/*
    * Client
    *
    * $Id: Client.java,v 1.15 2005/10/03 20:07:45 stack-sf Exp $
    *
    * Created on Nov 12, 2004
    *
    * Copyright (C) 2004 Internet Archive.
    *
   * This file is part of the Heritrix web crawler (crawler.archive.org).
   *
   * Heritrix is free software; you can redistribute it and/or modify
   * it under the terms of the GNU Lesser Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * any later version.
   *
   * Heritrix 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 Public License for more details.
   *
   * You should have received a copy of the GNU Lesser Public License
   * along with Heritrix; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  package org.archive.jmx;
  
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.text.FieldPosition;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Set;
  import java.util.logging.ConsoleHandler;
  import java.util.logging.Handler;
  import java.util.logging.LogRecord;
  import java.util.logging.Logger;
  import java.util.logging.SimpleFormatter;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import javax.management.Attribute;
  import javax.management.AttributeList;
  import javax.management.InstanceNotFoundException;
  import javax.management.IntrospectionException;
  import javax.management.MBeanAttributeInfo;
  import javax.management.MBeanFeatureInfo;
  import javax.management.MBeanInfo;
  import javax.management.MBeanOperationInfo;
  import javax.management.MBeanParameterInfo;
  import javax.management.MBeanServerConnection;
  import javax.management.MalformedObjectNameException;
  import javax.management.ObjectInstance;
  import javax.management.ObjectName;
  import javax.management.ReflectionException;
  import javax.management.openmbean.CompositeData;
  import javax.management.openmbean.TabularData;
  import javax.management.remote.JMXConnector;
  import javax.management.remote.JMXConnectorFactory;
  import javax.management.remote.JMXServiceURL;
  
  
  /***
   * A Simple Command-Line JMX Client.
   * Tested against the JDK 1.5.0 JMX Agent.
   * See <a href="http://java.sun.com/j2se/1.5.0/docs/guide/management/agent.html">Monitoring
   * and Management Using JMX</a>.
   * <p>Can supply credentials and do primitive string representation of tabular
   * and composite openmbeans.
   * @author stack
   */
  public class Client {
      private static final Logger logger =
          Logger.getLogger(Client.class.getName());
      
      /***
       * Usage string.
       */
      private static final String USAGE = "Usage: java -jar" +
          " cmdline-jmxclient.jar USER:PASS HOST:PORT [BEAN] [COMMAND]\n" +
          "Options:\n" +
          " USER:PASS Username and password. Required. If none, pass '-'.\n" +
          "           E.g. 'controlRole:secret'\n" +
          " HOST:PORT Hostname and port to connect to. Required." +
          " E.g. localhost:8081.\n" +
          "           Lists registered beans if only USER:PASS and this" +
          " argument.\n" +
          " BEAN      Optional target bean name. If present we list" +
          " available operations\n" +
          "           and attributes.\n" +
          " COMMAND   Optional operation to run or attribute to fetch. If" +
          " none supplied,\n" +
          "           all operations and attributes are listed. Attributes" +
          " begin with a\n" +
         "           capital letter: e.g. 'Status' or 'Started'." +
         " Operations do not.\n" +
         "           Operations can take arguments by adding an '=' " +
         "followed by\n" +
         "           comma-delimited params. Pass multiple " +
         "attributes/operations to run\n" +
         "           more than one per invocation. Use commands 'create' and " +
         "'destroy'\n" +
         "           to instantiate and unregister beans ('create' takes name " +
         "of class).\n" +
         "           Pass 'Attributes' to get listing of all attributes and " +
         "and their\n" +
         "           values.\n" +
         "Requirements:\n" +
         " JDK1.5.0. If connecting to a SUN 1.5.0 JDK JMX Agent, remote side" +
         " must be\n" +
         " started with system properties such as the following:\n" +
         "     -Dcom.sun.management.jmxremote.port=PORT\n" +
         "     -Dcom.sun.management.jmxremote.authenticate=false\n" +
         "     -Dcom.sun.management.jmxremote.ssl=false\n" +
         " The above will start the remote server with no password. See\n" +
         " http://java.sun.com/j2se/1.5.0/docs/guide/management/agent.html" +
         " for more on\n" +
         " 'Monitoring and Management via JMX'.\n" +
         "Client Use Examples:\n" +
         " To list MBeans on a non-password protected remote agent:\n" +
         "     % java -jar cmdline-jmxclient-X.X.jar - localhost:8081 //\n" +
         "         org.archive.crawler:name=Heritrix,type=Service\n" +
         " To list attributes and attributes of the Heritrix MBean:\n" +
         "     % java -jar cmdline-jmxclient-X.X.jar - localhost:8081 //\n" +
         "         org.archive.crawler:name=Heritrix,type=Service //\n" +
         "         schedule=http://www.archive.org\n" +
         " To set set logging level to FINE on a password protected JVM:\n" +
         "     % java -jar cmdline-jmxclient-X.X.jar controlRole:secret" +
         " localhost:8081 //\n" +
         "         java.util.logging:type=Logging //\n" +
         "         setLoggerLevel=org.archive.crawler.Heritrix,FINE";
     
