freemarker.cache

Class FileTemplateLoader

java.lang.Object

freemarker.cache.FileTemplateLoader

All Implemented Interfaces:

TemplateLoader

public class FileTemplateLoader
extends Object
implements TemplateLoader

A TemplateLoader that uses files inside a specified directory as the source of templates. By default it does security checks on the canonical path that will prevent it serving templates outside that specified directory. If you want symbolic links that point outside the template directory to work, you need to disable this feature by using FileTemplateLoader(File, boolean) with true second argument, but before that, check the security implications there!

Field Summary

Fields

Modifier and Type	Field and Description
File	baseDir
static String	SYSTEM_PROPERTY_NAME_EMULATE_CASE_SENSITIVE_FILE_SYSTEM By setting this Java system property to true, you can change the default of #getEmulateCaseSensitiveFileSystem().

Constructor Summary

Constructors

Constructor and Description
FileTemplateLoader() Deprecated. Relying on what the current directory is is a bad practice; use FileTemplateLoader(File) instead.
FileTemplateLoader(File baseDir) Creates a new file template loader that will use the specified directory as the base directory for loading templates.
FileTemplateLoader(File baseDir, boolean disableCanonicalPathCheck) Creates a new file template loader that will use the specified directory as the base directory for loading templates.

Method Summary

Modifier and Type	Method and Description
void	closeTemplateSource(Object templateSource) Closes the template source, releasing any resources held that are only required for reading the template and/or its metadata.
Object	findTemplateSource(String name) Finds the template in the backing storage and returns an object that identifies the storage location where the template can be loaded from.
File	getBaseDirectory() Returns the base directory in which the templates are searched.
boolean	getEmulateCaseSensitiveFileSystem() Getter pair of setEmulateCaseSensitiveFileSystem(boolean).
protected boolean	getEmulateCaseSensitiveFileSystemDefault() Returns the default of getEmulateCaseSensitiveFileSystem().
long	getLastModified(Object templateSource) Returns the time of last modification of the specified template source.
Reader	getReader(Object templateSource, String encoding) Returns the character stream of a template represented by the specified template source.
void	setEmulateCaseSensitiveFileSystem(boolean nameCaseChecked) Intended for development only, checks if the template name matches the case (upper VS lower case letters) of the actual file name, and if it doesn't, it emulates a file-not-found even if the file system is case insensitive.
String	toString() Show class name and some details that are useful in template-not-found errors.

Methods inherited from class java.lang.Object

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

Field Detail

SYSTEM_PROPERTY_NAME_EMULATE_CASE_SENSITIVE_FILE_SYSTEM

public static String SYSTEM_PROPERTY_NAME_EMULATE_CASE_SENSITIVE_FILE_SYSTEM

By setting this Java system property to true, you can change the default of #getEmulateCaseSensitiveFileSystem().

baseDir

public final File baseDir

Constructor Detail

FileTemplateLoader

public FileTemplateLoader()
                   throws IOException

Deprecated. Relying on what the current directory is is a bad practice; use FileTemplateLoader(File) instead.

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:

IOException

FileTemplateLoader

public FileTemplateLoader(File baseDir)
                   throws 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:

IOException

FileTemplateLoader

public FileTemplateLoader(File baseDir,
                          boolean disableCanonicalPathCheck)
                   throws IOException

Creates a new file template loader that will use the specified directory as the base directory for loading templates. See the parameters for allowing symlinks that point outside the base directory.

Parameters:

baseDir - the base directory for loading templates

disableCanonicalPathCheck - If true, it will not check if the file to be loaded is inside the baseDir or not, according the canonical paths of the baseDir and the file to load. Note that Configuration.getTemplate(String) and (its overloads) already prevents backing out from the template directory with paths like /../../../etc/password, however, that can be circumvented with symbolic links or other file system features. If you really want to use symbolic links that point outside the baseDir, set this parameter to true, but then be very careful with template paths that are supplied by the visitor or an external system.

Throws:

IOException

Method Detail

findTemplateSource

public Object findTemplateSource(String name)
                          throws IOException

Description copied from interface: TemplateLoader

Finds the template in the backing storage and returns an object that identifies the storage location where the template can be loaded from. See the return value for more information.

