如何讀取.properties文件配置的兩種方法

第一種方法：

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

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;
import org.springframework.util.DefaultPropertiesPersister;
import org.springframework.util.PropertiesPersister;

/**
 * Properties Util函數.
 * 
 * @author uniz
 */
public class PropertiesUtils {

	private static final String DEFAULT_ENCODING = "UTF-8";

	private static Logger logger = LoggerFactory.getLogger(PropertiesUtils.class);

	private static PropertiesPersister propertiesPersister = new DefaultPropertiesPersister();
	private static ResourceLoader resourceLoader = new DefaultResourceLoader();

	/**
	 * 載入多個properties文件, 相同的屬性在最後載入的文件中的值將會覆蓋之前的載入.
	 * 文件路徑使用Spring Resource格式, 文件編碼使用UTF-8.
	 * 
	 * @see org.springframework.beans.factory.config.PropertyPlaceholderConfigurer
	 */
	public static Properties loadProperties(String... resourcesPaths) throws IOException {
		Properties props = new Properties();

		for (String location : resourcesPaths) {

			logger.debug("Loading properties file from:" + location);

			InputStream is = null;
			try {
				Resource resource = resourceLoader.getResource(location);
				is = resource.getInputStream();
				propertiesPersister.load(props, new InputStreamReader(is, DEFAULT_ENCODING));
			} catch (IOException ex) {
				logger.info("Could not load properties from classpath:" + location + ": " + ex.getMessage());
			} finally {
				if (is != null) {
					is.close();
				}
			}
		}
		return props;
	}
	
	public static String getDataVal(String key) {
		try {
			Properties properties = PropertiesUtils.loadProperties("/config/config.properties");
			if (properties == null) return "";
		
			return new String((properties.getProperty(key))
					.getBytes("ISO8859_1"), "utf-8");
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
}

第二種方法：

package com.cl.common.utils;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Properties;

import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.util.DefaultPropertiesPersister;

public class PropertiesUtils {
	public PropertiesUtils(){
	}
	private static Properties props = new Properties();
	
	public static void loadProperties(String path){
//		InputStream is = null;
//		Resource rs = new DefaultResourceLoader().getResource(path);
//		try {
//			is = rs.getInputStream();
//			new DefaultPropertiesPersister().load(props, new InputStreamReader(is,"UTF-8"));
//		} catch (UnsupportedEncodingException e) {
//			e.printStackTrace();
//		} catch (IOException e) {
//			e.printStackTrace();
//		}
		try {
			props.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("/config/application.properties"));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	public static String getVal(String key){
		return props.getProperty(key);
	}
}