/*
* Copyright 2002-2008 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.Collections;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanInitializationException;
/**
* Property resource configurer that overrides bean property values in an application
* context definition. It <i>pushes</i> values from a properties file into bean definitions.
*
* <p>Configuration lines are expected to be of the following form:
*
* <pre class="code">beanName.property=value</pre>
*
* Example properties file:
*
* <pre class="code">dataSource.driverClassName=com.mysql.jdbc.Driver
* dataSource.url=jdbc:mysql:mydb</pre>
*
* In contrast to PropertyPlaceholderConfigurer, the original definition can have default
* values or no values at all for such bean properties. If an overriding properties file does
* not have an entry for a certain bean property, the default context definition is used.
*
* <p>Note that the context definition <i>is not</i> aware of being overridden;
* so this is not immediately obvious when looking at the XML definition file.
* Furthermore, note that specified override values are always <i>literal</i> values;
* they are not translated into bean references. This also applies when the original
* value in the XML bean definition specifies a bean reference.
*
* <p>In case of multiple PropertyOverrideConfigurers that define different values for
* the same bean property, the <i>last</i> one will win (due to the overriding mechanism).
*
* <p>Property values can be converted after reading them in, through overriding
* the <code>convertPropertyValue</code> method. For example, encrypted values
* can be detected and decrypted accordingly before processing them.
*
* @author Juergen Hoeller
* @author Rod Johnson
* @since 12.03.2003
* @see #convertPropertyValue
* @see PropertyPlaceholderConfigurer
*/
public class PropertyOverrideConfigurer extends PropertyResourceConfigurer {
public static final String DEFAULT_BEAN_NAME_SEPARATOR = ".";
private String beanNameSeparator = DEFAULT_BEAN_NAME_SEPARATOR;
private boolean ignoreInvalidKeys = false;
/** Contains names of beans that have overrides */
private Set beanNames = Collections.synchronizedSet(new HashSet());
/**
* Set the separator to expect between bean name and property path.
* Default is a dot (".").
*/
public void setBeanNameSeparator(String beanNameSeparator) {
this.beanNameSeparator = beanNameSeparator;
}
/**
* Set whether to ignore invalid keys. Default is "false".
* <p>If you ignore invalid keys, keys that do not follow the
* 'beanName.property' format will just be logged as warning.
* This allows to have arbitrary other keys in a properties file.
*/
public void setIgnoreInvalidKeys(boolean ignoreInvalidKeys) {
this.ignoreInvalidKeys = ignoreInvalidKeys;
}
protected void processProperties(ConfigurableListableBeanFactory beanFactory, Properties props)
throws BeansException {
for (Enumeration names = props.propertyNames(); names.hasMoreElements();) {
String key = (String) names.nextElement();
try {
processKey(beanFactory, key, props.getProperty(key));
}
catch (BeansException ex) {
String msg = "Could not process key '" + key + "' in PropertyOverrideConfigurer";
if (!this.ignoreInvalidKeys) {
throw new BeanInitializationException(msg, ex);
}
if (logger.isDebugEnabled()) {
logger.debug(msg, ex);
}
}
}
}
/**
* Process the given key as 'beanName.property' entry.
*/
protected void processKey(ConfigurableListableBeanFactory factory, String key, String value)
throws BeansException {
int separatorIndex = key.indexOf(this.beanNameSeparator);
if (separatorIndex == -1) {
throw new BeanInitializationException("Invalid key '" + key +
"': expected 'beanName" + this.beanNameSeparator + "property'");
}
String beanName = key.substring(0, separatorIndex);
String beanProperty = key.substring(separatorIndex+1);
this.beanNames.add(beanName);
applyPropertyValue(factory, beanName, beanProperty, value);
if (logger.isDebugEnabled()) {
logger.debug("Property '" + key + "' set to value [" + value + "]");
}
}
/**
* Apply the given property value to the corresponding bean.
*/
protected void applyPropertyValue(
ConfigurableListableBeanFactory factory, String beanName, String property, String value) {
BeanDefinition bd = factory.getBeanDefinition(beanName);
while (bd.getOriginatingBeanDefinition() != null) {
bd = bd.getOriginatingBeanDefinition();
}
bd.getPropertyValues().addPropertyValue(property, value);
}
/**
* Were there overrides for this bean?
* Only valid after processing has occurred at least once.
* @param beanName name of the bean to query status for
* @return whether there were property overrides for
* the named bean
*/
public boolean hasPropertyOverridesFor(String beanName) {
return this.beanNames.contains(beanName);
}
}