Package freemarker.cache
Class ByteArrayTemplateLoader
java.lang.Object
freemarker.cache.ByteArrayTemplateLoader
- All Implemented Interfaces:
TemplateLoader
A
TemplateLoader
that uses a Map
with byte[]
as its source of templates. This is similar to
StringTemplateLoader
, but uses byte[]
instead of String
; see more details there.- Since:
- 2.3.24
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
closeTemplateSource(Object templateSource)
Closes the template source, releasing any resources held that are only required for reading the template and/or its metadata.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.long
getLastModified(Object templateSource)
Returns the time of last modification of the specified template source.Returns the character stream of a template represented by the specified template source.void
putTemplate(String name, byte[] templateContent)
Adds a template to this template loader; seeStringTemplateLoader.putTemplate(String, String)
for more.void
putTemplate(String name, byte[] templateContent, long lastModified)
Adds a template to this template loader; seeStringTemplateLoader.putTemplate(String, String, long)
for more.boolean
removeTemplate(String name)
Removes the template with the specified name if it was added earlier.; seeStringTemplateLoader.removeTemplate(String)
for more details.toString()
Show class name and some details that are useful in template-not-found errors.
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Constructor Details
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ByteArrayTemplateLoader
public ByteArrayTemplateLoader()
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Method Details
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putTemplate
Adds a template to this template loader; seeStringTemplateLoader.putTemplate(String, String)
for more. -
putTemplate
Adds a template to this template loader; seeStringTemplateLoader.putTemplate(String, String, long)
for more. -
removeTemplate
Removes the template with the specified name if it was added earlier.; seeStringTemplateLoader.removeTemplate(String)
for more details.- Since:
- 2.3.26
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closeTemplateSource
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 theTemplateCache
for a template source, except thatObject.equals(Object)
is might called later too.TemplateCache
ensures that this method will be called on every object that is returned fromTemplateLoader.findTemplateSource(String)
.- Specified by:
closeTemplateSource
in interfaceTemplateLoader
- Parameters:
templateSource
- the template source that should be closed.
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findTemplateSource
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 interfaceTemplateLoader
- Parameters:
name
- The name (template root directory relative path) of the template, already localized and normalized by thecache
. 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, by throwing an 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)
andTemplateLoader.getReader(Object, String)
, when those are called on the sameTemplateLoader
.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 theTemplateLoader
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 properObject.equals(Object)
andObject.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 fromObject.equals(Object)
when the compared template sources came from the sameTemplateLoader
instance. Also, it must not influence the equality if the source is open or closed (TemplateLoader.closeTemplateSource(Object)
).
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getLastModified
Description copied from interface:TemplateLoader
Returns the time of last modification of the specified template source. This method is called afterfindTemplateSource()
.- Specified by:
getLastModified
in interfaceTemplateLoader
- Parameters:
templateSource
- an object representing a template source (the template file), obtained through a prior call toTemplateLoader.findTemplateSource(String)
. This must be an object on whichTemplateLoader.closeTemplateSource(Object)
wasn't applied yet.- Returns:
- The time of last modification for the specified template source, or -1 if the time is not known. This
value meant to be milliseconds since the epoch, but in fact FreeMarker doesn't care what it means, it
only cares if it changes, in which case the template needs to be reloaded (even if the value has
decreased). -1 is not special in that regard either; if you keep returning it, FreeMarker won't
reload the template (as far as it's not evicted from the cache from some other
reason). Note that
Long.MIN_VALUE
is reserved for internal use.
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getReader
public Reader getReader(Object templateSource, String encoding) throws UnsupportedEncodingExceptionDescription 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 aReader
that reads the template from its beginning. Before this method is called for the second time (or later), its caller must close the previously returnedReader
, and it must not use it anymore. That is, this method is not required to support multiple concurrent readers for the same sourcetemplateSource
object.Typically, this method is called if the template is missing from the cache, or if after calling
TemplateLoader.findTemplateSource(String)
andTemplateLoader.getLastModified(Object)
it was determined that the cached copy of the template is stale. Then, if it turns out that theencoding
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 correctencoding
parameter value.Unlike
TemplateLoader.findTemplateSource(String)
, this method must not tolerate if the template is not found, and must throwIOException
in that case.- Specified by:
getReader
in interfaceTemplateLoader
- Parameters:
templateSource
- an object representing a template source, obtained through a prior call toTemplateLoader.findTemplateSource(String)
. This must be an object on whichTemplateLoader.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; notnull
. It's the responsibility of the caller (which isTemplateCache
usually) toclose()
it. TheReader
is not required to work after thetemplateSource
was closed (TemplateLoader.closeTemplateSource(Object)
). - Throws:
UnsupportedEncodingException
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toString
Show class name and some details that are useful in template-not-found errors.
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