I improved on the employee processing program and came up with employee and payroll classes which worked.

/**
 * Payfile, hirefile, and firefile.
 * 
 * @Quang Pham 
 * @4/8/13
 */

public class Employee implements Comparable
{
    
        Comparable cp;
        public String firstName;
        public String lastName;
        public String gender;
        public int tenure;
        public String rate;
        public double salary;
   
       //Constructor for objects of class Employee
       public Employee(String firstName, String lastName, String gender, int tenure, String rate, double salary)
       {
           //Initialize instance variables
           this.firstName = firstName;
           this.lastName = lastName;
           this.gender = gender;
           this.tenure = tenure;
           this.rate = rate;
           this.salary = salary;
        }
        
        public Employee(String firstName, String lastName, String gender)
        {
            this.firstName = firstName;
            this.lastName = lastName;
            this.gender = gender;
        }
        
        public String getLastName()
        {
            return lastName;
        }
        
        public int compareTo(Object o)
        {
            Employee e = (Employee) o;
            return lastName.compareTo(e.getLastName());
        }
    }
  
/*        Payfile
DEBBIE     STARR           F 3 W 1000.00
JOAN       JACOBUS         F 9 W  925.00
DAVID      RENN            M 3 H    4.75
ALBERT     CAHANA          M 3 H   18.75
DOUGLAS    SHEER           M 5 W  250.00
SHARI      BUCHMAN         F 9 W  325.00
SARA       JONES           F 1 H    7.50
RICKY      MOFSEN          M 6 H   12.50
JEAN       BRENNAN         F 6 H    5.40
JAMIE      MICHAELS        F 8 W  150.00

        Hirefile
BARRY      ALLEN           M 0 H    6.75
NINA       PINELLA         F 0 W  425.00
LANE       WAGGER          M 0 W  725.00
        
        Firefile
JEAN       BRENNAN         F
RICKY      MOFSEN          M
*/

/**
 * Print table of employees and manipulate employee list.
 * 
 * @Quang Pham 
 * @3/12/13
 */
import java.io.*;
import java.util.Scanner;

public class Payroll
{
    ObjectList employeeList;

    public Payroll()
    {
        employeeList = new ObjectList();
    }

    public void getEmployees() throws IOException
    //getEmployees() adds employee to payroll.
    {

        Scanner readEmployees= new Scanner(new File("payfile.txt"));
        String [] employeeInfo; 
        String line;
        String firstName;
        String lastName;
        String gender;
        int tenure; 
        String rate;
        double salary;
     

        while(readEmployees.hasNext()){
            line= readEmployees.nextLine();
            employeeInfo= line.split("[ ]+");
            firstName= employeeInfo[0];
            lastName= employeeInfo[1];
            gender= employeeInfo[2];
            tenure= Integer.parseInt(employeeInfo[3]);
            rate= employeeInfo[4];
            salary=Double.parseDouble(employeeInfo[5]);
            employeeList.addLast(new Employee(firstName,lastName,gender,tenure,rate,salary));
        }
    }

   
    /*public Payroll(LineWriter lw)
    {
        this.lw = lw;
        this.firstname = new ObjectList();
        this.lastname = new ObjectList();
        this.gender = new ObjectList();
        this.tenure = new ObjectList();
        this.payrate = new ObjectList();
        this.salary = new ObjectList();
        this.output = new ObjectList();
        this.input = new ObjectListNode();
    } 
    */

    /*public void readfile()
    {
    int n = 0;
    File file = new File("payfile.txt");
    try{
    System.out.println ("FirstName  LastName  Gender  Tenure  Rate  Salary");
    Scanner scanner = new Scanner(file);//file
    while(scanner.hasNextLine())
    {
    String line = scanner.nextLine();
    Scanner lineScanner = new Scanner(line);
    lineScanner.useDelimiter("\\s+");

    while(lineScanner.hasNext())
    {

    firstname.insert(lineScanner.next());
    lastname.insert(lineScanner.next());
    gender.insert(lineScanner.next());
    tenure.insert(lineScanner.next());
    payrate.insert(lineScanner.next());
    salary.insert(lineScanner.next());
    }
    //Print employee payroll
    /*System.out.println ("firstname: " + firstname);
    System.out.println ("lastname:  " + lastname);
    System.out.println ("gender:  " + gender);
    System.out.println ("tenure:  " + tenure);
    System.out.println ("payrate:  " + payrate);
    System.out.println ("salary:  " + salary);
    System.out.println ("  ");

