org.springframework.core.io.ResourceEditor Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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.core.io;
import java.beans.PropertyEditorSupport;
import java.io.IOException;
import org.springframework.core.env.PropertyResolver;
import org.springframework.core.env.StandardEnvironment;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* {@link java.beans.PropertyEditor Editor} for {@link Resource}
* descriptors, to automatically convert {@code String} locations
* e.g. {@code file:C:/myfile.txt} or {@code classpath:myfile.txt} to
* {@code Resource} properties instead of using a {@code String} location property.
*
* The path may contain {@code ${...}} placeholders, to be
* resolved as {@link org.springframework.core.env.Environment} properties:
* e.g. {@code ${user.dir}}. Unresolvable placeholders are ignored by default.
*
*
Delegates to a {@link ResourceLoader} to do the heavy lifting,
* by default using a {@link DefaultResourceLoader}.
*
* @author Juergen Hoeller
* @author Dave Syer
* @author Chris Beams
* @since 28.12.2003
* @see Resource
* @see ResourceLoader
* @see DefaultResourceLoader
* @see PropertyResolver#resolvePlaceholders
*/
public class ResourceEditor extends PropertyEditorSupport {
private final ResourceLoader resourceLoader;
@Nullable
private PropertyResolver propertyResolver;
private final boolean ignoreUnresolvablePlaceholders;
/**
* Create a new instance of the {@link ResourceEditor} class
* using a {@link DefaultResourceLoader} and {@link StandardEnvironment}.
*/
public ResourceEditor() {
this(new DefaultResourceLoader(), null);
}
/**
* Create a new instance of the {@link ResourceEditor} class
* using the given {@link ResourceLoader} and {@link PropertyResolver}.
* @param resourceLoader the {@code ResourceLoader} to use
* @param propertyResolver the {@code PropertyResolver} to use
*/
public ResourceEditor(ResourceLoader resourceLoader, @Nullable PropertyResolver propertyResolver) {
this(resourceLoader, propertyResolver, true);
}
/**
* Create a new instance of the {@link ResourceEditor} class
* using the given {@link ResourceLoader}.
* @param resourceLoader the {@code ResourceLoader} to use
* @param propertyResolver the {@code PropertyResolver} to use
* @param ignoreUnresolvablePlaceholders whether to ignore unresolvable placeholders
* if no corresponding property could be found in the given {@code propertyResolver}
*/
public ResourceEditor(ResourceLoader resourceLoader, @Nullable PropertyResolver propertyResolver,
boolean ignoreUnresolvablePlaceholders) {
Assert.notNull(resourceLoader, "ResourceLoader must not be null");
this.resourceLoader = resourceLoader;
this.propertyResolver = propertyResolver;
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
* property values from the {@code environment} if necessary.
* @param path the original file path
* @return the resolved file path
* @see PropertyResolver#resolvePlaceholders
* @see PropertyResolver#resolveRequiredPlaceholders
*/
protected String resolvePath(String path) {
if (this.propertyResolver == null) {
this.propertyResolver = new StandardEnvironment();
}
return (this.ignoreUnresolvablePlaceholders ? this.propertyResolver.resolvePlaceholders(path) :
this.propertyResolver.resolveRequiredPlaceholders(path));
}
@Override
@Nullable
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;
}
}
}