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Using Scanner to scan through a predefined list of strings in another class, and parse them to Ints in java

Quite a few labs have passed since my previous request for some advice and we are nearing midterms quite quickly! I am currently working on another lab right now and have ran into some slight difficulty that a little advice or guidance might help! Anyways here is whats going on!
I must have 3 classes in total:
(StationRecordMain, StationRecord, and TemperatureData)
He gave us the TemperatureData class pre-written and not able to modify it in anyway. This class holds a huge array of Strings all looking like this
"14762 20180829 89 70 80 9.6" . These are some junk number in the beginning we must throw away, the year month and day, the high temp, the low temp, avg, and difference.
This prewritten class also holds 2 methods in it, (hasNextTempRecord, getNextTempRecord).
My StationRecord class holds the following instance variables:
private int yearMonthDay = 0;
private int max = 0;
private int min = 0;
private int avg = 0;
private double dif = 0;
Finally, my MainStationRecord class holds the Scanner Object:
Scanner scan = new Scanner(tempdata.getNextTempRecord());
, an attempt to use the scanner to read through the predefined strings in the other class.
Anyways, I can supply more code that I have written but didnt want to flood this page with all of it, but those are the basics. I believe I am at a points where I know what I need to do, just need some guidance.
I need to use the Scanner to scan through all of those Strings on the other class (there are like 100 of them, so i'm assuming some sort of loop somewhere)
Then, I need to piece out each one of those strings and store their values in those private instance variables. Finally parsing them to ints and printing them out in the main class. That is where I am lost. Ive never used a scanner in such a way to do a preset of defined strings in a different class, moreover I have no experience on how to chop them up or parse them really.
Thus, if anyone could guide me in the right direction, It would be greatly appreciated! As I said before I can post the rest of my code I have written to make things easier if need be!
Until then thank you for looking!

I think if I understand it, You can easily do something like this: (I don't have complete code of yours, so this is just a suggestion)
class StationRecord {
private int yearMonthDay = 0;
private int max = 0;
private int min = 0;
private int avg = 0;
private double dif = 0;
public StationRecord(int yearMonthDay, int max, int min, int avg, double dif) {
this.yearMonthDay = yearMonthDay;
this.max = max;
this.min = min;
this.avg = avg;
this.dif = dif;
}
// rest of your code
}
public class Main
{
public static void main(String[] args) {
// rest of your codes
while (tempdata.hasNextTempRecord()) {
Scanner scan = new Scanner(tempdata.getNextTempRecord());
scan.next(); // read until a space and I don't save it for throw it away
new StationRecord(scan.nextInt(), scan.nextInt(), scan.nextInt(), scan.nextInt(), scan.nextDouble());
}
// rest of your codes
}
}
Thanks Andreas for comments too. This is what I understand and write it.

Changing an array attempt

I posted this question up earlier and it was pretty much a lazy post as I didn't provide the code I had and as a result got negged pretty badly. Thought I'd create a new one of these ....
I have an array dogArray which takes ( name, secondname, dogname )
I want to be able to change the dogname:
here's my attempt :
public void changeName(Entry [] dogArray) {
Scanner rp = new Scanner(System.in);
String namgeChange = rp.next(); {
for (int i = 0; i < dogArray.length; i++){
for (int j = 0; j < dogArray[i].length; j++){
if (dogArray[i][j] == name){
dogArray[i][j] = nameChange;
}
}
}
}
For a start it doesn't like the fact I've used ' name ' although it is defined in the dogArray. I was hoping this would read input so that users are able to change 'name' to whatever they input. This will change the value of name in the array.
Do you guys think I'm getting anywhere with my method or is it a pretty stupid way of doing it?

Only one loop is necessary, also move your call to next.
public void changeName(Entry [] dogArray) {
Scanner rp = new Scanner(System.in);
for (int i = 0; i < dogArray.length; i++){
String nameChange = rp.next(); {
if(!dogArray[i].name.equals(nameChange)){
dogArray[i].name = nameChange;
}
}
}
You might want to make this function static as well and use accessors and mutators to change and get the name. Might want to tell the user what you want them to type as well. Also there is no point in testing if the name changed, if it changed then set it, if it didnt change then set it (it doesnt hurt). Just get rid of if and keep the code inside.

How to output binary search answer?

I get the error message cannot find symbol, symbol: method books(int[], int) when I try to compile the following code.
For further explanation about what I want the code to do, see below the code.
public class books {
public void main(String[] args) {
int searchValue = 0, index;
int refNum[] = new int[4]; // the array
refNum[0] = 4; //numbers to refer to (aka to find)
refNum[1] = 6;
refNum[2] = 10;
refNum[3] = 12;
refNum[4] = 14;
int input = Integer.parseInt(enterValue.getText()); //takes user's input
for (int x = 0; x < refNum.length; x++) {
refNum[x] = input; //Tells refNum value to be
}
searchValue = input;
index = books(refNum, searchValue); //"books" is underlined
if (index != -1) {
binarySearchField.setText("We found: " + index);
} else {
binarySearchField.setText("Sorry! Not Found!");
}
public static Boolean binarySearch(String [] refNum, int left, int right, String search){
//Boolean code for later
}
This program uses binary search to find values stored in array after user inputs number, if they match then the item is successfully found. User inputs desired number in 'enterNumber' which is a TextField. Now in my code )which I'm 78% sure will work if it wasn't for this one little thing) there is an all important that is underlined which shouldn't be, (I've commented beside the line to show)
Now I had thought I was suppose to put the class name there, but apparently since it is underlined that is not the case. Any ideas on what I should be putting there in it's place?
And I apologize for the question may be a bit misleading on what I'm really asking, I just wasn't sure how to word the question.

