what does the task mean，i can't understand，plz help me
public static void main(String[] args) throws Exception {
try{
method1();
}catch(NullPointerException e){
System.out.println("1");
}catch(FileNotFoundException e){
System.out.println("2");
}
}package zh.codegym.task.task09.task0913;
import java.io.FileNotFoundException;
import java.net.URISyntaxException;
/*
异常只捕获异常。
*/
public class Solution {
public static void main(String[] args) throws Exception {
//在此编写你的代码
method1();
//在此编写你的代码
}
public static void method1() throws NullPointerException, ArithmeticException, FileNotFoundException, URISyntaxException {
int i = (int) (Math.random() * 4);
if (i == 0)
throw new NullPointerException();
if (i == 1)
throw new ArithmeticException();
if (i == 2)
throw new FileNotFoundException();
if (i == 3)
throw new URISyntaxException("", "");
}
}