java加载配置文件properties中的数据

在类路径下存在conf/mail.properties文件

内容：

host=test

加载该文件：

工具类：

public class PropertiesUtils {    private static PropertiesUtils proper = new PropertiesUtils();

    private PropertiesUtils() {
    }

public static PropertiesUtils getInstance() {
return proper;
    }

public Map<String, String> load(String fileName) {
        HashMap map = new HashMap();
        if(StringUtils.isEmpty(fileName)) {
return map;
        } else {
            ResourceBundle bundle = ResourceBundle.getBundle(fileName);
            Iterator i$ = bundle.keySet().iterator();

            while(i$.hasNext()) {
                String key = (String)i$.next();
                map.put(key, bundle.getObject(key).toString());
            }

return map;
        }
    }
}

读取配置：

public class SystemContent {
private static Map<String,String> mailMap;

static{
mailMap=PropertiesUtils.getInstance().load("conf/mail");
}

public static final String host=mailMap.get("host");
}