The line
index = books(refNum, searchValue);
seems to be underlined because you have no method called books that takes an int[] and an int as arguments in your books class definition.
Now I had thought I was suppose to put the class name there Why do you assume you have to put the class name there? Figure out what you are trying to do with this code and then you will understand what goes in that line (at least in pseudocode).
Also it seems like you have a method declared directly inside another method. That is not legal in java. If this is not the case, please show us correct code.

books is your class's name..that might be the reason you are getting this error. You can't call constructor like a method. Change class's name to Books or something else..or change method's name

beginner java, help me fix my program?

I am trying to make a calculator for college gpa's. I cut out all like 20 if statements that just say what each letter grade is. I fixed my first program for anybody looking at this again. The program now works, but regardless of the letters i type in the gpa it returns is a 2.0 . If anybody sees anything wrong it would be very much appreciated...again. Thanks
import java.util.Scanner;
public class universityGPA {
public static void main(String args[]){
int classes = 4;
int units[] = {3, 2, 4, 4};
double[] grade = new double[4];
double[] value= new double[4];
int counter = 0;
double total = 0;
double gpa;
String letter;
while(classes > counter){
Scanner gradeObject = new Scanner(System.in);
letter = gradeObject.next();
if(letter.equalsIgnoreCase("A+") || letter.equalsIgnoreCase("A")){
grade[counter] = 4;
}
if(letter.equalsIgnoreCase("F")){
grade[counter] = 0;
}
value[counter] = grade[counter] * units[counter];
counter++;
}
for(int i = 0; i < classes; i++ ){
total += value[i];
}
gpa = total/classes;
System.out.println("You gpa is " +gpa);
}
}

You forgot to initialize grade. The NullPointerException is telling you that grade is null. The exception is thrown the first time you try to use grade, in the statment grade[counter] = 4;. Allocate as much space as you need with new.

Initialization of grade can be done statically as well dynamically:
double []grade = new double[4];
or
double []grade = new double[classes];
Do the same for value as well.

Here are a few pointers for cleaning up your code:
Try to be more consistent with your formatting. Make sure everything is properly indented and that you don't have lingering spaces at the beginnings or endings of lines (line 18).
You should declare variables as close to the first spot you use them as possible. This, along with making your code much more readable, minimizes the scope. For instance, on line 18, you initialize letter, but it is never used outside the scope of the while statement. You should declare the variable right there, along with the initializer (String letter = gradeObject.next()).
Declaring arrays in the type name[] form is discouraged. It is recommended to use the type[] name form instead.
Try to separate your program into distinguished sections. For instance, for this program, you can clearly see a few steps are involved. Namely, you first must grab some input, then parse it, then calculate the return value. These sections can be factored out into separate methods to clean up the code and promote reuse. While it may not seem to yield many benefits for such a simple program, once you start working on larger problems this organization will be absolutely mandatory.

NullPointerException means you are trying to access something that does not exist.
Since your grade[] is null, accessing it on line 21 by grade[counter] actually means you are accessing something that has yet to be created.
You need to initialize the array, so it actually has an instance.

Very simple code for number search gives me infinite loop

I am a newbie Computer Science high school student and I have trouble with a small snippet of code. Basically, my code should perform a basic CLI search in an array of integers. However, what happens is I get what appears to be an infinite loop (BlueJ, the compiler I'm using, gets stuck and I have to reset the machine). I have set break points but I still don't quite get the problem...(I don't even understand most of the things that it tells me)
Here's the offending code (assume that "ArrayUtil" works, because it does):
import java.util.Scanner;
public class intSearch
{
public static void main(String[] args)
{
search();
}
public static void search()
{
int[] randomArray = ArrayUtil.randomIntArray(20, 100);
Scanner searchInput = new Scanner(System.in);
int searchInt = searchInput.nextInt();
if (findNumber(randomArray, searchInt) == -1)
{
System.out.println("Error");
}else System.out.println("Searched Number: " + findNumber(randomArray, searchInt));
}
private static int findNumber(int[] searchedArray, int searchTerm)
{
for (int i = 0; searchedArray[i] == searchTerm && i < searchedArray.length; i++)
{
return i;
}
return -1;
}
}
This has been bugging me for some time now...please help me identify the problem!

I don't know about the infinite loop but the following code is not going to work as you intended. The i++ can never be reached so i will always have the value 0.
for (int i = 0; searchedArray[i] == searchTerm && i < searchedArray.length; i++)
{
return i;
}
return -1;
You probably mean this:
for (int i = 0; i < searchedArray.length; i++)
{
if (searchedArray[i] == searchTerm)
{
return i;
}
}
return -1;

I don't know what is the class ArrayUtil (I can not import is using my Netbeans). When I try to change that line with the line int[] randomArray = {1 , 2, 3, 5, 7, 10, 1 , 5}; It works perfectly.
And you should change the loop condition. I will not tell you why but try with my array and you will see the bug soon. After you see it, you can fix it:)

There are 4 basic issues here.
1. Putting searchedArray[i] == searchTerm before i < searchedArray.length can result in an out-of-bounds exception. You must always prevent that kind of code.
2. Your intention seems to be the opposite of your code. Your method name implies finding a search term. But, your code implies that you want to continue your loop scan until the search term is not found, although your loop won't do that either. Think of "for (; this ;) { that } " as "while this do that".
3. Place a break point at the beginning of "search". Then, with a small array, step through the code line by line with the debugger and watch the variables. They don't lie. They will tell you exactly what's happening.
4. Please use a standard IDE and compiler, such as Eclipse and Sun's JDK 6 or 7. Eclipse with JDK 7 is a serious combination that doesn't exhibit a strange "infinite loop" as you describe above.