比較完善的解析Property

import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.util.Properties;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;




public class PropertiesUtils {
	private static Logger logger = LoggerFactory.getLogger(PropertiesUtils.class);
	private static ResourceLoader resourceLoader = new DefaultResourceLoader();
	private final Properties properties;
	public PropertiesUtils(String... resourcesPaths){
		properties = loadProperties(resourcesPaths);
	}
	public Properties getProperties(){
		return properties;
	}
	/**
	 * 取出Property
	 */
	private String getValue(String key){
		String systemProperties = System.getProperty(key);
		if(systemProperties!=null){
			return systemProperties;
		}
		return properties.getProperty(key);
	}
	/**
	 * 取出String類型的Property，如果都null則拋出異常
	 */
	public String getProperty(String key){
		String value = getValue(key);
		if(value == null){
			throw new NoSuchElementException();
		}
		return value;
	}
	/**
	 * 取出String類型的Property，如果都爲null則返回default值
	 */
	public String getProperty(String key,String defaultValue){
		String value = getValue(key);
		return value != null?value:defaultValue;
	}
	/**
	 * 取出Integer類型的Property，如果都爲null或內容出錯則拋出異常
	 */
	public Integer getInteger(String key){
		String value = getValue(key);
		if(value == null){
			throw new NoSuchElementException();
		}
		return Integer.valueOf(value);
	}
	/**
	 * 取出取出Integer類型的Property，如果都爲null則返回default值，如果內容出錯則拋出異常
	 */
	public Integer getInteger(String key,Integer defaultValue){
		String value = getValue(key);
		return value != null?Integer.valueOf(key):defaultValue;
	}
	/**
	 * 取出Double類型的Property，如果都爲null或內容出錯則拋出異常
	 */
	public Double getDouble(String key){
		String value = getValue(key);
		if(value == null){
			throw new NoSuchElementException();
		}
		return Double.valueOf(value);
	}
	/**
	 * 取出Double類型的Property，如果都爲null則返回default值，內容錯誤則拋出異常
	 */
	public Double getDouble(String key,Double defaultValue){
		String value = getValue(key);
		return value != null?Double.valueOf(value):defaultValue;
	}
	/**
	 * 取出boolean類型的Property，如果都爲null則拋出異常,如果內容不是true/false則返回false
	 */
	public Boolean getBoolean(String key){
		String value = getValue(key);
		if(value == null){
			throw new NoSuchElementException();
		}
		return Boolean.valueOf(value);
	}
	/**
	 * 取出boolean類型的Property，如果都爲null則返回default值,如果內容不是true/false則返回false
	 */
	public Boolean getBoolean(String key,Boolean defaultValue){
		String value = getValue(key);
		return value != null?Boolean.valueOf(value):defaultValue;
	}
	/**
	 * 載入多個文件，文件路徑使用 Spring Resource格式
	 */
	private Properties loadProperties(String... resourcePaths){
		Properties props = new Properties();
		for(String location:resourcePaths){
			logger.debug("Loading properties file from"+location);
			InputStream is = null;
			try{
				Resource resource = resourceLoader.getResource(location);
				is = resource.getInputStream();
				props.load(is);
			}catch (IOException ex){
				logger.info("colud not load Properties from path:"+location+","+ex.getMessage());
			}finally{
				IOUtils.closeQuietly(is);
			}
		}
		return props;
	}
}