重构－保护

重构－保护

重构前的代码，使用字符串处理状态

package  org.zsk.refact;

public   class  SystemPermission  {
    private String state;
    private boolean granted;
    
    public final static String REQUESTED = "REQUESTED"; 
    public final static String CLAIMED = "CLAIMED";
    public final static String DENIED = "DENIED";
    public final static String GRANTED = "GRANTED";

    public SystemPermission() {
        // TODO Auto-generated constructor stub
        state = REQUESTED;
        granted = false;
    }
    
    public void claimed(){
        if (state.equals(REQUESTED)){
            state = CLAIMED;
        }
    }
    
    public void denied(){
        if (state.equals(CLAIMED))
        state = DENIED;
    }
    
    public void granted(){
        if (state.equals(CLAIMED)){
            state = GRANTED;
            granted = true;
        }
    }
    
    public boolean isGranted(){
        return granted;
    }
    
    public String getState(){
        return state;
    }

    /** *//**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        SystemPermission permission = new SystemPermission();
        System.out.println(permission.getState());
        
        
    }

}

重构后的代码，使用类来保护状态不会被吴改。

package  org.zsk.refact;

public   class  SystemPermissionRf1  {
        private boolean granted;
        private PermissionState permission;
        
//        public final static String REQUESTED = "REQUESTED"; 
//        public final static String CLAIMED = "CLAIMED";
//        public final static String DENIED = "DENIED";
//        public final static String GRANTED = "GRANTED";

        public SystemPermissionRf1() {
            setState(PermissionState.REQUESTED);
            granted = false;
        }
        
        public void claimed(){
            if (getState().equals(permission.REQUESTED)){
                setState(permission.CLAIMED);
            }
        }
        
        public void denied(){
            if (getState().equals(permission.CLAIMED)){
                setState(permission.DENIED);
            }
        }
        
        public void granted(){
            if (getState().equals(permission.CLAIMED)){
                setState(permission.GRANTED);
                granted = true;
            }
        }
        
        public boolean isGranted(){
            return granted;
        }
        
        private void setState(PermissionState permission){
            this.permission = permission;
        }
        
        public String getState(){
            return permission.toString();
        }

        
        /** *//**
         * @param args
         */
        public static void main(String[] args) {
            // TODO Auto-generated method stub
            SystemPermissionRf1 permission1 = new SystemPermissionRf1();
            System.out.println(permission1.getState());
            
            
        }
        
        
}

package  org.zsk.refact;


public   final   class  PermissionState {
    private final String name;
    
    PermissionState(String name){
        this.name = name;
    }
    
    public String toString(){
        return name;
    }
    
    public final static PermissionState REQUESTED = new PermissionState("REQUESTED");
    public final static PermissionState CLAIMED = new PermissionState("CLAIMED");
    public final static PermissionState DENIED = new PermissionState("DENIED");
    public final static PermissionState GRANTED = new PermissionState("GRANTED");
}