Exception in thread "main" java.lang.NoSuchMethodError: main - how can I fix that?

Question

Possible Duplicate:
Causes of 'java.lang.NoSuchMethodError: main Exception in thread “main”'

I am using Eclipse. I deleted everything and left the main function - nothing is working. Can somebody pls help?

package good;

import java.io.*;

public class FiFo {     
    public static void main()
    {
        System.out.println("here");
    }
}    

class FileReader {
    public FileReader(String fileName)
    {
        try {
            FileInputStream fstream = new FileInputStream(fileName);
            BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
        }
        catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

The main function should have a signature like:

public static void main( String[] args )
{
   // stuff ...
}

You've missed out the String array. When you run the program it expects to find a method with this signature, not the empty arg list you have in your sample code.

Answer 2

from the java docs:

Exception in thread "main" java.lang.NoSuchMethodError: main

The Java VM requires that the class you execute with it have a main method at which to begin execution of your application.

so it's probably the wrong main signature, as stated in the first post

Answer 3

import java.util.*;
import java.io.*;
import java.lang.*;

public class Run
{
    static BufferedReader nhap = new BufferedReader(new InputStreamReader(System.in));

    public Run()
    {
    }

    public static void main(String[] args) throws Exception
    {   
        int chon;
        System.out.println("1. Nhap Sinh Vien");
        System.out.println("2. Nhap Giao Vien");
        System.out.println("=> Moi ban chon 1 hoac 2 de nhap lieu");
        chon = Integer.parseInt(nhap.readLine());

        switch (chon)
        {   
            case 1:
            {
                System.out.print("So luong sinh vien can nhap vao: ");
                int SoSV = Integer.parseInt(nhap.readLine());
                System.out.print("=> Test  :  " + SoSV );
                SinhVien[] SV = new SinhVien[SoSV];
                int i;
                for (i = 0; i < SV.length; i++);
                {
                    System.out.printf("Nhap thong tin Sinh vien thu %d \n ", i + 1);
                    SV[i] = new SinhVien();
                    AddSV(SV[i]);
                }
            }
            case 2:
            {   
            }
            default: System.out.println("Lua chon cua ban khong co trong danh sach !");
        }   
    }

    public static void AddGV(GiaoVien gv) throws Exception
    {
        try
        {
            System.out.println("Nhap ma Giao vien: ");
            int ma = Integer.parseInt(nhap.readLine());
            System.out.print("Nhap ho ten giao vien ");
            gv.setHoten(nhap.readLine());
            System.out.print("Nhap tuoi giao vien");
            int tuoi = Integer.parseInt(nhap.readLine());
            System.out.print("Nhap ten khoa giao vien dang day");
            gv.setTenKhoa(nhap.readLine());
            System.out.print("Nhap chuyen nganh giao vien day");
            gv.setChuyenNganh(nhap.readLine());
            System.out.print("Nhap vao Mon giao vien day");
            gv.setMonDay(nhap.readLine());
        }
        catch(Exception ex)
        {   
            throw new Exception (ex.getMessage());
        }
    }

    public static void AddSV(SinhVien sv) throws Exception
    {
        try
        {   
            System.out.println("Nhap ma Sinh vien: ");
            int ma = Integer.parseInt(nhap.readLine());
            System.out.print("Nhap ho ten Sinh vien ");
            sv.setHoten(nhap.readLine());
            System.out.print("Nhap tuoi Sinh vien ");
            int tuoi = Integer.parseInt(nhap.readLine());
            System.out.print("Nhap ten khoa Sinh vien dang hoc");
            sv.setTenKhoa(nhap.readLine());
            System.out.print("Nhap Khoa sinh vien dang hoc");
            sv.setKhoaHoc(nhap.readLine());
            System.out.print("Nhap vao Lop Sinh vien hoc");
            sv.setLop(nhap.readLine());
        }
        catch(Exception ex)
        {
            throw new Exception (ex.getMessage());
        }
    }

    public static void OutPutSV(SinhVien sv) throws Exception
    {
        try
        {
            sv.Tostring();
        }
        catch(Exception ex)
        {   
            throw new Exception(ex.getMessage());
        }
    }

    public static void OutPuttGV(GiaoVien gv) throws Exception
    {
        try
        {
            gv.Tostring();
        }
        catch(Exception ex)
        {   
            throw new Exception (ex.getMessage());
        }
    }    
}

Answer 4

 public static void main()  // not correct signature for main

Answer 5

If you're using Eclipse, you need to make sure that you "Run As" a "Java Application".