What kind of java code is defined as one thread by JVM?

Question

I know the definition of thread....
My teacher told me that normally, the java program run from the code from the first line to the end in order....
but somethimes, in main() method, the method does not run in sequence as I expected, and I thought that actually each method is 1 thread, but when I start using a method like finalize(), even sometimes the code inside it is also not in sequence....
so can any one help me on the question stated on my topic?
Secondly, can any one find any article or doc that tells me about the behavior of JVM on choosing the sequence of threads, so I know whether I should use thread method to set priority in need.....[/b[
thx

Answer 1

class Chair{
     public static int created = 0;
     public static boolean t = true;
     public int i;
     public Chair(){
          created++;
          i = created;
          //System.out.println(" i number is" + " " + i);
public void finalize(){
     if ( i > 10000){
          t = false;}
     System.out.println("Finalizing Chair object number: " + i + " .");
public class Garbage{
     public static void main(String args[]){
          System.out.println("Start finalizing 10 Chair objects");
          System.out.println();
          while(Chair.t){
               new Chair();
               /*if(Chair.i > 2000){
          Chair.t = false;
          /*for(int i = 0 ; i < 10000 ; i++){
               new Chair();
          /*Chair a = new Chair();
          a.Chair();     
}I was expecting that the JVM stops making Chair objects after Chair No 10000, but the result turns that JVM make more than 10000 objects.....