everywhere.
+ final int atCount = jid.length() - jid.replace("@", "").length();
+ final int slashCount = jid.length() - jid.replace("/", "").length();
+
+ // Throw an error if there's anything obvious wrong with the JID...
+ if (atCount > 1 || slashCount > 1 ||
+ jid.length() == 0 || jid.length() > 3071 ||
+ jid.startsWith("@") || jid.endsWith("@") ||
+ jid.startsWith("/") || jid.endsWith("/")) {
+ throw new InvalidJidException();
+ }
+
+ String finaljid;
+
+ final int domainpartStart;
+ if (atCount == 1) {
+ final int atLoc = jid.indexOf("@");
+ final String lp = jid.substring(0, atLoc);
+ try {
+ localpart = Stringprep.nodeprep(lp);
+ } catch (final StringprepException e) {
+ throw new InvalidJidException();
+ }
+ if (localpart.isEmpty() || localpart.length() > 1023) {
+ throw new InvalidJidException();
+ }
+ domainpartStart = atLoc;
+ finaljid = lp + "@";
+ } else {
+ localpart = "";
+ finaljid = "";
+ domainpartStart = 0;
+ }
+
+ final String dp;
+ if (slashCount == 1) {
+ final int slashLoc = jid.indexOf("/");
+ final String rp = jid.substring(slashLoc + 1, jid.length());
+ try {
+ resourcepart = Stringprep.resourceprep(rp);
+ } catch (final StringprepException e) {
+ throw new InvalidJidException();
+ }
+ if (resourcepart.isEmpty() || resourcepart.length() > 1023) {
+ throw new InvalidJidException();
+ }
+ dp = jid.substring(domainpartStart, slashLoc);
+ finaljid = finaljid + dp + "/" + rp;
+ } else {
+ resourcepart = "";
+ dp = jid.substring(domainpartStart, jid.length());
+ finaljid = finaljid + dp;
+ }
+
+ // Remove trailling "." before storing the domain part.
+ if (dp.endsWith(".")) {
+ domainpart = IDN.toASCII(dp.substring(0, dp.length() - 1), IDN.USE_STD3_ASCII_RULES);
+ } else {
+ domainpart = IDN.toASCII(dp, IDN.USE_STD3_ASCII_RULES);
+ }
+
+ // TODO: Find a proper domain validation library; validate individual parts, separators, etc.
+ if (domainpart.isEmpty() || domainpart.length() > 1023) {
+ throw new InvalidJidException();
+ }
+
+ this.displayjid = finaljid;
+ }
+
+ public Jid getBareJid() {
+ return displayjid.contains("/") ? new Jid(localpart, domainpart) : this;
+ }
+
+ @Override
+ public String toString() {
+ return displayjid;
+ }
+
+ @Override
+ public boolean equals(final Object o) {
+ if (this == o) return true;
+ if (o == null || getClass() != o.getClass()) return false;
+
+ final Jid jid = (Jid) o;
+
+ // Since we're immutable, the JVM will cache hashcodes, making this very fast.
+ // I'm assuming Dalvik does the same sorts of optimizations...
+ // Since the hashcode does not include the displayJID it can be used for IDN comparison as
+ // well.
+ return jid.hashCode() == this.hashCode();
+
+ }
+
+ @Override
+ public int hashCode() {
+ int result = localpart.hashCode();
+ result = 31 * result + domainpart.hashCode();
+ result = 31 * result + resourcepart.hashCode();
+ return result;
+ }
+}