Spring自定义PropertyPlaceholderConfigurer

1. CustomPropertyConfigurer.java

package propertyconfig;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Map.Entry;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
import org.springframework.util.PropertyPlaceholderHelper;

public class CustomPropertyConfigurer extends PropertyPlaceholderConfigurer{
	private static Map<String,String> properties = new HashMap<String,String>();
	protected void processProperties(
			ConfigurableListableBeanFactory beanFactoryToProcess,
			Properties props) throws BeansException {
		// cache the properties
		PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper(
				DEFAULT_PLACEHOLDER_PREFIX, DEFAULT_PLACEHOLDER_SUFFIX, DEFAULT_VALUE_SEPARATOR, false);
		for(Entry<Object,Object> entry:props.entrySet()){
			String stringKey = String.valueOf(entry.getKey());
			String stringValue = String.valueOf(entry.getValue());
			stringValue = helper.replacePlaceholders(stringValue, props);
			properties.put(stringKey, stringValue);
		}
		super.processProperties(beanFactoryToProcess, props);
	}
	
	public static Map<String, String> getProperties() {
		return properties;
	}
	
	public static String getProperty(String key){
		return properties.get(key);
	}
}

 2. applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"  
    xmlns:aop="http://www.springframework.org/schema/aop"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd   
    http://www.springframework.org/schema/aop  
    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"  
    default-lazy-init="true" default-autowire="byName" default-init-method="" default-destroy-method="">  
    <bean id="propertyConfigurer"  class="propertyconfig.CustomPropertyConfigurer">  
        <property name="locations">  
            <list>  
                <value>classpath:propertyconfig/project.properties</value>  
            </list>  
        </property>  
    </bean>  
</beans>  

 3. project.properties

site=iteye
blog=antlove
url=${site}/${blog}

 4. Main.java测试类

package propertyconfig;
import java.util.Map;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
	public static void main(String[] args) {
		new ClassPathXmlApplicationContext("propertyconfig/applicationContext.xml");
		
		Map<String,String> properties = CustomPropertyConfigurer.getProperties();
		
		System.out.println(properties);
	}
}