org.springframework.beans.factory.config.YamlPropertiesFactoryBean Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* 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.beans.factory.config;
import java.util.Properties;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.CollectionFactory;
import org.springframework.lang.Nullable;
/**
* Factory for {@link java.util.Properties} that reads from a YAML source,
* exposing a flat structure of String property values.
*
* YAML is a nice human-readable format for configuration, and it has some
* useful hierarchical properties. It's more or less a superset of JSON, so it
* has a lot of similar features.
*
*
Note: All exposed values are of type {@code String} for access through
* the common {@link Properties#getProperty} method (e.g. in configuration property
* resolution through {@link PropertyResourceConfigurer#setProperties(Properties)}).
* If this is not desirable, use {@link YamlMapFactoryBean} instead.
*
*
The Properties created by this factory have nested paths for hierarchical
* objects, so for instance this YAML
*
*
* environments:
* dev:
* url: http://dev.bar.com
* name: Developer Setup
* prod:
* url: http://foo.bar.com
* name: My Cool App
*
*
* is transformed into these properties:
*
*
* environments.dev.url=http://dev.bar.com
* environments.dev.name=Developer Setup
* environments.prod.url=http://foo.bar.com
* environments.prod.name=My Cool App
*
*
* Lists are split as property keys with [] dereferencers, for
* example this YAML:
*
*
* servers:
* - dev.bar.com
* - foo.bar.com
*
*
* becomes properties like this:
*
*
* servers[0]=dev.bar.com
* servers[1]=foo.bar.com
*
*
* Requires SnakeYAML 1.18 or higher, as of Spring Framework 5.0.6.
*
* @author Dave Syer
* @author Stephane Nicoll
* @author Juergen Hoeller
* @since 4.1
*/
public class YamlPropertiesFactoryBean extends YamlProcessor implements FactoryBean, InitializingBean {
private boolean singleton = true;
@Nullable
private Properties properties;
/**
* Set if a singleton should be created, or a new object on each request
* otherwise. Default is {@code true} (a singleton).
*/
public void setSingleton(boolean singleton) {
this.singleton = singleton;
}
@Override
public boolean isSingleton() {
return this.singleton;
}
@Override
public void afterPropertiesSet() {
if (isSingleton()) {
this.properties = createProperties();
}
}
@Override
@Nullable
public Properties getObject() {
return (this.properties != null ? this.properties : createProperties());
}
@Override
public Class getObjectType() {
return Properties.class;
}
/**
* Template method that subclasses may override to construct the object
* returned by this factory. The default implementation returns a
* properties with the content of all resources.
* Invoked lazily the first time {@link #getObject()} is invoked in
* case of a shared singleton; else, on each {@link #getObject()} call.
* @return the object returned by this factory
* @see #process(MatchCallback) ()
*/
protected Properties createProperties() {
Properties result = CollectionFactory.createStringAdaptingProperties();
process((properties, map) -> result.putAll(properties));
return result;
}
}