/*
* Copyright 2002-2010 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
*
* 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.springframework.core.io;
import java.beans.PropertyEditorSupport;
import java.io.IOException;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.util.SystemPropertyUtils;
/**
* {@link java.beans.PropertyEditor Editor} for {@link Resource}
* descriptors, to automatically convert <code>String</code> locations
* e.g. <code>"file:C:/myfile.txt"</code> or
* <code>"classpath:myfile.txt"</code>) to <code>Resource</code>
* properties instead of using a <code>String</code> location property.
*
* <p>The path may contain <code>${...}</code> placeholders,
* to be resolved as system properties: e.g. <code>${user.dir}</code>.
* Unresolvable placeholder are ignored by default.
*
* <p>Delegates to a {@link ResourceLoader} to do the heavy lifting,
* by default using a {@link DefaultResourceLoader}.
*
* @author Juergen Hoeller
* @author Dave Syer
* @since 28.12.2003
* @see Resource
* @see ResourceLoader
* @see DefaultResourceLoader
* @see org.springframework.util.SystemPropertyUtils#resolvePlaceholders
* @see System#getProperty(String)
*/
public class ResourceEditor extends PropertyEditorSupport {
private final ResourceLoader resourceLoader;
private final boolean ignoreUnresolvablePlaceholders;
/**
* Create a new instance of the {@link ResourceEditor} class
* using a {@link DefaultResourceLoader}.
*/
public ResourceEditor() {
this(new DefaultResourceLoader());
}
/**
* Create a new instance of the {@link ResourceEditor} class
* using the given {@link ResourceLoader}.
* @param resourceLoader the <code>ResourceLoader</code> to use
*/
public ResourceEditor(ResourceLoader resourceLoader) {
this(resourceLoader, true);
}
/**
* Create a new instance of the {@link ResourceEditor} class
* using the given {@link ResourceLoader}.
* @param resourceLoader the <code>ResourceLoader</code> to use
* @param ignoreUnresolvablePlaceholders whether to ignore unresolvable placeholders
* if no corresponding system property could be found
*/
public ResourceEditor(ResourceLoader resourceLoader, boolean ignoreUnresolvablePlaceholders) {
Assert.notNull(resourceLoader, "ResourceLoader must not be null");
this.resourceLoader = resourceLoader;
this.ignoreUnresolvablePlaceholders = ignoreUnresolvablePlaceholders;
}
@Override
public void setAsText(String text) {
if (StringUtils.hasText(text)) {
String locationToUse = resolvePath(text).trim();
setValue(this.resourceLoader.getResource(locationToUse));
}
else {
setValue(null);
}
}
/**
* Resolve the given path, replacing placeholders with
* corresponding system property values if necessary.
* @param path the original file path
* @return the resolved file path
* @see org.springframework.util.SystemPropertyUtils#resolvePlaceholders
*/
protected String resolvePath(String path) {
return SystemPropertyUtils.resolvePlaceholders(path, this.ignoreUnresolvablePlaceholders);
}
@Override
public String getAsText() {
Resource value = (Resource) getValue();
try {
// Try to determine URL for resource.
return (value != null ? value.getURL().toExternalForm() : "");
}
catch (IOException ex) {
// Couldn't determine resource URL - return null to indicate
// that there is no appropriate text representation.
return null;
}
}
}
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