/*
* 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.
*/
package freemarker.cache;
import java.io.
Reader;
import java.io.
StringReader;
import java.util.
HashMap;
import java.util.
Map;
import freemarker.template.utility.
StringUtil;
/**
* A {@link TemplateLoader} that uses a {@link Map} with {@link String}-s as its source of
* templates.
*
* <p>In most case the regular way of loading templates from files will be fine.
* However, there can be situations where you don't want to or can't load a
* template from a file, e.g. if you have to deploy a single jar for
* JavaWebStart or if they are contained within a database.
* A single template can be created manually
* e.g.
* <pre>
* String templateStr="Hello ${user}";
* Template t = new Template("name", new StringReader(templateStr),
* new Configuration());
* </pre>
* <p>If, however, you want to create templates from strings which import other
* templates this method doesn't work.
*
* <p>In that case you can create a StringTemplateLoader and add each template to
* it:
* <pre>
* StringTemplateLoader stringLoader = new StringTemplateLoader();
* stringLoader.putTemplate("greetTemplate", "<#macro greet>Hello</#macro>");
* stringLoader.putTemplate("myTemplate", "<#include \"greetTemplate\"><@greet/> World!");
* </pre>
* <p>Then you tell your Configuration object to use it:
* <pre>
* cfg.setTemplateLoader(stringLoader);
* </pre>
* <p>After that you should be able to use the templates as usual. Often you will
* want to combine a <tt>StringTemplateLoader</tt> with another loader. You can
* do so using a {@link freemarker.cache.MultiTemplateLoader}.
*/
public class
StringTemplateLoader implements
TemplateLoader {
private final
Map<
String,
StringTemplateSource>
templates = new
HashMap<
String,
StringTemplateSource>();
/**
* Puts a template into the loader. A call to this method is identical to
* the call to the three-arg {@link #putTemplate(String, String, long)}
* passing <tt>System.currentTimeMillis()</tt> as the third argument.
*
* <p>Note that this method is not thread safe! Don't call it after FreeMarker has started using this template
* loader.
*
* @param name the name of the template.
* @param templateContent the source code of the template.
*/
public void
putTemplate(
String name,
String templateContent) {
putTemplate(
name,
templateContent,
System.
currentTimeMillis());
}
/**
* Puts a template into the loader. The name can contain slashes to denote
* logical directory structure, but must not start with a slash. If the
* method is called multiple times for the same name and with different
* last modified time, the configuration's template cache will reload the
* template according to its own refresh settings (note that if the refresh
* is disabled in the template cache, the template will not be reloaded).
* Also, since the cache uses lastModified to trigger reloads, calling the
* method with different source and identical timestamp won't trigger
* reloading.
*
* <p>Note that this method is not thread safe! Don't call it after FreeMarker has started using this template
* loader.
*
* @param name the name of the template.
* @param templateContent the source code of the template.
* @param lastModified the time of last modification of the template in
* terms of <tt>System.currentTimeMillis()</tt>
*/
public void
putTemplate(
String name,
String templateContent, long
lastModified) {
templates.
put(
name, new
StringTemplateSource(
name,
templateContent,
lastModified));
}
/**
* Removes the template with the specified name if it was added earlier.
*
* <p>Note that this method is not thread safe! Don't call it after FreeMarker has started using this template
* loader.
*
* @param name Exactly the key with which the template was added.
*
* @return Whether a template was found with the given key (and hence was removed now)
*
* @since 2.3.24
*/
public boolean
removeTemplate(
String name) {
return
templates.
remove(
name) != null;
}
public void
closeTemplateSource(
Object templateSource) {
}
public
Object findTemplateSource(
String name) {
return
templates.
get(
name);
}
public long
getLastModified(
Object templateSource) {
return ((
StringTemplateSource)
templateSource).
lastModified;
}
public
Reader getReader(
Object templateSource,
String encoding) {
return new
StringReader(((
StringTemplateSource)
templateSource).
templateContent);
}
private static class
StringTemplateSource {
private final
String name;
private final
String templateContent;
private final long
lastModified;
StringTemplateSource(
String name,
String templateContent, long
lastModified) {
if (
name == null) {
throw new
IllegalArgumentException("name == null");
}
if (
templateContent == null) {
throw new
IllegalArgumentException("source == null");
}
if (
lastModified < -1L) {
throw new
IllegalArgumentException("lastModified < -1L");
}
this.
name =
name;
this.
templateContent =
templateContent;
this.
lastModified =
lastModified;
}
@
Override
public int
hashCode() {
final int
prime = 31;
int
result = 1;
result =
prime *
result + ((
name == null) ? 0 :
name.
hashCode());
return
result;
}
@
Override
public boolean
equals(
Object obj) {
if (this ==
obj)
return true;
if (
obj == null)
return false;
if (
getClass() !=
obj.
getClass())
return false;
StringTemplateSource other = (
StringTemplateSource)
obj;
if (
name == null) {
if (
other.
name != null)
return false;
} else if (!
name.
equals(
other.
name))
return false;
return true;
}
@
Override
public
String toString() {
return
name;
}
}
/**
* Show class name and some details that are useful in template-not-found errors.
*
* @since 2.3.21
*/
@
Override
public
String toString() {
StringBuilder sb = new
StringBuilder();
sb.
append(
TemplateLoaderUtils.
getClassNameForToString(this));
sb.
append("(Map { ");
int
cnt = 0;
for (
String name :
templates.
keySet()) {
cnt++;
if (
cnt != 1) {
sb.
append(", ");
}
if (
cnt > 10) {
sb.
append("...");
break;
}
sb.
append(
StringUtil.
jQuote(
name));
sb.
append("=...");
}
if (
cnt != 0) {
sb.
append(' ');
}
sb.
append("})");
return
sb.
toString();
}
}