Regarding Code competition quesion!

Question

I came across a Code competition quesion and i have done it.
But i haven't got any idea to how to validate the inputs(Checking whether the inputs are string or not!!!!!!!!!!!)
the following is my code:
import java.io.*;
class cup
     int length,width,height;
     String name;
     cup()                    //default Constructer
          length=0;
          width=0;
          height=0;
          name=" ";
     cup(String n,int l,int w,int h) //Constructer with 4 parameters
          length=l;
          width=w;
          height=h;
          name=n;
     int getvolume()
          return length*width*height; //Calculate the volume of every Cup
public class jelly
     static int no;
     static cup a[];
     static String part[];
     public static void main(String args[])
          System.out.println("Enter no of cups and details:");
          getsize();
          if(no>0)
               cal();     
               while(no!=0){
                    System.out.println("Enter no of cups and details or enter 0 to exit:");
                    getsize();
                    if(no>0)
                         cal();     
     static void cal()
          cup min,max;
          a=new cup[no];
               for(int i=0;i<no;i++)
                    a=getcup();
               min=max=a[0];
               for(int k=1;k<no;k++)
                    if(min.getvolume()>a[k].getvolume())
                         min=a[k];
                    else if(max.getvolume()<a[k].getvolume())
                         max=a[k];
                    if(min.equals(max))
                         System.out.println("No Child Has Lost Jelly!");
                    else
                         System.out.println(min.name+" has lost jelly to "+max.name);
     static void getsize()
     try     
          DataInputStream in=new DataInputStream(System.in);
          String no1=in.readLine();                         //Get The number of cups
          no=validateno(no1);
     catch (Exception e)
     static cup getcup()
     try
          DataInputStream in=new DataInputStream(System.in);
          String tot=in.readLine();
          String na=" ";
          String le=" ";
          String wi=" ";
          String hi=" ";
          int k,l,w,h;
          String ar[]=tot.split(" ");
          na=ar[0];
          le=ar[1];
          wi=ar[2];
          hi=ar[3];
          l=Integer.parseInt(le);
          w=Integer.parseInt(wi);
          h=Integer.parseInt(hi);
     cup c=new cup(na,l,w,h);
          return c;
     catch (Exception e)
          return null;
     static int validateno(String n)
          int n_stud;
          try{
          n_stud=Integer.parseInt(n);
          catch(Exception e)
               System.out.println("Enter numerical value!");
               return -1;
          if(n_stud>100||n_stud<0)
               System.out.println("Enter no between 0 and 100!");
               return -1;
          return n_stud;
/*********I just want to add the following SIMILAR code with out making a error:***********/
static int validate_name(String n)
          if(n.length()>10)
               System.out.println("Enter a name less than 10 characters!");
               return -1;
          return 0;
CAN ANYONE GIVE ME A ANSWER??????????????????????!
BY THE WAY WHEN I COMPILED MY CODE IT GIVES ME A WARNING
CAN ANYONE GIVE ME A ANSWER??????????????????????

Answer 1

I came across a Code competition quesion and i have done it.
But i haven't got any idea to how to validate the inputs(Checking whether the inputs are string or not!!!!!!!!!!!)
the following is my code:
import java.io.*;
class cup
     int length,width,height;
     String name;
     cup()                               //default Constructer
          length=0;
          width=0;
          height=0;
          name=" ";
     cup(String n,int l,int w,int h)           //Constructer with 4 parameters
          length=l;
          width=w;
          height=h;
          name=n;
     int getvolume()
          return length*width*height;      //Calculate the volume of every Cup
public class jelly
     static int no;
     static cup a[];
     static String part[];
     public static void main(String args[])
          System.out.println("Enter no of cups and details:");
          getsize();
          if(no>0)
               cal();     
               while(no!=0){
                    System.out.println("Enter no of cups and details or enter 0 to exit:");
                    getsize();
                    if(no>0)
                         cal();     
     static void cal()
          cup min,max;
          a=new cup[no];
               for(int i=0;i<no;i++)
                    a=getcup();
               min=max=a[0];
               for(int k=1;k<no;k++)
                    if(min.getvolume()>a[k].getvolume())
                         min=a[k];
                    else if(max.getvolume()<a[k].getvolume())
                         max=a[k];
                    if(min.equals(max))
                         System.out.println("No Child Has Lost Jelly!");
                    else
                         System.out.println(min.name+" has lost jelly to "+max.name);
     static void getsize()
     try     
          DataInputStream in=new DataInputStream(System.in);
          String no1=in.readLine();                         //Get The number of cups
          no=validateno(no1);
     catch (Exception e)
     static cup getcup()
     try
          DataInputStream in=new DataInputStream(System.in);
          String tot=in.readLine();
          String na=" ";
          String le=" ";
          String wi=" ";
          String hi=" ";
          int k,l,w,h;
          String ar[]=tot.split(" ");
          na=ar[0];
          le=ar[1];
          wi=ar[2];
          hi=ar[3];
          l=Integer.parseInt(le);
          w=Integer.parseInt(wi);
          h=Integer.parseInt(hi);
     cup c=new cup(na,l,w,h);
          return c;
     catch (Exception e)
          return null;
     static int validateno(String n)
          int n_stud;
          try{
          n_stud=Integer.parseInt(n);
          catch(Exception e)
               System.out.println("Enter numerical value!");
               return -1;
          if(n_stud>100||n_stud<0)
               System.out.println("Enter no between 0 and 100!");
               return -1;
          return n_stud;
/*********I just want to add the following SIMILAR code with out making a error:***********/
static int validate_name(String n)
          if(n.length()>10)
               System.out.println("Enter a name less than 10 characters!");
               return -1;
          return 0;
CAN ANYONE GIVE ME A ANSWER??????????????????????!
BY THE WAY WHEN I COMPILED MY CODE IT GIVES ME A WARNING
CAN ANYONE GIVE ME A ANSWER??????????????????????