    System.out.println ("line" + n + ":  " + line);
    n = n + 1;
    }

    System.out.println ("  ");
    System.out.println ("There are " + n + " employees in the company.");
    System.out.println ("  ");
    }
    catch(FileNotFoundException e)
    { e.printStackTrace();} 
    }

    /*public void insert()
    {
    // File file = new File("payfile.txt");
    /*
    try{
    Scanner scanner = new Scanner(file);

    while(scanner.hasNextLine())
    {
    String line = scanner.nextLine();
    Scanner lineScanner = new Scanner(line);
    lineScanner.useDelimiter("\\s+");
    while(lineScanner.hasNext())
    {

    //emp.firstname = linescanner.next();

    firstname.insert(lineScanner.next());
    lastname.insert(lineScanner.next());
    gender.insert(lineScanner.next());
    tenure.insert(lineScanner.next());
    payrate.insert(lineScanner.next());
    salary.insert(lineScanner.next());

    //Print employee payroll
    /*System.out.println ("firstname: " + firstname);
    System.out.println ("lastname:  " + lastname);
    System.out.println ("gender:  " + gender);
    System.out.println ("tenure:  " + tenure);
    System.out.println ("payrate:  " + payrate);
    System.out.println ("salary:  " + salary);

    System.out.println ("line:  " + line);

    }

    //ol.insertAfter();

    }        
    } catch(FileNotFoundException e)
    { e.printStackTrace();}
     */

    /*public void printer(LineWriter lw)
    {
    String msg = " FirstName " + " LastName " + " Gender " + " Tenure " +
    " PayRate " + " Salary "; 
    output.insert(msg);
    //System.out.println(msg);
    //ObjectListNode p = list;

    while (oln != null);
    {
    System.out.println(output.getFirst());
    System.out.println("  " + firstname.getFirst() + "     " + lastname.getFirst() + "\t" + gender.getFirst() +
    "\t" + tenure.getFirst() + "\t" + payrate.getFirst() + "\t" + salary.getFirst());
    //System.out.println(output.getSecond());
    //System.out.println(" " + firstname.getSecond() + "     " + lastname.getSecond() + "\t" + gender.getSecond() +
    //    "\t" + tenure.getSecond() + "\t" + payrate.getSecond() + "\t" + salary.getSecond());

    // System.out.println(output.getLast());
    System.out.println("  " + firstname.getLast() + "     " + lastname.getLast() + "\t" + gender.getLast() +
    "\t" + tenure.getLast() + "\t" + payrate.getLast() + "\t" + salary.getLast());

    // oln.getNext();
    // oln.getInfo();

    //traverse linked list and print next employee entries.
    // ol.traverse(); 
    //{
    p = list;
    while (p != null) 
    {
    System.out.println(p.getInfo());
    p = p.getNext();

    System.out.println("  " + firstname.getFirst() + "     " + lastname.getFirst() + "\t" + gender.getFirst() +
    "\t" + tenure.getFirst() + "\t" + payrate.getFirst() + "\t" + salary.getFirst());

    System.out.println(" " + firstname.getLast() + "    " + lastname.getLast() + "\t" + gender.getLast() +
    "\t" + tenure.getLast() + "\t" + payrate.getLast() + "\t" + salary.getLast());

