package 模拟去掉字符串两端的空格;

import java.util.Scanner;
class trim1{
    String str=null;
    public trim1(String str){
        this.str=str;
        int count1=leftTrim();
        int count2=rightTrim();
        str.substring(count1, count2+1);
        System.out.println(str);
    }
    int leftTrim(){
        int i=0;
        while(true){
            if(str.charAt(i)==" ")
                i++;
            else
                break;
        }
        return i;
    }
    int rightTrim(){
        int leng=str.length();
        while(true){
            if(str.charAt(leng)==" ")
                leng--;
            else
                break;
        }
        return leng;
    }
   
   
   
}
public class Trim {
    public static void main(String[] args){
        String str=null;
        System.out.println("请输入字符串");
        Scanner scan=new Scanner(System.in);
        str=scan.nextLine();
        new trim1(str);
        
    }
   

}




Exception in thread "main" java.lang.Error: Unresolved compilation problem:
    Incompatible operand types char and String

    at 模拟去掉字符串两端的空格.trim1.leftTrim(Trim.java:16)
    at 模拟去掉字符串两端的空格.trim1.<init>(Trim.java:8)
    at 模拟去掉字符串两端的空格.Trim.main(Trim.java:43)