Patch from Charlie to extract Logger.format into LogBuilder class.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2576 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/util/LogBuilder.java

@@ -0,0 +1,90 @@
+//
+// $Id$
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001-2009 Michael Bayne
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.util;
+
+/**
+ * Formats a message and an array of alternating key value pairs like so:
+ *
+ * <pre>message [key=value, key=value, key=value]</pre>
+ */
+public class LogBuilder
+{
+    /**
+     * Creates a log builder with no message and no initial key value pairs.
+     */
+    public LogBuilder ()
+    {
+        this("");
+    }
+
+    /**
+     * Creates a log builder with the given message and key value pairs.
+     */
+    public LogBuilder (Object message, Object... args)
+    {
+        _log = new StringBuilder().append(message);
+        append(args);
+    }
+
+    /**
+     * Adds the given key value pairs to the log.
+     */
+    public LogBuilder append (Object... args)
+    {
+        if (args != null && args.length > 1) {
+            for (int ii = 0, nn = args.length / 2; ii < nn; ii++) {
+                if (_hasArgs) {
+                    _log.append(", ");
+                } else {
+                    if (_log.length() > 0) {
+                        // only need a space if we have a message
+                        _log.append(' ');
+                    }
+                    _log.append('[');
+                    _hasArgs = true;
+                }
+                _log.append(args[2 * ii]).append("=");
+                try {
+                    StringUtil.toString(_log, args[2 * ii + 1]);
+                } catch (Throwable t) {
+                    _log.append("<toString() failure: " + t + ">");
+                }
+            }
+        }
+        return this;
+    }
+
+    /**
+     * Returns the formatted log message. Does not reset the buffer. You can continue to append
+     * arguments and call {@link #toString} again.
+     */
+    @Override public String toString ()
+    {
+        String log = _log.toString();
+        if (_hasArgs) {
+            log += "]";
+        }
+        return log;
+    }
+
+    protected boolean _hasArgs;
+    protected StringBuilder _log;
+}

src/java/com/samskivert/util/Logger.java

@@ -85,24 +85,7 @@ public abstract class Logger
      */
     public static String format (Object message, Object... args)
     {
-        StringBuilder buf = new StringBuilder();
-        buf.append(message);
-        if (args != null && args.length > 1) {
-            buf.append(" [");
-            for (int ii = 0, nn = args.length/2; ii < nn; ii++) {
-                if (ii > 0) {
-                    buf.append(", ");
-                }
-                buf.append(args[2*ii]).append("=");
-                try {
-                    StringUtil.toString(buf, args[2*ii+1]);
-                } catch (Throwable t) {
-                    buf.append("<toString() failure: " + t + ">");
-                }
-            }
-            buf.append("]");
-        }
-        return buf.toString();
+        return new LogBuilder(message, args).toString();
     }
 
     /**