    }  

                    
    /**
     * employeeTable()-traverse employeeList and outputs each node into a table format
     */
    public void employeeTable()
    {
        Employee node;    
        ObjectListNode p = employeeList.getFirstNode();
        //print header
        System.out.println("Name                 Gender          Tenure            Rate             Salary");
        //print each employee
        while (p != null) {
            node=(Employee)p.getInfo();
            System.out.printf("%s %s\t\t%s\t\t%d\t\t%s\t\t%.2f\n",node.firstName,node.lastName,node.gender,node.tenure,node.rate,node.salary);
            p = p.getNext();
        }
        System.out.println();//for a space in output
    }

    /**
     * numEmployees()-traverse list and returns number of employees(using count method in object list)
     */
    public void numEmployees(){
        System.out.println("Number of Employees in Company: "+ employeeList.size()+ "\n");
    }

    /**
     * women()-output first names of women on the payroll. 
     */
    public void women(){
        Employee employee;    
        ObjectListNode p = employeeList.getFirstNode();
        String gender;

        System.out.println("Women on payroll:");
        while (p != null) {
            employee=(Employee)p.getInfo();
            gender=employee.gender;
            if(gender.equals("F")){
                System.out.println(employee.firstName);
            }
            p = p.getNext();
        }
        System.out.println();
    }

    /**
     * experienced()-output weekly employees who make more than $35,000 and is with the company for at least
     * 5 years. 
     */
    public void experienced(){
        final int WEEKS_IN_YEAR=52;
        Employee employee;    
        ObjectListNode p = employeeList.getFirstNode();
        double yearlySal; //how much money that employee makes a year

        while (p != null) {
            employee=(Employee)p.getInfo(); 
            if((employee.rate).equals("W")){
                yearlySal=(employee.salary)*WEEKS_IN_YEAR;
                if(yearlySal>35000 && employee.tenure >= 5 )
                {
                    System.out.println("Weekly employees who make more than $35,000 and with the company for 5 years.");
                    System.out.println(employee.firstName+" "+employee.lastName);
                }
            }
            p = p.getNext();
        }
        System.out.println(); 
    }

    /**
     * method raise()- give raises to some employees and print out their names and new salaries
     */
    public void raise(){
        Employee employee;    
        ObjectListNode p = employeeList.getFirstNode();
        String rate;
        double oldSalary;
        //headings
        System.out.println("Employees who recieved a raise");
        System.out.println("Name\t\t\tNew Salary");

        while (p != null) {
            employee=(Employee)p.getInfo();
            rate=employee.rate;
            oldSalary=employee.salary;//salary at the start
            if(rate.equals("H")){
                if(oldSalary< 10.00){
                    employee.salary+= .75;
                }
            }
            else {//if rate is weekly
                if(oldSalary<350.00){
                    employee.salary+= 50.00;

                }
            }
            if(oldSalary<employee.salary)//if recieved a raise
                System.out.printf("%s %s\t\t%.2f\n",employee.firstName,employee.lastName,employee.salary);
            p = p.getNext();
        }
        System.out.println(); //add space in output
    }

    /**
     * method alphaOrder()- puts list in order by last name
     * 
     */
    public void alphaOrder(){
        ObjectList newList= new ObjectList();//the ordered list
        Object object;
        ObjectListNode p= new ObjectListNode();
        Employee employee;
        while (employeeList.getFirstNode()!= null) 
        {
            object=employeeList.removeFirst();
            newList.insert(object);
        }
        employeeList=newList;
        p=employeeList.getFirstNode();
        System.out.println("Employees in alphabetical order by last name and their salaries.");
        //print the employees
        while(p!= null)
        {
            
            employee=(Employee)p.getInfo();
            System.out.printf("%s %s\t%.2f\n",employee.firstName,employee.lastName,employee.salary);
            p = p.getNext();
        }
        System.out.println();      
    }

