[java design pattern] memo pattern

Step 1: Create the original class Original

public class Original {
	
	//The attribute value that needs to be saved
    private String value;

    //create memo
  	public Memento createMemento() {
  		return new Memento(value);
  	}
  	
  	// store the value
  	public void restoreMemento(Memento memento) {
  		this.value=memento.getValue();
  		
  	}
    
	public String getValue() {
		return value;
	}

	public void setValue(String value) {
		this.value = value;
	}
    
	public Original(String value) {
		super();
		this.value = value;
	}
  
}

Step 2: Create a memo class Memento

public class Memento {
	
     private String value;
     
     public Memento(String value) {
    	 this.value=value;
     }
	 public String getValue() {
		return value;
	 }
	 public void setValue(String value) {
		this.value = value;
	 }
     
}

Step 3: Create a class Storage for storing memos

public class Storage {
    private Memento memento;
    
	public Storage(Memento memento) {
		this.memento = memento;
	}

	public Memento getMemento() {
		return memento;
	}

	public void setMemento(Memento memento) {
		this.memento = memento;
	}
    
}

Step 4: Test

public class Test {
    public static void main(String[] args) {
		 Original original =new Original("egg");
		 Storage storage =new Storage(original.createMemento());
		 System.out.println("The initialization state is: "+original.getValue());
		 original.setValue("niu");
		 System.out.println("modified state"+original.getValue());
		 
		 original.restoreMemento(storage.getMemento());
		 System.out.println("Restored state: "+original.getValue());
		 
		 
	}
}