     /***
      * Pattern that matches a command name followed by
      * an optional equals and optional comma-delimited list
      * of arguments.
      */
     protected static final Pattern CMD_LINE_ARGS_PATTERN =
         Pattern.compile("^([^=]+)(?:(?://=)(.+))?$");
     
     private static final String CREATE_CMD_PREFIX = "create=";
     
 	public static void main(String[] args) throws Exception {
         Client client = new Client();
         // Set the logger to use our all-on-one-line formatter.
         Logger l = Logger.getLogger("");
         Handler [] hs = l.getHandlers();
         for (int i = 0; i < hs.length; i++) {
             Handler h = hs[0];
             if (h instanceof ConsoleHandler) {
                 h.setFormatter(client.new OneLineSimpleLogger());
             }
         }
         client.execute(args);
 	}
     
     protected static void usage() {
         usage(0, null);
     }
     
     protected static void usage(int exitCode, String message) {
         if (message != null && message.length() > 0) {
             System.out.println(message);
         }
         System.out.println(USAGE);
         System.exit(exitCode);
     }
 
     /***
      * Constructor.
      */
     public Client() {
         super();
     }
     
     /***
      * Parse a 'login:password' string.  Assumption is that no
      * colon in the login name.
      * @param userpass
      * @return Array of strings with login in first position.
      */
     protected String [] parseUserpass(final String userpass) {
         if (userpass == null || userpass.equals("-")) {
             return null;
         }
         int index = userpass.indexOf(':');
         if (index <= 0) {
             throw new RuntimeException("Unable to parse: " +userpass);
         }
         return new String [] {userpass.substring(0, index),
             userpass.substring(index + 1)};
     }
     
     /***
      * @param login
      * @param password
      * @return Credentials as map for RMI.
      */
     protected Map formatCredentials(final String login,
             final String password) {
         Map env = null;
         String[] creds = new String[] {login, password};
         env = new HashMap(1);
         env.put(JMXConnector.CREDENTIALS, creds);
         return env;
     }
     
     protected JMXConnector getJMXConnector(final String hostport,
             final String login, final String password)
     throws IOException {
         // Make up the jmx rmi URL and get a connector.
         JMXServiceURL rmiurl = new JMXServiceURL("service:jmx:rmi://"
             + hostport + "/jndi/rmi://" + hostport + "/jmxrmi");
         return JMXConnectorFactory.connect(rmiurl,
             formatCredentials(login, password));
     }
     
     protected ObjectName getObjectName(final String beanname)
     throws MalformedObjectNameException, NullPointerException {
         return notEmpty(beanname)? new ObjectName(beanname): null;
     }
     
     /***
      * Version of execute called from the cmdline.
      * Prints out result of execution on stdout.
      * Parses cmdline args.  Then calls {@link #execute(String, String,
      * String, String, String[], boolean)}.
      * @param args Cmdline args.
      * @throws Exception
      */
     protected void execute(final String [] args)
     throws Exception {
         // Process command-line.
         if (args.length == 0 || args.length == 1) {
             usage();
         }
         String userpass = args[0];
         String hostport = args[1];
         String beanname = null;
         String [] command = null;
         if (args.length > 2) {
             beanname = args[2];
         }
         if (args.length > 3) {
             command = new String [args.length - 3];
             for (int i = 3; i < args.length; i++) {
                 command[i - 3] = args[i];
             }
         }
         String [] loginPassword = parseUserpass(userpass);
         Object [] result = execute(hostport,
             ((loginPassword == null)? null: loginPassword[0]),
             ((loginPassword == null)? null: loginPassword[1]), beanname,
             command);
         // Print out results on stdout. Only log if a result.
         if (result != null) {
             for (int i = 0; i < result.length; i++) {
                 if (result[i] != null && result[i].toString().length() > 0) {
                     if (command != null) {
                         logger.info(command[i] + ": " + result[i]);
                     } else {
                         logger.info("\n" + result[i].toString());
                     }
                 }
             }
         }
     }
     
     protected Object [] execute(final String hostport, final String login,
             final String password, final String beanname,
             final String [] command)
     throws Exception {
         return execute(hostport, login, password, beanname, command, false);
     }
 
     public Object [] executeOneCmd(final String hostport, final String login,
             final String password, final String beanname,
             final String command)
     throws Exception {
         return execute(hostport, login, password, beanname,
             new String[] {command}, true);
     }
     
