Data update

Task/Memory-layout-of-a-data-structure/Java/memory-layout-of-a-data-structure.java

@@ -0,0 +1,74 @@
+public final class MemoryLayoutOfDataStructure {
+
+	public static void main(String[] aArgs) {
+		RS232Pins9 plug = new RS232Pins9();
+		System.out.println(plug.getPin("receivedData"));
+		plug.setPin(2, Status.ON);
+		System.out.println(plug.getPin("receivedData"));
+		plug.setPin("signalGround", Status.ON);
+		plug.displayPinStatus();
+	}
+	
+}
+
+enum Status { OFF, ON }
+	
+final class RS232Pins9 {
+	
+	public Status getPin(int aPinNumber) {
+		for ( Pin pin : Pin.values() ) {
+			if ( pin.pinNumber == aPinNumber ) {
+				return pin.status;
+			}
+		}
+		throw new IllegalArgumentException("Unknown pin number: " + aPinNumber);
+	}
+	
+	public Status getPin(String aName) {
+		for ( Pin pin : Pin.values() ) {
+			if ( pin.name() == aName ) {
+				return pin.status;
+			}
+		}
+		throw new IllegalArgumentException("Unknown pin name: " + aName);
+	}
+	
+	public void setPin(int aPinNumber, Status aStatus) {
+		for ( Pin pin : Pin.values() ) {
+			if ( pin.pinNumber == aPinNumber ) {
+				pin.status = aStatus;
+			}
+		}
+	}
+	
+	public void setPin(String aName, Status aStatus) {
+		for ( Pin pin : Pin.values() ) {
+			if ( pin.name() == aName ) {
+				pin.status = aStatus;
+			}
+		}
+	}
+	
+	public void displayPinStatus() {
+		for ( Pin pin : Pin.values() ) {
+			System.out.println(String.format("%-29s%s", pin.name() + " has status ", pin.status));
+		}			
+	}
+	
+	private enum Pin {
+		
+		carrierDetect(1, Status.OFF), receivedData(2, Status.OFF), transmittedData(3, Status.OFF),
+		dataTerminalReady(4, Status.OFF), signalGround(5, Status.OFF), dataSetReady(6, Status.OFF),
+		requestToSend(7, Status.OFF), clearToSend(8, Status.OFF), ringIndicator(9, Status.OFF);
+		
+		private Pin(int aPinNumber, Status aStatus) {
+			pinNumber = aPinNumber;
+			status = aStatus;
+		}
+		
+		private int pinNumber;
+		private Status status;		
+		
+	}
+
+}