Reverse Each Word of Sentence

import java.util.*;
public class ReverseSentenceWord
{
    public static void main(String args[])
    {
        String str="",nstr="",wrd="";
        char ch=' ';
        int l=0;
        Scanner sc=new Scanner(System.in);
        System.out.print("Enter a sentence: ");
        str=sc.nextLine();
        str=str.trim()+" ";
        l=str.length();
        for(int i=0;i<l;i++)
        {
            ch=str.charAt(i);
            if(ch==' ')
            {
                nstr=nstr+wrd+' ';
                wrd="";
            }
            else
            {
                wrd=ch+wrd;
            }
        }
        System.out.println("New string: "+nstr);
    }
}