     /***
      * Execute command against remote JMX agent.
      * @param hostport 'host:port' combination.
      * @param login RMI login to use.
      * @param password RMI password to use.
      * @param beanname Name of remote bean to run command against.
      * @param command Array of commands to run.
      * @param oneBeanOnly Set true if passed <code>beanname</code> is
      * an exact name and the query for a bean is only supposed to return
      * one bean instance. If not, we raise an exception (Otherwise, if false,
      * then we deal with possibility of multiple bean instances coming back
      * from query). Set to true when want to get an attribute or run an
      * operation.
      * @return Array of results -- one per command.
      * @throws Exception
      */
     protected Object [] execute(final String hostport, final String login,
             final String password, final String beanname,
             final String [] command, final boolean oneBeanOnly)
     throws Exception {
         JMXConnector jmxc = getJMXConnector(hostport, login, password);
         Object [] result = null;
         try {
             result = doBeans(jmxc.getMBeanServerConnection(),
                 getObjectName(beanname), command, oneBeanOnly);
         } finally {
             jmxc.close();
         }
         return result;
     }
     
     protected boolean notEmpty(String s) {
         return s != null && s.length() > 0;
     }
         
     protected Object [] doBeans(final MBeanServerConnection mbsc,
         final ObjectName objName, final String[] command,
         final boolean oneBeanOnly)
     throws Exception {
         Object [] result = null;
         Set beans = mbsc.queryMBeans(objName, null);
         if (beans.size() == 0) {
             // No bean found. Check if we are to create a bean?
             if (command.length == 1 && notEmpty(command[0])
                     && command[0].startsWith(CREATE_CMD_PREFIX)) {
                 String className =
                     command[0].substring(CREATE_CMD_PREFIX.length());
                 mbsc.createMBean(className, objName);
             } else {
                 // TODO: Is there a better JMX exception that RE for this
                 // scenario?
                 throw new RuntimeException(objName.getCanonicalName() +
                     " not registered.");
             }
         } else if (beans.size() == 1) {
             result = doBean(mbsc, (ObjectInstance) beans.iterator().next(),
                 command);
         } else {
             if (oneBeanOnly) {
                 throw new RuntimeException("Only supposed to be one bean " +
                     "query result");
             }
             // This is case of multiple beans in query results.
             // Print name of each into a StringBuffer.  Return as one
             // result.
             StringBuffer buffer = new StringBuffer();
             for (Iterator i = beans.iterator(); i.hasNext();) {
                 Object obj = i.next();
                 if (obj instanceof ObjectName) {
                     buffer.append((((ObjectName) obj).getCanonicalName()));
                 } else if (obj instanceof ObjectInstance) {
                     buffer.append((((ObjectInstance) obj).getObjectName()
                         .getCanonicalName()));
                 } else {
                     throw new RuntimeException("Unexpected object type: " + obj);
                 }
                 buffer.append("\n");
             }
             result = new String [] {buffer.toString()};
         }
         return result;
     }
     
     /***
      * Get attribute or run operation against passed bean <code>instance</code>.
      * 
      * @param mbsc Server connection.
      * @param instance Bean instance we're to get attributes from or run
      * operation against.
      * @param command Command to run (May be null).
      * @return Result.  If multiple commands, multiple results.
      * @throws Exception
      */
     protected Object [] doBean(MBeanServerConnection mbsc,
         ObjectInstance instance, String [] command)
     throws Exception {
         // If no command, then print out list of attributes and operations.
         if (command == null || command.length <= 0) {
             return new String [] {listOptions(mbsc, instance)};
         }
         
         // Maybe multiple attributes/operations listed on one command line.
         Object [] result = new Object[command.length];
         for (int i = 0; i < command.length; i++) {
             result[i] = doSubCommand(mbsc, instance, command[i]);
         }
         return result;
     }
     
     public Object doSubCommand(MBeanServerConnection mbsc,
         ObjectInstance instance, String subCommand)
     throws Exception {
         // First, handle special case of our being asked to destroy a bean.
         if (subCommand.equals("destroy")) {
             mbsc.unregisterMBean(instance.getObjectName());
             return null;
         } else if (subCommand.startsWith(CREATE_CMD_PREFIX)) {
             throw new IllegalArgumentException("You cannot call create " +
                     "on an already existing bean.");
         }
         