    /**
     * method hireEmployees- reads hirefile and inserts them into the linked list
     */
    public void hireEmployees() throws IOException{
        Scanner newEmployees= new Scanner(new File("hirefile.txt"));//read new employees
        ObjectListNode p;
        Employee employee;
        String [] employeeInfo;
        String line;
        String firstName;
        String lastName;
        String gender;
        int tenure; 
        String rate;
        double salary;

        while(newEmployees.hasNext()){
            line=newEmployees.nextLine();
            employeeInfo= line.split("[ ]+");
            firstName= employeeInfo[0];
            lastName= employeeInfo[1];
            gender= employeeInfo[2];
            tenure= Integer.parseInt(employeeInfo[3]);
            rate= employeeInfo[4];
            salary=Double.parseDouble(employeeInfo[5]);
            employeeList.insert((Object)new Employee(firstName,lastName,gender,tenure,rate,salary));
        }

        p= employeeList.getFirstNode();
        System.out.println("List afer certain employees were hired.");
        while(p!= null){
            employee=(Employee) p.getInfo();
            System.out.println(employee.firstName+" "+employee.lastName);
            p = p.getNext();
        }
        System.out.println();
    }

    /**
     * method fireEmployees()- reads firefile and fires employees by removing from linked list
     */
    public void fireEmployees() throws IOException{
        Scanner toFire= new Scanner(new File("firefile.txt"));//read new employees
        String [] employeeInfo;
        ObjectListNode p;
        Employee employee;
        String line;
        String firstName;
        String lastName;
        String gender;
        int tenure; 
        String rate;
        double salary;
        System.out.println("List after certain employees were fired.");
        while(toFire.hasNext()){
            line=toFire.nextLine();
            employeeInfo= line.split("[ ]+");
            firstName= employeeInfo[0];
            lastName= employeeInfo[1];
            gender= employeeInfo[2];
            employeeList.remove((Object)new Employee(firstName,lastName,gender));
        }

        p=employeeList.getFirstNode();
        while(p!=null){
            employee=(Employee)p.getInfo();
            System.out.println(employee.firstName+" "+employee.lastName);
            p = p.getNext();
        }
        System.out.println();

    }
}

//public void femalesInCompany();
//while ol.gender == 'F';

//System.out.println(firstname);
//p = p.getNext();

//sort list(); //sort nodes according to last name();
//print salaries of employees
/*insert (hirefile.txt)(); //insert hirefile into linked list
{

}
// while (oln != null)
return newfile1;
 */

/*delete (firefile.txt)(); //delete firefile from linked list
{

}
// while (oln != null)
return newfile2;
 */

// a.)  Read data from payfile.txt into ObjectList and ObjectListNode.

// b.)  Traverse the list and output info field of each ObjectListNode into table format.

// c.)  Traverse the list and output the number of employees in company.

// d.)  Traverse the list and output the first name of all women employees.

// e.)  The first name, last name, and salary of weekly employees who make more than $35,000 per year and who have been 
// with the company for at least five years.

// f.)  Give a raise of $.75 per hour to employees who are paid on an hourly basis and make less than $10.00 per hour.

// g.)  Give a raise of $50.00 per week to employees who are paid on a weekly basis and make less than $350.00 per week.

// h.)  Output first name, last name, and new salaries for employees who got a raise.

// i.)  Sort the nodes of linked list into alphabetical order according to last name and print first and last names and

// j.)  Print the salaries for each employee on the payroll.

// k.)  Insert the hirefile.txt employees into payroll and print first and last names of each employee.

// l.)  Delete the firefile.txt emplyees from payroll and print first and last names of each employee.

burakaltr, on 05 March 2013 - 02:03 PM, said:

I couldn't open the code before.

burakaltr, on 05 March 2013 - 02:03 PM, said:

I couldn't open the code before.

This is my improved InfixToPostfix Program.

