Question

Please use JAVA only

Write a Printer device, which also derives from generic devices, but this time includes the notion of jobs to be printed. Like Disk, a Printer should extend from Device. Additionally, a Printer should have an intwhich represents the number of jobs currently in the printer's print queue. We can add or complete print jobs, or check the number currently in the queue, but for this assignment that is the extent of what we expect (we will not be passing full-fledged print jobs to the class, we will just keep track of the number of jobs).

The class should implement the following public methods:

• public Printer(String name, int id) Initializes the device with name and ID as before. Make sure to use the parent's constructor, otherwise the parent's fields will not be set. Additionally, the number of print jobs should initially be set to zero.
• @Override public String getCategory() This should return the value "printer".
• @Override public void disable() Whenever a printer device is disabled, the number of active print jobs should be reset to zero, in addition to anything that the disable() method was already doing in the parent class.
• public void submitJob() Increase the number of print jobs by one, but only if the printer device is currently enabled.
• public int numJobs() Report the number of currently active print jobs.
• public void completeJob() Complete one of the currently active print jobs (i.e. reduce the number of jobs by one if there are more than zero jobs to print).

Example:

Below is a sample run demonstrating how the class would function using the following input:
1 abc 2.0 3 def 4.0 6 7 xyz 5.5

> Device dev = new Device("controller", 0);
> System.out.println(dev);
generic 0, controller
> dev.isEnabled()
false
> dev.enable();
> dev.isEnabled()
true
> Disk disk = new Disk("HDD", 1, 123456789);
> System.out.println(disk);
disk 1, HDD (123456789 bytes)
> disk.getSize()
123456789
> disk.enable();
> disk.isEnabled()
true
> Disk disk2 = new Disk("SDD", 2, 256000000000L);
> Printer p = new Printer("Laser Printer", 3);
> p.numJobs()
0
> p.submitJob();
> p.numJobs()
0
> p.isEnabled()
false
> p.enable();
> p.submitJob();
> p.numJobs()
1
> p.submitJob();
> p.numJobs()
2
> p.completeJob();
> p.numJobs()
1
> p.completeJob();
> p.completeJob();
> p.numJobs()
0
> Device[] devices = {dev, disk, disk2, p};
> for (Device d : devices) { System.out.println(d); }
generic 0, controller
disk 1, HDD (123456789 bytes)
disk 2, SDD (256000000000 bytes)
printer 3, Laser Printer

• Please make sure that it passes the following: https://repl.it/@micky123/ColorfulGranularCode

Answer 1

Printer.java

// Declare class Printer inheritance from parents(Device) class
public class Printer extends Device {
    private int jobNum; // Initialize
    public Printer(String name, int id) {
        super(name, id); // super() get info from parents class
        this.jobNum=0; // declare
    }
    @Override public String getCategory() {
        return "printer"; // @Override category to "printer"
    }
    @Override public void disable() {
        super.disable(); // Disable the device
        this.jobNum=0; // and set number of jobs to 0
    }
    public void submitJob() {
        if (super.isEnabled()==true) { //Check if the device is enable
            this.jobNum++; //number of job increase by 1
        }
    }
    // return current number of job
    public int numJobs() {
        return this.jobNum;
    }
    //check if there is still job and decrease by 1 to complete 1 job
    public void completeJob() {
        if (this.jobNum >0) {
            this.jobNum--;
        }
    }
}

Device.java

// declare class Device
public class Device {
    // Initialize all variables as private
    private String name;
    private int id;
    private boolean enabledStatus;
    // build up the constructor method
    public Device(String name, int id) {
        this.name=name;
        this.id=id;
        this.enabledStatus=false;
    }
    // getName() method return the name
    public final String getName() {
        return this.name;
    }
    // getID () method return the id
    public final int getID() {
        return this.id;
    }
    // getCategory() return "generic"
    public String getCategory(){
        return "generic";
    }
    // enable() doesn't have a return but set enabledStatus to true
    public void enable() {
        this.enabledStatus = true;
    }
    // disable() doesn't have a return but set enabledStatus to false
    public void disable() {
        this.enabledStatus = false;
    }
    // return boolean to check if the device is enable/disable
    public boolean isEnabled() {
        return this.enabledStatus;
    }
    // return a string
    @Override public String toString() {
        return (getCategory() + " "+getID() +", "+getName());
    }
}

Disk.java

// Declare class Disk inheritance from class Device
class Disk extends Device {
    // Initialize variable
    private long size;
    public Disk(String name, int id, long size) {
        super(name, id); // super() for children class to access parents' infomation
        this.size = size;
    }
    @Override public String getCategory() {
        return "disk"; // @Override category to "disk"
    }
    // return the size of
    public long getSize() {
        return (this.size);
    }
    // @Override: use super() to acess parents' info and add new size info
    @Override public String toString() {
        return super.toString() + String.format(" (%d bytes)",getSize());
    }
}