Need help Solving static methods

**JosAH** · Apr 13 '07, 02:39 PM

Originally posted by nomad

Hi everyone:
I need help Please I'm still learning Java...
Here is part of my code where I'm having problems.
Problem is at public static void main(String[] args) {
The method main cannot be declared static; static methods can only be declared in a static or top level type. Given the indentation level there should
be some other code before your main method definition.

Code:

Code:
	
		public static void main(String[] args) {
			Employee emp = new Employee();
			Scanner kbd = new Scanner(System.in);
			int choice;
			System.out.println("Make a Section: ");
			System.out.println("1. Enter ");
			System.out.println("2. Find ");
			System.out.println("3. Exit ");
			System.out.print("\nPlease press Enter afer each response");
			System.out.println("Enter your chose please: ");
			choice = kbd.nextInt();
			kbd.nextLine();
			if (choice == 1) { // if 1 is select go to makePerson
				emp.inputEmployee();

			} // close the if loop

			if (choice == 2) { // if 2 is select go to find
				emp.displayMatch();

			}// close the choice==2
			if (choice == 3) {
				System.out.printf("Good bye");
			}// close the choice == 3

		}// close public static void

thanks
nomad

Check your curly braces in your source code *before* the definition of your main
method. I'm sure you forgot one of them and it upsets the compiler thinking
that you are trying to define your main method somewhere else (reread that
compiler diagnostic message again).

kind regards,

Jos

**nomad** · Apr 13 '07, 03:29 PM

Thanks Jos, I found the mistake.
Now I have a Exception in thread "main" java.lang.NullP ointerException
at company.Employe e.<init>(Employ ee.java:141)
at company.Employe e.main(Employee .java:250)

I think it has to due to my arraylist.

line 141 is

Code:

int empid = employees.size();

line 250 is

Code:

Employee emp = new Employee();

this is class for my arraylist

Code:

public class Employee {
		
		public ArrayList<Employee_listing> employees;// ArrayList of

		// contact

		int empid = employees.size();

		public void createEmployeeDB() {
			employees = new ArrayList<Employee_listing>();
		}

can you please help me.
thanks
nomad

**nomad** · Apr 13 '07, 03:43 PM

Never mind I solved that problem I did not need that statement.
But now when I run the program I get a
Exception in thread "main" java.lang.NullP ointerException
at company.Employe e.displayMatch( Employee.java:2 17)
at company.Employe e.main(Employee .java:266)

thanks
nomad

**JosAH** · Apr 13 '07, 03:56 PM

Originally posted by nomad

Never mind I solved that problem I did not need that statement.
But now when I run the program I get a
Exception in thread "main" java.lang.NullP ointerException
at company.Employe e.displayMatch( Employee.java:2 17)
at company.Employe e.main(Employee .java:266)

thanks
nomad

Here's a bit of a tip: when you see that blob of an exception stack trace
find the line nearest to the top that looks familiar (i.e. it resembles your own
code). Check the line number and just above that line print out everything
you think can be of interest. A NullPointerExce ption usually means that you
forgot to instantiate an object (using 'new ...'). Run your program again and
add more System.out.prin tln( ... ) statements to find the bug.

kind regards,

Jos

**nomad** · Apr 13 '07, 04:05 PM

OK I did that.
I know it has has to be the next statement which is a find statement.
Made a System.out.prin tln("HERE IS THE MISTAKE:");
after that I get the NullPointerExce ption.
can you please give be a clue or help me

Here is my code

Code:

			Scanner input_flag = new Scanner(System.in);
			System.out.println("Enter Employee Id Number AB1234==>");
			String empid = input_flag.next();
			String id_flag = "";
			System.out.println("HERE IS THE MISTAKE:"); 
			boolean notfound = true;
			for (Employee_listing e : employees) {
				String emp = e.getEmpId();
				if (emp.equals(id_flag)) {
					System.out.println("Hello" + ("e.lname"));
					notfound = false;
				}
			}
			if (notfound == true) {

			System.out.print("Enter Last Name Doe==>");
			String ln = input_flag.next();

Thanks Jos

nomad

**JosAH** · Apr 13 '07, 04:29 PM

Originally posted by nomad

OK I did that.
I know it has has to be the next statement which is a find statement.
Made a System.out.prin tln("HERE IS THE MISTAKE:");
after that I get the NullPointerExce ption.
can you please give be a clue or help me

Here is my code

Code:

			Scanner input_flag = new Scanner(System.in);
			System.out.println("Enter Employee Id Number AB1234==>");
			String empid = input_flag.next();
			String id_flag = "";
			System.out.println("HERE IS THE MISTAKE:"); 
			boolean notfound = true;
			for (Employee_listing e : employees) {
				String emp = e.getEmpId();
				if (emp.equals(id_flag)) {
					System.out.println("Hello" + ("e.lname"));
					notfound = false;
				}
			}
			if (notfound == true) {

			System.out.print("Enter Last Name Doe==>");
			String ln = input_flag.next();

Thanks Jos

nomad

My guess is that your 'employees' variable is null. Print that one out before you
start the loop, so you're sure about that. Don't just print out a bit of text but
print out all the variable values you suspect to be incorrect.

kind regards,

Jos

**nomad** · Apr 13 '07, 05:47 PM

OK did to things.
1. I made a system print on empid and ln fields. It gave the the throw after empid.
2. I ask the a system count and after empid. it again came back with a throw.
3. I made a (what I call it) a tester program and I drop some data into it .
I just added the empid only. Same results...in fact it did not even see the data that I add. I did a test asking for a count...

What do I do next. Remember I'm just a beginner.

thanks
nomad
Also is this better find statement. that is once if figure this problem

empid has a Can only iterate over an array or an instance of java.lang.Itera ble

Code:

	
Scanner input_flag = new Scanner(System.in);
System.out.println("Enter Employee Id Number AB1234==>");
			int idx =0;
			String empid = input_flag.next();
			boolean notfound=true;

			for(String id : empid){
				if(id.equals(input_flag)){
					System.out.println("Employee is in the db please go back to Menu");
					notfound = false;
				}
					idx++;
				}
				if(notfound==true){
does the rest of my code...
}

**r035198x** · Apr 14 '07, 06:59 AM

Originally posted by nomad

OK did to things.
1. I made a system print on empid and ln fields. It gave the the throw after empid.
2. I ask the a system count and after empid. it again came back with a throw.
3. I made a (what I call it) a tester program and I drop some data into it .
I just added the empid only. Same results...in fact it did not even see the data that I add. I did a test asking for a count...

What do I do next. Remember I'm just a beginner.

thanks
nomad
Also is this better find statement. that is once if figure this problem

empid has a Can only iterate over an array or an instance of java.lang.Itera ble

Code:

	
Scanner input_flag = new Scanner(System.in);
System.out.println("Enter Employee Id Number AB1234==>");
			int idx =0;
			String empid = input_flag.next();
			boolean notfound=true;
 
			for(String id : empid){
				if(id.equals(input_flag)){
					System.out.println("Employee is in the db please go back to Menu");
					notfound = false;
				}
					idx++;
				}
				if(notfound==true){
does the rest of my code...
}

What, if I may ask, is this line supposed to be doing?

Code:

 for(String id : empid){

**nomad** · Apr 16 '07, 02:20 PM

Originally posted by r035198x

What, if I may ask, is this line supposed to be doing?

Code:

 for(String id : empid){

The program starts looping throught the array empid using a for() loop. It first compares the variable being set (id) with the employee id (empid) being searched for (input_flag), If they are eqaul then the name is printed, if not found then it continues with the enter info.

nomad

**r035198x** · Apr 16 '07, 02:34 PM

Originally posted by nomad

The program starts looping throught the array empid using a for() loop. It first compares the variable being set (id) with the employee id (empid) being searched for (input_flag), If they are eqaul then the name is printed, if not found then it continues with the enter info.

nomad

But you have

Code:

 String empid = input_flag.next();

and so empid may not be the array you think it is.

**nomad** · Apr 16 '07, 03:11 PM

can you help me solve this.
How do I get the scanner (input_flag) to find empid in a arraylist?

nomad

**r035198x** · Apr 16 '07, 03:15 PM

Originally posted by nomad

can you help me solve this.
How do I get the scanner (input_flag) to find empid in a arraylist?

nomad

What object types do you have in the ArrayList? Are they Strings or are they Employees?

**nomad** · Apr 16 '07, 03:32 PM

They are strings for empid, lname, fname

nomad

**r035198x** · Apr 16 '07, 03:55 PM

Originally posted by nomad

They are strings for empid, lname, fname

nomad

Then your design is looking very bad. You should use an Employee class to group the data and store the values as Employees.

With your current design, you may end up comparing an empid with a lname which is probably not what you want to do. You may have to make sure the id is at the 1st, 4th, 7th position e.t.c for the comparison to work properly

Need help Solving static methods

Need help Solving static methods

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