         // Get attribute and operation info.
         MBeanAttributeInfo [] attributeInfo =
             mbsc.getMBeanInfo(instance.getObjectName()).getAttributes();
         MBeanOperationInfo [] operationInfo =
             mbsc.getMBeanInfo(instance.getObjectName()).getOperations();
         // Now, bdbje JMX bean doesn't follow the convention of attributes
         // having uppercase first letter and operations having lowercase
         // first letter.  But most beans do. Be prepared to handle the bdbje
         // case.
         Object result = null;
         if (Character.isUpperCase(subCommand.charAt(0))) {
             // Probably an attribute.
             if (!isFeatureInfo(attributeInfo, subCommand) &&
                     isFeatureInfo(operationInfo, subCommand)) {
                 // Its not an attribute name. Looks like its name of an
                 // operation.  Try it.
                 result =
                     doBeanOperation(mbsc, instance, subCommand, operationInfo);
             } else {
                 // Then it is an attribute OR its not an attribute name nor
                 // operation name and the below invocation will throw a
                 // AttributeNotFoundException.
                 result = doAttributeOperation(mbsc, instance, subCommand,
                     attributeInfo);
             }
         } else {
             // Must be an operation.
             if (!isFeatureInfo(operationInfo, subCommand) &&
                     isFeatureInfo(attributeInfo, subCommand)) {
                 // Its not an operation name but looks like it could be an
                 // attribute name. Try it.
                 result = doAttributeOperation(mbsc, instance, subCommand,
                     attributeInfo);        
             } else {
                 // Its an operation name OR its neither operation nor attribute
                 // name and the below will throw a NoSuchMethodException.
                 result =
                     doBeanOperation(mbsc, instance, subCommand, operationInfo);
             }
         }
         
         // Look at the result.  Is it of composite or tabular type?
         // If so, convert to a String representation.
         if (result instanceof CompositeData) {
             result = recurseCompositeData(new StringBuffer("\n"), "", "",
                 (CompositeData)result);
         } else if (result instanceof TabularData) {
             result = recurseTabularData(new StringBuffer("\n"), "", "",
                  (TabularData)result);
         } else if (result instanceof String []) {
             String [] strs = (String [])result;
             StringBuffer buffer = new StringBuffer("\n");
             for (int i = 0; i < strs.length; i++) {
                 buffer.append(strs[i]);
                 buffer.append("\n");
             }
             result = buffer;
         } else if (result instanceof AttributeList) {
             AttributeList list = (AttributeList)result;
             if (list.size() <= 0) {
                 result = null;
             } else {
                 StringBuffer buffer = new StringBuffer("\n");
                 for (Iterator ii = list.iterator(); ii.hasNext();) {
                     Attribute a = (Attribute)ii.next();
                     buffer.append(a.getName());
                     buffer.append(": ");
                     buffer.append(a.getValue());
                     buffer.append("\n");
                 }
                 result = buffer;
             }
         }
         return result;
     }
     
     protected boolean isFeatureInfo(MBeanFeatureInfo [] infos, String cmd) {
         return getFeatureInfo(infos, cmd) != null;
     }
     
     protected MBeanFeatureInfo getFeatureInfo(MBeanFeatureInfo [] infos,
             String cmd) {
         // Cmd may be carrying arguments.  Don't count them in the compare.
         int index = cmd.indexOf('=');
         String name = (index > 0)? cmd.substring(0, index): cmd;
         for (int i = 0; i < infos.length; i++) {
             if (infos[i].getName().equals(name)) {
                 return infos[i];
             }
         }
         return null;
     }
     
     protected StringBuffer recurseTabularData(StringBuffer buffer,
             String indent, String name, TabularData data) {
         addNameToBuffer(buffer, indent, name);
         java.util.Collection c = data.values();
         for (Iterator i = c.iterator(); i.hasNext();) {
             Object obj = i.next();
             if (obj instanceof CompositeData) {
                 recurseCompositeData(buffer, indent + " ", "",
                     (CompositeData)obj);
             } else if (obj instanceof TabularData) {
                 recurseTabularData(buffer, indent, "",
                     (TabularData)obj);
             } else {
                 buffer.append(obj);
             }
         }
         return buffer;
     }
     