/**
 * Driver to start execution of program.
 * 
 * @Quang Pham 
 * @2/21/13
 */
import java.io.*;

import java.util.Scanner;

public class Driver
{
    LineWriter lw;
    public Driver (LineWriter lw)
    {
        lw = new LineWriter("csis.txt");   
    }
    String infix = "";
    Scanner keyboard = new Scanner(System.in);

    public static void main(String[] args)throws IOException
    {
        LineWriter lw = new LineWriter("csis.txt");
        InfixToPostfix inf = new InfixToPostfix();
        //ObjectStack obj = new ObjectStack();
        EvalPostfix evl = new EvalPostfix();
        Output out = new Output();
        System.out.println ("These are the infix statements.");
        //infix = keyboard.nextString();

        Scanner fileScan = new Scanner(new File("infix.txt"));
        while (fileScan.hasNext())
        {
            String buf = fileScan.nextLine();
            System.out.println(buf);
        }
        
        System.out.println ("These are the postfix equations.");
        
        
        System.out.println ("These are the postfix equations evaluated.");
        
        
        lw.close();
    }
}
/**
 * Translate infix to postfix.
 * 
 * @Quang Pham 
 * @2/21/13
 */

import java.util.*;
public class InfixToPostfix
{
    //stack class also containing the intopostfix method
  
    //InfixToPostfix inf = new InfixToPostfix(); 
    ObjectStack obj = new ObjectStack();
    //EvalPostfix evl = new EvalPostfix();
    
    int i,j;
    char postfix[];
    
        boolean isOperand(char ch)
        {
            if((ch>='a'&&ch<='z')||(ch>=0&&ch<='9'))
                return true;
            else 
                return false;

        }

        boolean isOperator(char ch)
        {
            if(ch=='+'||ch=='-'||ch=='*'||ch=='/')
                return true;
            else 
                return false;

        }

        void IntoPost(String str)
        {
            postfix = new char[str.length()];
            char ch;

            j=0;

            for(i=0;i<str.length();i++)
            {
                ch = str.charAt(i);
                if(ch=='(')
                    obj.push (ch);
                else if(isOperand(ch))
                {
                    postfix[j++]=ch;
                }
                else if(isOperator(ch))
                {
                    obj.push (ch);
                }
                else if(ch==')')
                {
                    //ch = obj.pop();
                    while (ch!= '(')
                    {
                        postfix[j++] = ch;
                        //ch = obj.pop();
                    }
                }
                //System.out.println (postfix[]);
            }

        }

        void disp()
        {
            for(i=0;i<postfix.length;i++)
            {   
                System.out.print(postfix[i]);
            }
        }
    }
/**
 * Evaluate postfix equation.
 * 
 * @Quang Pham
 * @2/21/13
 */
public class EvalPostfix
{
    //InfixToPostfix inf = new InfixToPostfix();
    ObjectStack obj = new ObjectStack();
    //EvalPostfix evl = new EvalPostfix();
    
    String str = "";
    char postfix[];
    int top;

    public int EvalPostfix(String Object[]) 
    {
        String Operand = "";
        String Operator = "";
        String ObjectStack = "";
        int number1 = 0;
        int number2 = 0;
        int result = 0;
        char ch;
        char postfix[];
        String str = "";
        postfix = new char[str.length()];

        for (int j = 0; j < str.length(); j++) 
        {
            ch = str.charAt(j);
            if (ch == (Integer)(number1)) 
            {
                obj.push(ch);
            } 
            else 
            {

                //number1 = obj.pop(); 
                //number2 = obj.pop();
                switch (ch) 
                {
                    case '+':
                    result = number1 + number2;
                    break;
                    case '-':
                    result = number1 - number2;
                    break;
                    case '*':
                    result = number1 * number2;
                    break;
                    case '/':
                    result = number1 / number2;
                    break;
                    case '%':
                    result = number1 % number2;
                    break;
                }
            }
        }

        return result;
    }

    public static void main(String[] args) 
    {
        ObjectStack obj = new ObjectStack(100);
        String y = new String("(z * j)/(b * 8) ^2");
        String x = new String("10 3 + 9 *");
        //TestingClass clas = new TestingClass(st);

        //clas.test(y);
        //System.out.println(ObjectStack.test(y));

