com.hp.hpl.sparta

Class Sparta

java.lang.Object

com.hp.hpl.sparta.Sparta

public class Sparta
extends Object

This utility class allows you to configure some low-level behavior of the Sparta code such as caching and String interning. If you do not set any of the configurations here then sparta will use default implementations that will work in smaller JVMs such as J2ME. However if you are running in a bigger JVM then you will get better performance if you ocerride the defaults as described in the method descriptions below. Note that these static methods need to be called before any Sparta classes are loaded, therefore it is best to call them in a static block at the very beginning of your main application class.

Copyright (C) 2003 Hewlett-Packard Company. This file is part of Sparta, an XML Parser, DOM, and XPath library. 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.

Version:

$Date: 2003/07/18 01:48:41 $ $Revision: 1.2 $

Author:

Eamonn O'Brien-Strain

See Also:

GNU Lesser General Public License

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Sparta.Cache What a CacheFactory generates.
static interface	Sparta.CacheFactory You should pass an object that implements this interface to setCacheFactory.
static interface	Sparta.Internment Pass an object that implements this interface to setInternment.

Constructor Summary

Constructors

Constructor and Description
Sparta()

Method Summary

Methods

Modifier and Type	Method and Description
static String	intern(String s) Used internally by Sparta code to intern strings because the String.intern method is not supported in older and smaller JVMs.
static void	setCacheFactory(Sparta.CacheFactory f) Change the caching to something custom.
static void	setInternment(Sparta.Internment i) Change the String intern to something custom.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Sparta

public Sparta()

Method Detail

intern

public static String intern(String s)

Used internally by Sparta code to intern strings because the String.intern method is not supported in older and smaller JVMs.

See Also:

String.intern()

setInternment

public static void setInternment(Sparta.Internment i)

Change the String intern to something custom. For example if you are running on a modern full J2EE or JDSE JVM you almost certainly want to tell Sparta to use the standard String.inter method like this:

  public class MyApplication {
  static{
      Sparta.setInternment(new Sparta.Internment(){
          public String intern(String s) {
              return s.intern();
          }
      });
  }
  public static void main(String[] args) {
    ...

  

setCacheFactory

public static void setCacheFactory(Sparta.CacheFactory f)

Change the caching to something custom. The default CacheFactory simply creates Hashtables which grow without bound. If you are running Sparta in a long-lived application and you want to avoid memory leaks you should use caches that automatically evict using, for example an LRU mechanism or soft reference. For example if you have a class called LruMap that sub-classes from hava.util.Map then you can tell Sparta to use that by as follows

 
  public class MyApplication {
  static private class LruCache extends LruMap implements Sparta.Cache {}
  static{
      Sparta.setCacheFactory(new Sparta.CacheFactory(){
          public Sparta.Cache create() {
              return new SoftCache();
          }
      });
  }
  public static void main(String[] args) {
    ...