     protected StringBuffer recurseCompositeData(StringBuffer buffer,
             String indent, String name, CompositeData data) {
         indent = addNameToBuffer(buffer, indent, name);
         for (Iterator i = data.getCompositeType().keySet().iterator();
                 i.hasNext();) {
             String key = (String)i.next();
             Object o = data.get(key);
             if (o instanceof CompositeData) {
                 recurseCompositeData(buffer, indent + " ", key,
                     (CompositeData)o);
             } else if (o instanceof TabularData) {
                 recurseTabularData(buffer, indent, key, (TabularData)o);
             } else {
                 buffer.append(indent);
                 buffer.append(key);
                 buffer.append(": ");
                 buffer.append(o);
                 buffer.append("\n");
             }
         }
         return buffer;
     }
     
     protected String addNameToBuffer(StringBuffer buffer, String indent,
             String name) {
         if (name == null || name.length() == 0) {
             return indent;
         }
         buffer.append(indent);
         buffer.append(name);
         buffer.append(":\n");
         // Move all that comes under this 'name' over by one space.
         return indent + " ";
     }
     
     /***
      * Class that parses commandline arguments.
      * Expected format is 'operationName=arg0,arg1,arg2...'. We are assuming no
      * spaces nor comma's in argument values.
      */
     protected class CommandParse {
         private String cmd;
         private String [] args;
         
         protected CommandParse(String command) throws ParseException {
             parse(command);
         }
         
         private void parse(String command) throws ParseException {
             Matcher m = CMD_LINE_ARGS_PATTERN.matcher(command);
             if (m == null || !m.matches()) {
                 throw new ParseException("Failed parse of " + command, 0);
             }
 
             this.cmd = m.group(1);
             if (m.group(2) != null && m.group(2).length() > 0) {
                 this.args = m.group(2).split(",");
             } else {
                 this.args = null;
             }
         }
         
         protected String getCmd() {
             return this.cmd;
         }
         
         protected String [] getArgs() {
             return this.args;
         }
     }
     
     protected Object doAttributeOperation(MBeanServerConnection mbsc,
         ObjectInstance instance, String command, MBeanAttributeInfo [] infos)
     throws Exception {
         // Usually we get attributes. If an argument, then we're being asked
         // to set attribute.
         CommandParse parse = new CommandParse(command);
         if (parse.getArgs() == null || parse.getArgs().length == 0) {
             // Special-casing.  If the subCommand is 'Attributes', then return
             // list of all attributes.
             if (command.equals("Attributes")) {
                 String [] names = new String[infos.length];
                 for (int i = 0; i < infos.length; i++) {
                     names[i] = infos[i].getName();
                 }
                 return mbsc.getAttributes(instance.getObjectName(), names);
             }
             return mbsc.getAttribute(instance.getObjectName(), parse.getCmd());
         }
         if (parse.getArgs().length != 1) {
             throw new IllegalArgumentException("One only argument setting " +
                 "attribute values: " + parse.getArgs());
         }
         // Get first attribute of name 'cmd'. Assumption is no method
         // overrides.  Then, look at the attribute and use its type.
         MBeanAttributeInfo info =
             (MBeanAttributeInfo)getFeatureInfo(infos, parse.getCmd());
         java.lang.reflect.Constructor c = Class.forName(
              info.getType()).getConstructor(new Class[] {String.class});
         Attribute a = new Attribute(parse.getCmd(),
             c.newInstance(new Object[] {parse.getArgs()[0]}));
         mbsc.setAttribute(instance.getObjectName(), a);
         return null;
     }
 
     protected Object doBeanOperation(MBeanServerConnection mbsc,
         ObjectInstance instance, String command, MBeanOperationInfo [] infos)
     throws Exception {
         // Parse command line.
         CommandParse parse = new CommandParse(command);
         