        //clas.EvalPostfix(x);
    }

    public boolean isStackEmpty()
    {
        if (top == 0)
        {
            System.out.println("Stack is empty " + "Equation Good");
            return true;
        } else
            System.out.println("Equation is No good");
        return false;
    }

    public void reset()
    {
        top = -1;
    }

    public void showStack() 
    {
        System.out.println(" ");
        System.out.println("Stack Contents...");
        for (int j = top; j > -1; j--)
        {
            System.out.println(postfix[j]);
        }
        System.out.println(" ");
    }

    public void showStack0toTop()
    {
        System.out.println(" ");
        System.out.println("Stack Contents...");
        for (int j = 0; j >= top; j++) 
        {
            System.out.println(postfix[j]);
        }
        System.out.println(" ");
    }

}
/**
 * Object stack of equations.
 * 
 * @Quang Pham 
 * @12/21/13
 */
public class ObjectStack
{
    String ObjectStack;
    
    String ObjectStackInterface;

    private Object[] item;
    private int top;
    private int size;

    public ObjectStack()
    {
        size = 100;
        item = new Object[size];
        top = -1;
    }

    public ObjectStack(int max)
    {
        size = max;
        item = new Object[size];
        top = -1;
    }

    public boolean isEmpty()
    {
        return top == -1;
    }

    public boolean isFull()
    {
        return top == size-1;
    }

    public void clear()
    {
        top = -1;
    }

    public void push(Object x)
    {
        if (isFull()) 
        {
            System.out.println("Push Runtime Error: Stack Overflow");
            System.exit(1);
        }
        item[++top] = x;
    }

    public Object pop()
    {
        if (isEmpty())
        {
            System.out.println("Pop Runtime Error: Stack Underflow");
            System.exit(1);
        }
        return item[top--];
    }

    public Object top() 
    {
        if (isEmpty())
        {
            System.out.println("Top Runtime Error: Stack Underflow");
            System.exit(1);
        }
        return item[top];
    }

}

Do you know how to make it compile better and run better?

This is my improved InfixToPostfix Program.

/**
 * Driver to start execution of program.
 * 
 * @Quang Pham 
 * @2/21/13
 */
import java.io.*;

import java.util.Scanner;

public class Driver
{
    LineWriter lw;
    public Driver (LineWriter lw)
    {
        lw = new LineWriter("csis.txt");   
    }
    String infix = "";
    Scanner keyboard = new Scanner(System.in);

    public static void main(String[] args)throws IOException
    {
        LineWriter lw = new LineWriter("csis.txt");
        InfixToPostfix inf = new InfixToPostfix();
        //ObjectStack obj = new ObjectStack();
        EvalPostfix evl = new EvalPostfix();
        Output out = new Output();
        System.out.println ("These are the infix statements.");
        //infix = keyboard.nextString();

        Scanner fileScan = new Scanner(new File("infix.txt"));
        while (fileScan.hasNext())
        {
            String buf = fileScan.nextLine();
            System.out.println(buf);
        }
        
        System.out.println ("These are the postfix equations.");
        
        
        System.out.println ("These are the postfix equations evaluated.");
        
        
        lw.close();
    }
}
/**
 * Translate infix to postfix.
 * 
 * @Quang Pham 
 * @2/21/13
 */

import java.util.*;
public class InfixToPostfix
{
    //stack class also containing the intopostfix method
  
    //InfixToPostfix inf = new InfixToPostfix(); 
    ObjectStack obj = new ObjectStack();
    //EvalPostfix evl = new EvalPostfix();
    
    int i,j;
    char postfix[];
    
        boolean isOperand(char ch)
        {
            if((ch>='a'&&ch<='z')||(ch>=0&&ch<='9'))
                return true;
            else 
                return false;

        }

        boolean isOperator(char ch)
        {
            if(ch=='+'||ch=='-'||ch=='*'||ch=='/')
                return true;
            else 
                return false;

        }

        void IntoPost(String str)
        {
            postfix = new char[str.length()];
            char ch;

            j=0;

            for(i=0;i<str.length();i++)
            {
                ch = str.charAt(i);
                if(ch=='(')
                    obj.push (ch);
                else if(isOperand(ch))
                {
                    postfix[j++]=ch;
                }
                else if(isOperator(ch))
                {
                    obj.push (ch);
                }
                else if(ch==')')
                {
                    //ch = obj.pop();
                    while (ch!= '(')
                    {
                        postfix[j++] = ch;
                        //ch = obj.pop();
                    }
                }
                //System.out.println (postfix[]);
            }

