View difference between Paste ID: VeaJEQb2 and w8P3PEY2

 package ru.nsu.ccfit.batalov.task1;
 
 import ru.nsu.ccfit.batalov.task1.command.Command;
 import ru.nsu.ccfit.batalov.task1.exception.BadArgumentsException;
 import ru.nsu.ccfit.batalov.task1.exception.UnknownCommandException;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.HashMap;
 import java.util.Properties;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
  * Creates classes which implemented calculating.
  * @author batalov
  */
 public class Factory {
     private static final Logger LOGGER = Logger.getLogger(Calculator.class.getName());
     private HashMap<String, Class> containerCommands = new HashMap<String, Class>(); //create informative name
     private Properties properties = new Properties();
 
     /**
      * Configures the factory.
      */
     private void readConfig() {
         InputStream in = null;
         try {
             in = getClass().getResourceAsStream("config.properties");
             properties.load(in);
             //you should close the stream
             //closing the stream should be performed using "finally" construct
         } catch (IOException e) {
             LOGGER.log(Level.SEVERE, "exception ", e);
         }
         finally {
             if (in != null){
                 try {
                     in.close();
                 } catch (IOException e) {
                     LOGGER.log(Level.SEVERE,"exception ",e);
                 }
             }
         }
     }
 
     /**
      * Instances new object.
      * @param obj {@link java.lang.Class}
      * @param arg {@link java.lang.String}
      * @return  {@link ru.nsu.ccfit.batalov.task1.command.Command}
      * @throws IllegalAccessException {@link java.lang.IllegalAccessException} if factory cant uses method or constructors for creates object.
      * @throws NoSuchMethodException  {@link java.lang.NoSuchMethodException} if factory cant finds method or constructors for creates object.
      * @throws InvocationTargetException {@link java.lang.reflect.InvocationTargetException} if cant call constructor.
      * @throws InstantiationException {@link java.lang.InstantiationException} if smth wrong with instantiation.
      */
     @SuppressWarnings("unchecked")
     private Command instance (Class obj , String[] arg) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException, InstantiationException {
         Class[] types = { String[].class };
         Constructor constructor = obj.getDeclaredConstructor(types);
         Object[] params = { arg};
         return (Command)constructor.newInstance(params);
     }
 
     /**
      * Creates command for calculating.
      * @param commandName {@link java.lang.String}
      * @param arg {@link java.lang.String}
      * @return {@link ru.nsu.ccfit.batalov.task1.command.Command}
      * @throws UnknownCommandException always when factory cant create class.
      */
     public Command get(String commandName, String[] arg) throws  UnknownCommandException{
         if (properties.isEmpty()) {
             this.readConfig();
         }
         Command command;
         try{
             if (containerCommands.containsKey(commandName)) {
                 Class obj = containerCommands.get(commandName);
                 command = instance(obj, arg);
             } else if (properties.containsKey(commandName)) {
                 Class obj = Class.forName(properties.getProperty(commandName));
                 command = instance(obj, arg);
                 containerCommands.put(commandName,obj);
             } else {
                 throw new UnknownCommandException();
             }
         }catch (NullPointerException e ){
             throw new UnknownCommandException();
         }catch (InvocationTargetException e){
             throw new BadArgumentsException();
         }catch (ClassNotFoundException e) {
             throw new UnknownCommandException();
         }catch (IllegalAccessException e) {
             throw new UnknownCommandException();
         }catch (NoSuchMethodException e) {
             throw new UnknownCommandException();
         }catch (InstantiationException e) {
             throw new UnknownCommandException();
         }
         return command;
     }
 }