In a project, we can write a class to read the properties.As following,

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

public class PropertyReader{
   private static Properties property = null;
  
   static{
      InputSteam stream = null;
      try{
        stream=PropertyReader.class.getResourceAsStream("/resource/properties.properties");
        property = new Properties();
        property.load(stream);
      }catch(IOException e){
          e.printStackTrace();
      }finally{
          if(stream != null){
             try{
                stream.close();
             }catch(IOException e){
                e.printStackTrace();
             }           
          }
      }
   }
   public static String getResource(String key){
     if(property == null){
       return null;// init error;
     }
     
     return property.getProperty(key);
   }
}