         // Get first method of name 'cmd'. Assumption is no method
         // overrides.  Then, look at the method and use its signature
         // to make sure client sends over parameters of the correct type.
         MBeanOperationInfo op =
             (MBeanOperationInfo)getFeatureInfo(infos, parse.getCmd());
         Object result = null;
         if (op == null) {
             result = "Operation " + parse.getCmd() + " not found.";
         } else {
             MBeanParameterInfo [] paraminfos = op.getSignature();
             int paraminfosLength = (paraminfos == null)? 0: paraminfos.length;
             int objsLength = (parse.getArgs() == null)?
                 0: parse.getArgs().length;
             if (paraminfosLength != objsLength) {
                 result = "Passed param count does not match signature count";
             } else {
                 String [] signature = new String[paraminfosLength];
                 Object [] params = (paraminfosLength == 0)? null
                         : new Object[paraminfosLength];
                 for (int i = 0; i < paraminfosLength; i++) {
                     MBeanParameterInfo paraminfo = paraminfos[i];
                     java.lang.reflect.Constructor c = Class.forName(
                         paraminfo.getType()).getConstructor(
                             new Class[] {String.class});
                     params[i] =
                         c.newInstance(new Object[] {parse.getArgs()[i]});
                     signature[i] = paraminfo.getType();
                 }
                 result = mbsc.invoke(instance.getObjectName(), parse.getCmd(),
                     params, signature);
             }
         }
         return result;
     }
 
     protected String listOptions(MBeanServerConnection mbsc,
             ObjectInstance instance)
     throws InstanceNotFoundException, IntrospectionException,
             ReflectionException, IOException {
         StringBuffer result = new StringBuffer();
         MBeanInfo info = mbsc.getMBeanInfo(instance.getObjectName());
         MBeanAttributeInfo [] attributes  = info.getAttributes();
         if (attributes.length > 0) {
             result.append("Attributes:");
             result.append("\n");
             for (int i = 0; i < attributes.length; i++) {
                 result.append(' ' + attributes[i].getName() +
                     ": " + attributes[i].getDescription() +
                     " (type=" + attributes[i].getType() +
                     ")");
                 result.append("\n");
             }
         }
         MBeanOperationInfo [] operations = info.getOperations();
         if (operations.length > 0) {
             result.append("Operations:");
             result.append("\n");
             for (int i = 0; i < operations.length; i++) {
                 MBeanParameterInfo [] params = operations[i].getSignature();
                 StringBuffer paramsStrBuffer = new StringBuffer();
                 if (params != null) {
                     for (int j = 0; j < params.length; j++) {
                         paramsStrBuffer.append("\n   name=");
                         paramsStrBuffer.append(params[j].getName());
                         paramsStrBuffer.append(" type=");
                         paramsStrBuffer.append(params[j].getType());
                         paramsStrBuffer.append(" ");
                         paramsStrBuffer.append(params[j].getDescription());
                     }
                 }
                 result.append(' ' + operations[i].getName() +              
                     ": " + operations[i].getDescription() +
                     "\n  Parameters " + params.length +
                     ", return type=" + operations[i].getReturnType() +
                     paramsStrBuffer.toString());
                 result.append("\n");
             }
         }
         return result.toString();
     }
     
     /***
      * Logger that writes entry on one line with less verbose date.
      * Modelled on the OneLineSimpleLogger from Heritrix.
      * 
      * @author stack
      * @version $Revision: 1.15 $, $Date: 2005/10/03 20:07:45 $
      */
     private class OneLineSimpleLogger extends SimpleFormatter {
         /***
          * Date instance.
          * 
          * Keep around instance of date.
          */
         private Date date = new Date();
         
         /***
          * Field position instance.
          * 
          * Keep around this instance.
          */
         private FieldPosition position = new FieldPosition(0);
         
         /***
          * MessageFormatter for date.
          */
         private SimpleDateFormat formatter =
             new SimpleDateFormat("MM/dd/yyyy HH:mm:ss Z");
         
         /***
          * Persistent buffer in which we conjure the log.
          */
         private StringBuffer buffer = new StringBuffer();
         
 
         public OneLineSimpleLogger() {
             super();
         }
         
         public synchronized String format(LogRecord record) {
             this.buffer.setLength(0);
             this.date.setTime(record.getMillis());
             this.position.setBeginIndex(0);
             this.formatter.format(this.date, this.buffer, this.position);
             this.buffer.append(' ');
             if (record.getSourceClassName() != null) {
                 this.buffer.append(record.getSourceClassName());
             } else {
                 this.buffer.append(record.getLoggerName());
             }
             this.buffer.append(' ');
             this.buffer.append(formatMessage(record));
             this.buffer.append(System.getProperty("line.separator"));
             if (record.getThrown() != null) {
                 try {
                     StringWriter writer = new StringWriter();
                     PrintWriter printer = new PrintWriter(writer);
                     record.getThrown().printStackTrace(printer);
                     writer.close();
                     this.buffer.append(writer.toString());
                 } catch (Exception e) {
                     this.buffer.append("Failed to get stack trace: " +
                         e.getMessage());
                 }
             }
             return this.buffer.toString();
         }
     }
 }