Why won't this PrintWriter populate this file?
I have a program that takes Giraffe
from a text file, creates from them ArrayList
and LinkedList
(redundantly, I know ... LinkedList
was a requirement of the second part of the assignment and I liked mine ArrayList
), sorts who their parents are, and then has to print the VBA macro to the file.
File ( D:\\Java\\Macro.txt
) is created, but it is empty. Why is nothing printed in the file? I think there is a problem with creating an array to return to the main function.
I suspect the problem is in the method GetYearGroup
in the class Herd
and how it interacts with PrintWriter
, which is on lines 51-83 of the class Main
.
Here is the code:
HW4_Name.java (main)
package giraffe;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;
public class HW4_Name {
public static void main(String[] args) throws IOException {
ArrayList<Giraffe> giraffes = new ArrayList<>();
String temp[] = new String[13];
String header = "";
String fileLocation = "theHerd.txt";
File textFile = new File(fileLocation);
Scanner in = new Scanner(textFile);
if (textFile.canRead()) {
header = in.nextLine();
while (in.hasNextLine()) {
temp = in.nextLine().split("\\t", 13);
giraffes.add(new Giraffe(temp));
}
}
Herd herd = new Herd();
for(int i = 0; i < giraffes.size(); i++){
Giraffe g = giraffes.get(i);
herd.Add(g);
}
int nGiraffes = herd.Size();
for(int i = 0; i < nGiraffes; i++){
Giraffe g = herd.GetAt(i);
int nSire = g.getSireId();
if (nSire != -1){
g.setSire(herd.Find(nSire));
}
int nDam = g.getDamId();
if (nDam != -1){
g.setDam(herd.Find(nDam));
}
}
in.close();
PrintWriter pw = new PrintWriter("C:\\Java\\Macro.txt");
int nHeight = 500;
int nWidth = 900;
int nYearHeight = nHeight / 13;
int nRectangle = 0;
for(int i = 0; i < 13; i++){
int nLowYear = 50 + 5 * i;
Giraffe[] ThisGroup = herd.GetYearGroup(nLowYear, nLowYear + 5);
int nThisGroup = ThisGroup.length;
int nXSpacing = nWidth / (nThisGroup + 1);
int nYPos = 10 + nYearHeight * i;
for(int j = 0; j < nThisGroup; j++){
nRectangle++;
int nXPos = 10 + nXSpacing/2 + nXSpacing * j;
Giraffe g = ThisGroup[j];
g.setRectangle(nRectangle);
String strName = g.getName();
pw.println("Call Box(" + nXPos + ", " + nYPos + ", \"" +strName + "\")");
}
}
for(int i = 0; i < nGiraffes; i++){
Giraffe g = herd.GetAt(i);
Giraffe gSire = g.getSire();
if (gSire != null){
int nParentRectangle = gSire.getRectangle();
nRectangle = g.getRectangle();
if (nParentRectangle > 0 && nRectangle > 0){
pw.println("Call DadLine(" + nParentRectangle + ", " + nRectangle + ")");
}
}
Giraffe gDam = g.getDam();
if(gDam != null){
int nParentRectangle = gDam.getRectangle();
if (nParentRectangle > 0 && nRectangle > 0){
pw.println("Call MomLine(" + nParentRectangle + ", " + nRectangle + ")");
}
}
}
pw.close();
}
}
Giraffe.java
package giraffe;
import java.util.ArrayList;
public class Giraffe extends Object {
private String birthLocation, subSpecies, zoo, city, state, event, name,
localId, sex, eachGiraffe;
private int gId, birthYear, sireId, damId, gRectangle;
private Giraffe gSire, gDam;
public Giraffe(String array[]){
this.sex = String.format("%-1s",array[1]);
this.birthLocation = String.format("%-12s",array[5]);
this.localId = String.format("%-7s",array[6]);
this.name = String.format("%-20s",array[7]);
this.subSpecies = String.format("%-14s",array[8]);
this.zoo = String.format("%-35s",array[9]);
this.city = String.format("%-17s",array[10]);
this.state = String.format("%-13s",array[11]);
this.event = String.format("%-7s",array[12]);
this.gId = Integer.parseInt(array[0]);
this.birthYear = Integer.parseInt(array[2].substring(0,4));
if(array[3].equals("WILD") || array[3].equals("UNK")){
this.sireId = -1;
}
else{
this.sireId = Integer.parseInt(array[3]);
}
if(array[4].equals("WILD") || array[4].equals("UNK")){
this.damId = -1;
}
else{
this.damId = Integer.parseInt(array[4]);
}
}
public String getName(){
return this.name;
}
public int getId(){
return gId;
}
public int getBirthYear(){
return birthYear;
}
public int getSireId(){
return sireId;
}
public int getDamId(){
return damId;
}
public Giraffe getSire(){
