Dear Sir ,
I am a beginner at java .It is my third program written for Student class .

I got it compiled normally , but am receiving a runtime exception .
It reads as :
Exception in the thread main
java. lang. NoSuchMethodError : main

I checked the code word by word , line by line , but I could not locate the error . Plz go through it and let me know where the error lies. ? Plz send me the code , if you need to modified it. Or let me know the steps , how should I proceed.

Code on Notepad as Java file :

/* 786 */
/* File Name Student.java */

public class Student {

private String name ;
private int rollNo ;

/* ***** Setters ****** */
public void setName ( String name){
this.name = name ;
}

/* ***** class lvel variable ***** */
public void setRollNo ( int rollNo ) {
if ( rollNo > 0 ) {
this.rollNo = rollNo ;
}
else {
this.rollNo = 100 ;
}
}

/* ***** standard getters ***** */
public String getName () {
return name ;
}

public int getRollNo () {
return rollNo ;
}

/* ***** Default constructor ***** */
public Student () {
name = " not set " ;
rollNo = 100 ;
}

/* ***** parameterized constructor for a new
student ***** */
public Student ( String name , int rollNo) {
setName (name) ;
setRollNo (rollNo) ;
}

/* ***** copy constructor for a new student ***** */
public Student ( Student s ) {
name = s.name ;
rollNo = s.rollNo ;
}

/* ***** method used to diplay on consol ***** */
public void print () {
System.out.print ( " Student name : " +name) ;
System.out.print ( " , roll no : " +rollNo) ;
}

} // ****** end of class


code ends here .


I have done as below :
Copied the code on notepad and saved as java file
Gave command < javac Student.java >
It worked / compiled successfully .
Gave command < java Student >
Got the Exception error.

Your help is solicited.
Thanks.

from rajinder singh:
dear frnd
u have not write the main fn in the class as:
public class Student {

private String name ;
private int rollNo ;

/* ***** Setters ****** */
public void setName ( String name){
this.name = name ;
}

/* ***** class lvel variable ***** */
public void setRollNo ( int rollNo ) {
if ( rollNo > 0 ) {
this.rollNo = rollNo ;
}
else {
this.rollNo = 100 ;
}
}

/* ***** standard getters ***** */
public String getName () {
return name ;
}

public int getRollNo () {
return rollNo ;
}

/* ***** Default constructor ***** */
public Student () {
name = " not set " ;
rollNo = 100 ;
}

/* ***** parameterized constructor for a new
student ***** */
public Student ( String name , int rollNo) {
setName (name) ;
setRollNo (rollNo) ;
}

/* ***** copy constructor for a new student ***** */
public Student ( Student s ) {
name = s.name ;
rollNo = s.rollNo ;
}

/* ***** method used to diplay on consol ***** */
public void print () {
System.out.print ( " Student name : " +name) ;
System.out.print ( " , roll no : " +rollNo) ;
}
//******************************
public static void main(String args[])
{
Student std=new Student("rajinder",25);
System.out.println(std.getName);//it will print ur name as rajinder
System.out.println(std.getRollNo);// it will print ur rollno 25

}
//*******************************

} // ****** end of class

: from rajinder singh:
: dear frnd
: u have not write the main fn in the class as:
: public class Student {
:
: private String name ;
: private int rollNo ;
:
: /* ***** Setters ****** */
: public void setName ( String name){
: this.name = name ;
: }
:
: /* ***** class lvel variable ***** */
: public void setRollNo ( int rollNo ) {
: if ( rollNo > 0 ) {
: this.rollNo = rollNo ;
: }
: else {
: this.rollNo = 100 ;
: }
: }
:
: /* ***** standard getters ***** */
: public String getName () {
: return name ;
: }
:
: public int getRollNo () {
: return rollNo ;
: }
:
: /* ***** Default constructor ***** */
: public Student () {
: name = " not set " ;
: rollNo = 100 ;
: }
:
: /* ***** parameterized constructor for a new
: student ***** */
: public Student ( String name , int rollNo) {
: setName (name) ;
: setRollNo (rollNo) ;
: }
:
: /* ***** copy constructor for a new student ***** */
: public Student ( Student s ) {
: name = s.name ;
: rollNo = s.rollNo ;
: }
:
: /* ***** method used to diplay on consol ***** */
: public void print () {
: System.out.print ( " Student name : " +name) ;
: System.out.print ( " , roll no : " +rollNo) ;
: }
: //******************************
: public static void main(String args[])
: {
: Student std=new Student("rajinder",25);
: System.out.println(std.getName);//it will print ur name as rajinder
: System.out.println(std.getRollNo);// it will print ur rollno 25
:
: }
: //*******************************
:
: } // ****** end of class
:
:
: ..................................................................
: Dear Rajinder ,
: It was pinching that I had not written the main function , but I was unable to compose , what should I write there. The print function had already been called in prevoious line , and I did not know what alse to write.
: But I hope it will work now . I will let you know , hopefully by tomorrow evening. Presently I am stuck with an assignment on computer graphics.

Many thanks again.