freemarker.cache
Class FileTemplateLoader

java.lang.Object
  freemarker.cache.FileTemplateLoader

All Implemented Interfaces:

TemplateLoader

public class FileTemplateLoader
extends java.lang.Object
implements TemplateLoader

A TemplateLoader that uses files in a specified directory as the source of templates. If contains security checks that will prevent it serving templates outside the template directory (like <include /etc/passwd>. It compares canonical paths for this, so templates that are symbolically linked into the template directory from outside of it won't work either.

Version:

$Id: FileTemplateLoader.java,v 1.26 2004/03/29 08:06:22 szegedia Exp $

Author:

Attila Szegedi, szegedia at freemail dot hu

Field Summary

java.io.File

baseDir

Constructor Summary

FileTemplateLoader()
Creates a new file template cache that will use the current directory (the value of the system property user.dir as the base directory for loading templates.

FileTemplateLoader(java.io.File baseDir)
Creates a new file template loader that will use the specified directory as the base directory for loading templates.

FileTemplateLoader(java.io.File baseDir, boolean allowLinking)
Creates a new file template loader that will use the specified directory as the base directory for loading templates.

Method Summary

void	closeTemplateSource(java.lang.Object templateSource) Closes the template source.
java.lang.Object	findTemplateSource(java.lang.String name) Finds the object that acts as the source of the template with the given name.
long	getLastModified(java.lang.Object templateSource) Returns the time of last modification of the specified template source.
java.io.Reader	getReader(java.lang.Object templateSource, java.lang.String encoding) Returns the character stream of a template represented by the specified template source.

Methods inherited from class java.lang.Object

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

Field Detail

baseDir

public final java.io.File baseDir

Constructor Detail

FileTemplateLoader

public FileTemplateLoader()
                   throws java.io.IOException

Creates a new file template cache that will use the current directory (the value of the system property user.dir as the base directory for loading templates. It will not allow access to template files that are accessible through symlinks that point outside the base directory.

Throws:

java.io.IOException

FileTemplateLoader

public FileTemplateLoader(java.io.File baseDir)
                   throws java.io.IOException

Creates a new file template loader that will use the specified directory as the base directory for loading templates. It will not allow access to template files that are accessible through symlinks that point outside the base directory.

Parameters:

baseDir - the base directory for loading templates

Throws:

java.io.IOException

FileTemplateLoader

public FileTemplateLoader(java.io.File baseDir,
                          boolean allowLinking)
                   throws java.io.IOException

Creates a new file template loader that will use the specified directory as the base directory for loading templates.

Parameters:

baseDir - the base directory for loading templates

allowLinking - if true, it will allow

Throws:

java.io.IOException

Method Detail

findTemplateSource

public java.lang.Object findTemplateSource(java.lang.String name)
                                    throws java.io.IOException

Description copied from interface: TemplateLoader

Finds the object that acts as the source of the template with the given name. This method is called by the TemplateCache when a template is requested, before calling either TemplateLoader.getLastModified(Object) or TemplateLoader.getReader(Object, String).

Specified by:

findTemplateSource in interface TemplateLoader

Parameters:

name - the name of the template, already localized and normalized by the cache. It is completely up to the loader implementation to interpret the name, however it should expect to receive hierarchical paths where path components are separated by a slash (not backslash). Backslashes (or any other OS specific separator character) are not considered as separators by FreeMarker, and thus they will not be replaced with slash before passing to this method, so it is up to the template loader to handle them (say, be throwing and exception that tells the user that the path (s)he has entered is invalid, as (s)he must use slash -- typical mistake of Windows users). The passed names are always considered relative to some loader-defined root location (often reffered as the "template root direcotry"), and will never start with a slash, nor will they contain a path component consisting of either a single or a double dot -- these are all resolved by the template cache before passing the name to the loader. As a side effect, paths that trivially reach outside template root directory, such as ../my.ftl, will be rejected by the template cache, so they never reach the template loader. Note again, that if the path uses backslash as path separator instead of slash as (the template loader should not accept that), the normalisation will not properly happen, as FreeMarker (the cache) recognizes only the slashes as separators.

Returns:

an object representing the template source, which can be supplied in subsequent calls to TemplateLoader.getLastModified(Object) and TemplateLoader.getReader(Object, String). Null must be returned if the source for the template can not be found (do not throw FileNotFoundException!). The returned object may will be compared with a cached template source object for equality, using the equals method. Thus, objects returned for the same physical source must be equivalent according to equals method, otherwise template caching can become very ineffective!

Throws:

java.io.IOException

getLastModified

public long getLastModified(java.lang.Object templateSource)

Description copied from interface: TemplateLoader

Returns the time of last modification of the specified template source. This method is called after findTemplateSource().

Specified by:

getLastModified in interface TemplateLoader

Parameters:

templateSource - an object representing a template source, obtained through a prior call to TemplateLoader.findTemplateSource(String).

Returns:

the time of last modification of the specified template source, or -1 if the time is not known.

getReader

public java.io.Reader getReader(java.lang.Object templateSource,
                                java.lang.String encoding)
                         throws java.io.IOException

Description copied from interface: TemplateLoader

Returns the character stream of a template represented by the specified template source. This method is called after getLastModified() if it is determined that a cached copy of the template is unavailable or stale.

Specified by:

getReader in interface TemplateLoader

Parameters:

templateSource - an object representing a template source, obtained through a prior call to TemplateLoader.findTemplateSource(String).

encoding - the character encoding used to translate source bytes to characters. Some loaders may not have access to the byte representation of the template stream, and instead directly obtain a character stream. These loaders will - quite naturally - ignore the encoding parameter.

Returns:

a reader representing the template character stream. The framework will call close().

Throws:

java.io.IOException - if an I/O error occurs while accessing the stream.

closeTemplateSource

public void closeTemplateSource(java.lang.Object templateSource)

Description copied from interface: TemplateLoader

Closes the template source. This is the last method that is called by the TemplateCache for a templateSource. The framework guarantees that this method will be called on every object that is returned from TemplateLoader.findTemplateSource(String).

Specified by:

closeTemplateSource in interface TemplateLoader

Parameters:

templateSource - the template source that should be closed.