org.zkoss.web.util.resource
Class ExtendletLoader

java.lang.Object
  org.zkoss.web.util.resource.ExtendletLoader

All Implemented Interfaces:

Loader

public abstract class ExtendletLoader
extends java.lang.Object
implements Loader

A skeletal implementation of the loader used to implement an extendlet. All you have to do is to implement parse(java.io.InputStream, java.lang.String) and getExtendletContext().

Since:

3.0.6

Author:

tomyeh

See Also:

Extendlet

Constructor Summary

protected

ExtendletLoader()

Method Summary

int	getCheckPeriod() Returns the check period, or -1 if the content is never changed.
protected abstract ExtendletContext	getExtendletContext() Returns the extendlet context.
long	getLastModified(java.lang.Object src) Returns the last modified time.
java.lang.Object	load(java.lang.Object src) Loads the resource.
protected abstract java.lang.Object	parse(java.io.InputStream is, java.lang.String path) It is called to parse the resource into an intermediate format depending on Extendlet.
boolean	shallCheck(java.lang.Object src, long expiredMillis) Returns whether to call Loader.getLastModified(java.lang.Object).

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtendletLoader

protected ExtendletLoader()

Method Detail

shallCheck

public boolean shallCheck(java.lang.Object src,
                          long expiredMillis)

Description copied from interface: Loader

Returns whether to call Loader.getLastModified(java.lang.Object). If false, it assumes the current cached content is up-to-date.

Specified by:

shallCheck in interface Loader

expiredMillis - how many milli-seconds are expired after the last check. In most cases, just return true if expiredMillis > 0

getLastModified

public long getLastModified(java.lang.Object src)

Returns the last modified time.

Specified by:

getLastModified in interface Loader

load

public java.lang.Object load(java.lang.Object src)
                      throws java.lang.Exception

Description copied from interface: Loader

Loads the resource.

Specified by:

load in interface Loader

Returns:

null if not found

Throws:

java.lang.Exception - you might throw any exception which will be passed back to the caller of ResourceCache.get(java.lang.Object)

parse

protected abstract java.lang.Object parse(java.io.InputStream is,
                                          java.lang.String path)
                                   throws java.lang.Exception

It is called to parse the resource into an intermediate format depending on Extendlet.

Parameters:

is - the content of the resource

path - the path of the resource

Throws:

java.lang.Exception

getExtendletContext

protected abstract ExtendletContext getExtendletContext()

Returns the extendlet context.

getCheckPeriod

public int getCheckPeriod()

Returns the check period, or -1 if the content is never changed. Unit: milliseconds.

Default: It checks if an integer (unit: second) is assigned to a system property called org.zkoss.util.resource.extendlet.checkPeriod. If no such system property, -1 is assumed (never change). For the runtime environment the content is never changed, since all extendlet resources are packed in JAR files.