org.apache.velocity.runtime.resource.Resource Maven / Gradle / Ivy
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package org.apache.velocity.runtime.resource;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.resource.loader.ResourceLoader;
import org.slf4j.Logger;
/**
* This class represent a general text resource that
* may have been retrieved from any number of possible
* sources.
*
* @author Jason van Zyl
* @author Geir Magnusson Jr.
* @version $Id$
*/
public abstract class Resource
{
protected RuntimeServices rsvc = null;
protected Logger log = null;
/**
* The template loader that initially loaded the input
* stream for this template, and knows how to check the
* source of the input stream for modification.
*/
protected ResourceLoader resourceLoader;
/**
* The number of milliseconds in a minute, used to calculate the
* check interval.
*/
protected static final long MILLIS_PER_SECOND = 1000;
/**
* How often the file modification time is checked (in seconds).
*/
protected long modificationCheckInterval = 0;
/**
* The file modification time (in milliseconds) for the cached template.
*/
protected long lastModified = 0;
/**
* The next time the file modification time will be checked (in
* milliseconds).
*/
protected long nextCheck = 0;
/**
* Name of the resource
*/
protected String name;
/**
* Character encoding of this resource
*/
protected String encoding = RuntimeConstants.ENCODING_DEFAULT;
/**
* Resource might require ancillary storage of some kind
*/
protected Object data = null;
/**
* Resource type (RESOURCE_TEMPLATE or RESOURCE_CONTENT)
*/
protected int type;
/**
* Default constructor
*/
public Resource()
{
}
/**
* @param rs
*/
public void setRuntimeServices( RuntimeServices rs )
{
rsvc = rs;
log = rsvc.getLog("loader");
}
/**
* Perform any subsequent processing that might need
* to be done by a resource. In the case of a template
* the actual parsing of the input stream needs to be
* performed.
*
* @return Whether the resource could be processed successfully.
* For a {@link org.apache.velocity.Template} or {@link
* org.apache.velocity.runtime.resource.ContentResource}, this
* indicates whether the resource could be read.
* @exception ResourceNotFoundException Similar in semantics as
* returning false.
* @throws ParseErrorException
*/
public abstract boolean process()
throws ResourceNotFoundException, ParseErrorException;
/**
* @return True if source has been modified.
*/
public boolean isSourceModified()
{
return resourceLoader.isSourceModified(this);
}
/**
* Set the modification check interval.
* @param modificationCheckInterval The interval (in seconds).
*/
public void setModificationCheckInterval(long modificationCheckInterval)
{
this.modificationCheckInterval = modificationCheckInterval;
}
/**
* Is it time to check to see if the resource
* source has been updated?
* @return True if resource must be checked.
*/
public boolean requiresChecking()
{
/*
* short circuit this if modificationCheckInterval == 0
* as this means "don't check"
*/
if (modificationCheckInterval <= 0 )
{
return false;
}
/*
* see if we need to check now
*/
return ( System.currentTimeMillis() >= nextCheck );
}
/**
* 'Touch' this template and thereby resetting
* the nextCheck field.
*/
public void touch()
{
nextCheck = System.currentTimeMillis() + ( MILLIS_PER_SECOND * modificationCheckInterval);
}
/**
* Set the name of this resource, for example
* test.vm.
* @param name
*/
public void setName(String name)
{
this.name = name;
}
/**
* Get the name of this template.
* @return The name of this template.
*/
public String getName()
{
return name;
}
/**
* set the encoding of this resource
* for example, "ISO-8859-1"
* @param encoding
*/
public void setEncoding( String encoding )
{
this.encoding = encoding;
}
/**
* get the encoding of this resource
* for example, "ISO-8859-1"
* @return The encoding of this resource.
*/
public String getEncoding()
{
return encoding;
}
/**
* Return the lastModifed time of this
* resource.
* @return The lastModifed time of this resource.
*/
public long getLastModified()
{
return lastModified;
}
/**
* Set the last modified time for this
* resource.
* @param lastModified
*/
public void setLastModified(long lastModified)
{
this.lastModified = lastModified;
}
/**
* Return the template loader that pulled
* in the template stream
* @return The resource loader for this resource.
*/
public ResourceLoader getResourceLoader()
{
return resourceLoader;
}
/**
* Set the template loader for this template. Set
* when the Runtime determines where this template
* came from the list of possible sources.
* @param resourceLoader
*/
public void setResourceLoader(ResourceLoader resourceLoader)
{
this.resourceLoader = resourceLoader;
}
/**
* Set arbitrary data object that might be used
* by the resource.
* @param data
*/
public void setData(Object data)
{
this.data = data;
}
/**
* Get arbitrary data object that might be used
* by the resource.
* @return The data object for this resource.
*/
public Object getData()
{
return data;
}
/**
* Sets the type of this Resource (RESOURCE_TEMPLATE or RESOURCE_CONTENT)
* @param type RESOURCE_TEMPLATE or RESOURCE_CONTENT
* @since 1.6
*/
public void setType(int type)
{
this.type = type;
}
/**
* @return type code of the Resource
* @since 1.6
*/
public int getType()
{
return type;
}
}