mss · September 1, 2014 15:53 · Sep 1, 2014
diff --git a/InternetAddress.java b/InternetAddress.java
@@ -0,0 +1,67 @@
+/* [...]
+ *
+ * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common Development
+ * and Distribution License("CDDL") (collectively, the "License").  [...]
+ */
+
+package javax.mail.internet;
+
+// [...]
+
+public class InternetAddress extends Address implements Cloneable {
+
+// [...]
+
+    /**
+     * Return an InternetAddress object representing the current user.
+     * The entire email address may be specified in the "mail.from"
+     * property.  If not set, the "mail.user" and "mail.host" properties
+     * are tried.  If those are not set, the "user.name" property and
+     * <code>InetAddress.getLocalHost</code> method are tried.
+     * Security exceptions that may occur while accessing this information
+     * are ignored.  If it is not possible to determine an email address,
+     * null is returned.
+     *
+     * @param   session         Session object used for property lookup
+     * @return                  current user's email address
+     */
+    public static InternetAddress getLocalAddress(Session session) {
+        String user=null, host=null, address=null;
+        try {
+            if (session == null) {
+                user = System.getProperty("user.name");
+                host = InetAddress.getLocalHost().getHostName();
+            } else {
+                address = session.getProperty("mail.from");
+                if (address == null) {
+                    user = session.getProperty("mail.user");
+                    if (user == null || user.length() == 0)
+                        user = session.getProperty("user.name");
+                    if (user == null || user.length() == 0)
+                        user = System.getProperty("user.name");
+                    host = session.getProperty("mail.host");
+                    if (host == null || host.length() == 0) {
+                        InetAddress me = InetAddress.getLocalHost();
+                        if (me != null)
+                            host = me.getHostName();
+                    }
+                }
+            }
+
+            if (address == null && user != null && user.length() != 0 &&
+                    host != null && host.length() != 0)
+                address = user + "@" + host;
+
+            if (address != null)
+                return new InternetAddress(address);
+        } catch (SecurityException sex) {       // ignore it
+        } catch (AddressException ex) {         // ignore it
+        } catch (UnknownHostException ex) { }   // ignore it
+        return null;
+    }
+
+// [...]
+}
diff --git a/UniqueValue.java b/UniqueValue.java
@@ -0,0 +1,60 @@
+/* [...]
+ *
+ * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common Development
+ * and Distribution License("CDDL") (collectively, the "License").  [...]
+ */
+
+package javax.mail.internet;
+
+// [...]
+
+class UniqueValue {
+
+// [...]
+
+    /**
+     * Get a unique value for use in a Message-ID.
+     *
+     * This implementation generates it by concatenating a newly
+     * created object's <code>hashCode()</code>, a global ID
+     * (incremented on every use), the current
+     * time (in milliseconds), the string "JavaMail", and
+     * this user's local address generated by 
+     * <code>InternetAddress.getLocalAddress()</code>.
+     * (The address defaults to "javamailuser@localhost" if
+     * <code>getLocalAddress()</code> returns null.)
+     *
+     * @param ssn Session object used to get the local address
+     * @see javax.mail.internet.InternetAddress
+     */
+    public static String getUniqueMessageIDValue(Session ssn) {
+        String suffix = null;
+
+        InternetAddress addr = InternetAddress.getLocalAddress(ssn);
+        if (addr != null)
+            suffix = addr.getAddress();
+        else {
+            suffix = "javamailuser@localhost"; // worst-case default
+        }
+
+        StringBuffer s = new StringBuffer();
+
+        // Unique string is <hashcode>.<id>.<currentTime>.JavaMail.<suffix>
+        s.append(s.hashCode()).append('.').append(getUniqueId()).append('.').
+          append(System.currentTimeMillis()).append('.').
+          append("JavaMail.").
+          append(suffix);
+        return s.toString();
+    }
+
+    /**
+     * Ensure ID is unique by synchronizing access.
+     * XXX - Could use AtomicInteger.getAndIncrement() in J2SE 5.0.
+     */
+    private static synchronized int getUniqueId() {
+        return id++;
+    }
+}