public static void main(String [] args)
    {
        String str="asd123 dgw35df wi13gdf9";
        StringBuffer strb;
        
        int sum=0;
    
    int len = str.length();
    //char ch ;
    for(int i=0;i<len;i++)
    {
        strb = new StringBuffer();
        while(Character.isDigit(str.charAt(i)))
        {
            //System.out.println(i);
            strb = strb.append(str.charAt(i));
            i++;
            if(i==len) 
            {
                break;
            }
        }
    
        String ggg =strb.toString();
        
        int aaa = Integer.parseInt(ggg);
        System.out.println("=="+aaa);
        
            
    }
    System.out.println("The total is "+ sum);
    
    }

// OUTPUT is...
Exception in thread "main" java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at interview_Programs.Thermofisher_program.main(Thermofisher_program.java:33)

yes i tried with converting to string the converting to integer.
By using Integer.ParseInt();
But it is not workng..

I need to convert from Strinbuffer to Integer value to perform the operation…