        }

        void disp()
        {
            for(i=0;i<postfix.length;i++)
            {   
                System.out.print(postfix[i]);
            }
        }
    }
/**
 * Evaluate postfix equation.
 * 
 * @Quang Pham
 * @2/21/13
 */
public class EvalPostfix
{
    //InfixToPostfix inf = new InfixToPostfix();
    ObjectStack obj = new ObjectStack();
    //EvalPostfix evl = new EvalPostfix();
    
    String str = "";
    char postfix[];
    int top;

    public int EvalPostfix(String Object[]) 
    {
        String Operand = "";
        String Operator = "";
        String ObjectStack = "";
        int number1 = 0;
        int number2 = 0;
        int result = 0;
        char ch;
        char postfix[];
        String str = "";
        postfix = new char[str.length()];

        for (int j = 0; j < str.length(); j++) 
        {
            ch = str.charAt(j);
            if (ch == (Integer)(number1)) 
            {
                obj.push(ch);
            } 
            else 
            {

                //number1 = obj.pop(); 
                //number2 = obj.pop();
                switch (ch) 
                {
                    case '+':
                    result = number1 + number2;
                    break;
                    case '-':
                    result = number1 - number2;
                    break;
                    case '*':
                    result = number1 * number2;
                    break;
                    case '/':
                    result = number1 / number2;
                    break;
                    case '%':
                    result = number1 % number2;
                    break;
                }
            }
        }

        return result;
    }

    public static void main(String[] args) 
    {
        ObjectStack obj = new ObjectStack(100);
        String y = new String("(z * j)/(b * 8) ^2");
        String x = new String("10 3 + 9 *");
        //TestingClass clas = new TestingClass(st);

        //clas.test(y);
        //System.out.println(ObjectStack.test(y));

        //clas.EvalPostfix(x);
    }

    public boolean isStackEmpty()
    {
        if (top == 0)
        {
            System.out.println("Stack is empty " + "Equation Good");
            return true;
        } else
            System.out.println("Equation is No good");
        return false;
    }

    public void reset()
    {
        top = -1;
    }

    public void showStack() 
    {
        System.out.println(" ");
        System.out.println("Stack Contents...");
        for (int j = top; j > -1; j--)
        {
            System.out.println(postfix[j]);
        }
        System.out.println(" ");
    }

    public void showStack0toTop()
    {
        System.out.println(" ");
        System.out.println("Stack Contents...");
        for (int j = 0; j >= top; j++) 
        {
            System.out.println(postfix[j]);
        }
        System.out.println(" ");
    }

}
/**
 * Object stack of equations.
 * 
 * @Quang Pham 
 * @12/21/13
 */
public class ObjectStack
{
    String ObjectStack;
    
    String ObjectStackInterface;

    private Object[] item;
    private int top;
    private int size;

    public ObjectStack()
    {
        size = 100;
        item = new Object[size];
        top = -1;
    }

    public ObjectStack(int max)
    {
        size = max;
        item = new Object[size];
        top = -1;
    }

    public boolean isEmpty()
    {
        return top == -1;
    }

    public boolean isFull()
    {
        return top == size-1;
    }

    public void clear()
    {
        top = -1;
    }

    public void push(Object x)
    {
        if (isFull()) 
        {
            System.out.println("Push Runtime Error: Stack Overflow");
            System.exit(1);
        }
        item[++top] = x;
    }

    public Object pop()
    {
        if (isEmpty())
        {
            System.out.println("Pop Runtime Error: Stack Underflow");
            System.exit(1);
        }
        return item[top--];
    }

    public Object top() 
    {
        if (isEmpty())
        {
            System.out.println("Top Runtime Error: Stack Underflow");
            System.exit(1);
        }
        return item[top];
    }

}

Do you know how to make it compile better and run better?