org.springframework.beans.factory.config.PropertiesFactoryBean 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.beans.factory.config;
import java.io.IOException;
import java.util.Properties;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.support.PropertiesLoaderSupport;
import org.springframework.lang.Nullable;
/**
* Allows for making a properties file from a classpath location available
* as Properties instance in a bean factory. Can be used to populate
* any bean property of type Properties via a bean reference.
*
* Supports loading from a properties file and/or setting local properties
* on this FactoryBean. The created Properties instance will be merged from
* loaded and local values. If neither a location nor local properties are set,
* an exception will be thrown on initialization.
*
*
Can create a singleton or a new object on each request.
* Default is a singleton.
*
* @author Juergen Hoeller
* @see #setLocation
* @see #setProperties
* @see #setLocalOverride
* @see java.util.Properties
*/
public class PropertiesFactoryBean extends PropertiesLoaderSupport
implements FactoryBean, InitializingBean {
private boolean singleton = true;
@Nullable
private Properties singletonInstance;
/**
* Set whether a shared 'singleton' Properties instance should be
* created, or rather a new Properties instance on each request.
* Default is "true" (a shared singleton).
*/
public final void setSingleton(boolean singleton) {
this.singleton = singleton;
}
@Override
public final boolean isSingleton() {
return this.singleton;
}
@Override
public final void afterPropertiesSet() throws IOException {
if (this.singleton) {
this.singletonInstance = createProperties();
}
}
@Override
@Nullable
public final Properties getObject() throws IOException {
if (this.singleton) {
return this.singletonInstance;
}
else {
return 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 the
* plain merged Properties instance.
* Invoked on initialization of this FactoryBean in case of a
* shared singleton; else, on each {@link #getObject()} call.
* @return the object returned by this factory
* @throws IOException if an exception occurred during properties loading
* @see #mergeProperties()
*/
protected Properties createProperties() throws IOException {
return mergeProperties();
}
}