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's 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 referred as the "template root directory"), 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 normalization 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), when those are called on the same TemplateLoader. null must be returned if the source for the template doesn't exist; don't throw exception then! The exact type of this object is up to the TemplateLoader implementation. As this object is possibly used as hash key in caches, and is surly compared with another template source for equality, it must have a proper Object.equals(Object) and Object.hashCode()) implementation. Especially, template sources that refer to the same physical source must be equivalent, otherwise template caching can become inefficient. This is only expected from Object.equals(Object) when the compared template sources came from the same TemplateLoader instance. Also, it must not influence the equality if the source is open or closed (TemplateLoader.closeTemplateSource(Object)).

Throws:

IOException - When an error occurs that makes it impossible to find out if the template exists, or to access the existing template. Don't throw exception if the template doesn't exist, instead return with null then!

getLastModified

public long getLastModified(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). This must be an object on which TemplateLoader.closeTemplateSource(Object) wasn't applied yet.

Returns:

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

getReader

public Reader getReader(Object templateSource,
                        String encoding)
                 throws IOException

Description copied from interface: TemplateLoader

Returns the character stream of a template represented by the specified template source. This method is possibly called for multiple times for the same template source object, and it must always return a Reader that reads the template from its beginning. Before this method is called for the second time (or later), its caller must close the previously returned Reader, and it must not use it anymore. That is, this method is not required to support multiple concurrent readers for the same source templateSource object.

Typically, this method is called if the template is missing from the cache, or if after calling TemplateLoader.findTemplateSource(String) and TemplateLoader.getLastModified(Object) it was determined that the cached copy of the template is stale. Then, if it turns out that the encoding parameter used doesn't match the actual template content (based on the #ftl encoding=... header), this method will be called for a second time with the correct encoding parameter value.

Specified by:

getReader in interface TemplateLoader

Parameters:

templateSource - an object representing a template source, obtained through a prior call to TemplateLoader.findTemplateSource(String). This must be an object on which TemplateLoader.closeTemplateSource(Object) wasn't applied yet.

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 should ignore the encoding parameter.

Returns:

A Reader representing the template character stream. It's the responsibility of the caller (which is TemplateCache usually) to close() it. The Reader is not required to work after the templateSource was closed (TemplateLoader.closeTemplateSource(Object)).

Throws:

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

closeTemplateSource

public void closeTemplateSource(Object templateSource)

Description copied from interface: TemplateLoader

Closes the template source, releasing any resources held that are only required for reading the template and/or its metadata. This is the last method that is called by the TemplateCache for a template source, except that Object.equals(Object) is might called later too. TemplateCache ensures 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.

getBaseDirectory

public File getBaseDirectory()

Returns the base directory in which the templates are searched. This comes from the constructor argument, but it's possibly a canonicalized version of that.

Since:

2.3.21

setEmulateCaseSensitiveFileSystem

public void setEmulateCaseSensitiveFileSystem(boolean nameCaseChecked)

Intended for development only, checks if the template name matches the case (upper VS lower case letters) of the actual file name, and if it doesn't, it emulates a file-not-found even if the file system is case insensitive. This is useful when developing application on Windows, which will be later installed on Linux, OS X, etc. This check can be resource intensive, as to check the file name the directories involved, up to the getBaseDirectory() directory, must be listed. Positive results (matching case) will be cached without expiration time.

The default in FileTemplateLoader is false, but subclasses may change they by overriding getEmulateCaseSensitiveFileSystemDefault().

Since:

2.3.23

getEmulateCaseSensitiveFileSystem

public boolean getEmulateCaseSensitiveFileSystem()

Getter pair of setEmulateCaseSensitiveFileSystem(boolean).

Since:

2.3.23

getEmulateCaseSensitiveFileSystemDefault

protected boolean getEmulateCaseSensitiveFileSystemDefault()

Returns the default of getEmulateCaseSensitiveFileSystem(). In FileTemplateLoader it's false, unless the SYSTEM_PROPERTY_NAME_EMULATE_CASE_SENSITIVE_FILE_SYSTEM system property was set to true, but this can be overridden here in custom subclasses. For example, if your environment defines something like developer mode, you may want to override this to return true on Windows.

Since:

2.3.23

toString

public String toString()

Show class name and some details that are useful in template-not-found errors.

Overrides:

toString in class Object

Since:

2.3.21