return gSire;
}
public int getRectangle(){
return gRectangle;
}
public Giraffe getDam(){
return gDam;
}
public void setSire(Giraffe nSire){
this.gSire = nSire;
}
public void setDam(Giraffe nDam){
this.gDam = nDam;
}
public void setRectangle(int nRectangle){
this.gRectangle = nRectangle;
}
public String toString(){
eachGiraffe = ("" + this.gId);
return eachGiraffe;
}
}
Herd.java
package giraffe;
public class Herd extends LinkedList{
public Herd(){
}
public void Add(Giraffe g){
InsertRight(g);
}
public Giraffe Find(int idNumber){
Giraffe g = null;
Node currNode = start;
while(currNode != null && currNode.o.getId() != idNumber){
currNode = currNode.next;
}
if(currNode.o.getId() == idNumber){
g = currNode.o;
}
return g;
}
public Giraffe GetAt(int nIndex){
Giraffe g = null;
Node currNode = start;
for(int i = 0; i < nIndex; i++){
if(currNode != null){
currNode = currNode.next;
}
}
g = currNode.o;
return g;
}
public Giraffe[] GetYearGroup(int nBegin, int nEnd){
int nGiraffes = Size();
int nInGroup = 0;
for(int i = 0; i < nGiraffes; i++){
Giraffe g = GetAt(i);
int nBirthYear = g.getBirthYear();
if (nBegin <= nBirthYear && nBirthYear < nEnd){
nInGroup++;
}
}
Giraffe[] gary = new Giraffe[nInGroup];
nInGroup = 0;
for(int i = 0; i < nGiraffes; i ++){
Giraffe g = GetAt(i);
int nBirthYear = g.getBirthYear();
if(nBegin <= nBirthYear && nBirthYear < nEnd){
gary[nInGroup] = g;
nInGroup++;
}
}
return gary;
}
}
LinkedList.java
package giraffe;
public class LinkedList {
protected Node start;
private int errorReturn;
public LinkedList(){
start = null;
}
public LinkedList(int errorValue){
start = null;
errorReturn = errorValue;
System.out.println(errorReturn);
}
public boolean isEmpty(){
return (start == null);
}
public void InsertRight(Giraffe data){
Node currNode;
if (start == null){
start = new Node(data,start);
}
else{
currNode = start;
while (currNode.next != null){
currNode = currNode.next;
}
currNode.next = new Node (data, null);
}
}
public int Size(){
int length = 0;
Node currNode = start;
while(currNode != null){
length++;
currNode = currNode.next;
}
return length;
}
public void Display(){
Node currNode = start;
System.out.println("List contents: ");
while (currNode != null){
currNode = currNode.next;
}
System.out.println("--------------------------");
}
}
Node.java
package giraffe;
public class Node {
Giraffe o;
Node next;
public Node(Giraffe giraffe, Node nextNode){
o = giraffe;
next = nextNode;
}
}
Decision
Thanks to durron597 for pointing out that BirthYear was not comparable to GetYearGroup.
Replacement:
for(int i = 0; i < 13; i++){
int nLowYear = 50 + 5 * i;
Through:
for(int i = 0; i < 13; i++){
int nLowYear = 1950 + 5 * i;
The problem has been fixed.
source to share
I see two problems, each of which can lead to what you see:
- You are listing into a directory
C:\\Java\\Macro.txt
, but you are using a relative path to searchtheHerd.txt
. Try changing your filetheHerd.txt
to an absolute path, or useClass.getResourceAsStream()
if the file is in your classpath.- Use the debugger to see what objects
Giraffe
are being created at all
- Use the debugger to see what objects
-
Checking your birth year seems odd:
for(int i = 0; i < 13; i++){ int nLowYear = 50 + 5 * i; Giraffe[] ThisGroup = herd.GetYearGroup(nLowYear, nLowYear + 5);
-
This only checks for years in the range 50, 55, up to 115. However, in your class,
Giraffe
you do this:this.birthYear = Integer.parseInt(array[2].substring(0,4));
This will work (i.e. not throw an exception
ArrayIndexOutOfBounds
) for four digit dates, none of which are in the 50-115 range. However, if you set your year to a value like0073
(you must put leading zeros), then your program will print results likeCall Box(235, 162, "GiraffeName ")
. You probably want to change this value50
to1950
.
-
There are other code smells in your program; I suggest reading things like (in ascending order of time):
- Java encapsulation concept is not clear
- Java naming conventions
- Single principle of responsibility
- Clean Code, Robert Martin
But those two bits of code should get started.
source to share