org.thymeleaf.spring4.templateresource.SpringResourceTemplateResource Maven / Gradle / Ivy
/*
* =============================================================================
*
* Copyright (c) 2011-2016, The THYMELEAF team (http://www.thymeleaf.org)
*
* 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
*
* 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 org.thymeleaf.spring4.templateresource;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.Resource;
import org.thymeleaf.templateresource.ITemplateResource;
import org.thymeleaf.util.StringUtils;
import org.thymeleaf.util.Validate;
/**
*
* Implementation of {@link ITemplateResource} that resolves
* resources by delegating on Spring's resource resolution mechanism, implemented by the
* {@link org.springframework.core.io.ResourceLoader} interface.
*
*
* This resource resolver accesses the Spring resource resolution mechanism by means of
* calls to {@link ApplicationContext#getResource(String)}.
*
*
* @author Daniel Fernández
*
* @since 3.0.0
*
*/
public final class SpringResourceTemplateResource implements ITemplateResource {
private final Resource resource;
private final String characterEncoding;
public SpringResourceTemplateResource(
final ApplicationContext applicationContext, final String location, final String characterEncoding) {
super();
Validate.notNull(applicationContext, "Application Context cannot be null");
Validate.notEmpty(location, "Resource Location cannot be null or empty");
// Character encoding CAN be null (system default will be used)
this.resource = applicationContext.getResource(location);
this.characterEncoding = characterEncoding;
}
public SpringResourceTemplateResource(
final Resource resource, final String characterEncoding) {
super();
Validate.notNull(resource, "Resource cannot be null");
// Character encoding CAN be null (system default will be used)
this.resource = resource;
this.characterEncoding = characterEncoding;
}
public String getDescription() {
return this.resource.getDescription();
}
public String getBaseName() {
return computeBaseName(this.resource.getFilename());
}
public boolean exists() {
return this.resource.exists();
}
public Reader reader() throws IOException {
// Will never return null, but an IOException if not found
final InputStream inputStream = this.resource.getInputStream();
if (!StringUtils.isEmptyOrWhitespace(this.characterEncoding)) {
return new BufferedReader(new InputStreamReader(new BufferedInputStream(inputStream), this.characterEncoding));
}
return new BufferedReader(new InputStreamReader(new BufferedInputStream(inputStream)));
}
public ITemplateResource relative(final String relativeLocation) {
final Resource relativeResource;
try {
relativeResource = this.resource.createRelative(relativeLocation);
} catch (final IOException e) {
// Given we have delegated the createRelative(...) mechanism to Spring, it's better if we don't do
// any assumptions on what this IOException means and simply return a resource object that returns
// no reader and exists() == false.
return new SpringResourceInvalidRelativeTemplateResource(getDescription(), relativeLocation, e);
}
return new SpringResourceTemplateResource(relativeResource, this.characterEncoding);
}
static String computeBaseName(final String path) {
if (path == null || path.length() == 0) {
return null;
}
// First remove a trailing '/' if it exists
final String basePath = (path.charAt(path.length() - 1) == '/'? path.substring(0,path.length() - 1) : path);
final int slashPos = basePath.lastIndexOf('/');
if (slashPos != -1) {
final int dotPos = basePath.lastIndexOf('.');
if (dotPos != -1 && dotPos > slashPos + 1) {
return basePath.substring(slashPos + 1, dotPos);
}
return basePath.substring(slashPos + 1);
} else {
final int dotPos = basePath.lastIndexOf('.');
if (dotPos != -1) {
return basePath.substring(0, dotPos);
}
}
return (basePath.length() > 0? basePath : null);
}
private static final class SpringResourceInvalidRelativeTemplateResource implements ITemplateResource {
private final String originalResourceDescription;
private final String relativeLocation;
private final IOException ioException;
SpringResourceInvalidRelativeTemplateResource(
final String originalResourceDescription,
final String relativeLocation,
final IOException ioException) {
super();
this.originalResourceDescription = originalResourceDescription;
this.relativeLocation = relativeLocation;
this.ioException = ioException;
}
@Override
public String getDescription() {
return "Invalid relative resource for relative location \"" + this.relativeLocation +
"\" and original resource " + this.originalResourceDescription + ": " + this.ioException.getMessage();
}
@Override
public String getBaseName() {
return "Invalid relative resource for relative location \"" + this.relativeLocation +
"\" and original resource " + this.originalResourceDescription + ": " + this.ioException.getMessage();
}
@Override
public boolean exists() {
return false;
}
@Override
public Reader reader() throws IOException {
throw new IOException("Invalid relative resource", this.ioException);
}
@Override
public ITemplateResource relative(final String relativeLocation) {
return this;
}
@Override
public String toString() {
return getDescription();
}
}
}