org.springframework.boot.context.properties.bind.PropertySourcesPlaceholdersResolver Maven / Gradle / Ivy
/*
* Copyright 2012-2018 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.context.properties.bind;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.PropertySource;
import org.springframework.core.env.PropertySources;
import org.springframework.util.Assert;
import org.springframework.util.PropertyPlaceholderHelper;
import org.springframework.util.SystemPropertyUtils;
/**
* {@link PlaceholdersResolver} to resolve placeholders from {@link PropertySources}.
*
* @author Phillip Webb
* @author Madhura Bhave
* @since 2.0.0
*/
public class PropertySourcesPlaceholdersResolver implements PlaceholdersResolver {
private final Iterable> sources;
private final PropertyPlaceholderHelper helper;
public PropertySourcesPlaceholdersResolver(Environment environment) {
this(getSources(environment), null);
}
public PropertySourcesPlaceholdersResolver(Iterable> sources) {
this(sources, null);
}
public PropertySourcesPlaceholdersResolver(Iterable> sources,
PropertyPlaceholderHelper helper) {
this.sources = sources;
this.helper = (helper != null) ? helper
: new PropertyPlaceholderHelper(SystemPropertyUtils.PLACEHOLDER_PREFIX,
SystemPropertyUtils.PLACEHOLDER_SUFFIX,
SystemPropertyUtils.VALUE_SEPARATOR, true);
}
@Override
public Object resolvePlaceholders(Object value) {
if (value != null && value instanceof String) {
return this.helper.replacePlaceholders((String) value,
this::resolvePlaceholder);
}
return value;
}
protected String resolvePlaceholder(String placeholder) {
if (this.sources != null) {
for (PropertySource source : this.sources) {
Object value = source.getProperty(placeholder);
if (value != null) {
return String.valueOf(value);
}
}
}
return null;
}
private static PropertySources getSources(Environment environment) {
Assert.notNull(environment, "Environment must not be null");
Assert.isInstanceOf(ConfigurableEnvironment.class, environment,
"Environment must be a ConfigurableEnvironment");
return ((ConfigurableEnvironment) environment).getPropertySources();
}
}