org.springframework.boot.autoconfigure.template.PathBasedTemplateAvailabilityProvider Maven / Gradle / Ivy
/*
* Copyright 2012-2019 the original author or authors.
*
* Licensed 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
*
* https://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 org.springframework.boot.autoconfigure.template;
import java.util.List;
import org.springframework.boot.context.properties.bind.Binder;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ResourceLoader;
import org.springframework.util.ClassUtils;
/**
* Abstract base class for {@link TemplateAvailabilityProvider} implementations that find
* templates from paths.
*
* @author Andy Wilkinson
* @author Phillip Webb
* @author Madhura Bhave
* @since 1.4.6
*/
public abstract class PathBasedTemplateAvailabilityProvider implements TemplateAvailabilityProvider {
private final String className;
private final Class propertiesClass;
private final String propertyPrefix;
@SuppressWarnings("unchecked")
public PathBasedTemplateAvailabilityProvider(String className,
Class propertiesClass, String propertyPrefix) {
this.className = className;
this.propertiesClass = (Class) propertiesClass;
this.propertyPrefix = propertyPrefix;
}
@Override
public boolean isTemplateAvailable(String view, Environment environment, ClassLoader classLoader,
ResourceLoader resourceLoader) {
if (ClassUtils.isPresent(this.className, classLoader)) {
Binder binder = Binder.get(environment);
TemplateAvailabilityProperties properties = binder.bindOrCreate(this.propertyPrefix, this.propertiesClass);
return isTemplateAvailable(view, resourceLoader, properties);
}
return false;
}
private boolean isTemplateAvailable(String view, ResourceLoader resourceLoader,
TemplateAvailabilityProperties properties) {
String location = properties.getPrefix() + view + properties.getSuffix();
for (String path : properties.getLoaderPath()) {
if (resourceLoader.getResource(path + location).exists()) {
return true;
}
}
return false;
}
protected abstract static class TemplateAvailabilityProperties {
private String prefix;
private String suffix;
protected TemplateAvailabilityProperties(String prefix, String suffix) {
this.prefix = prefix;
this.suffix = suffix;
}
protected abstract List getLoaderPath();
public String getPrefix() {
return this.prefix;
}
public void setPrefix(String prefix) {
this.prefix = prefix;
}
public String getSuffix() {
return this.suffix;
}
public void setSuffix(String suffix) {
this.suffix = suffix;
}
}
}