Java servlet encoding problem

I'm a beginner at Servlet.

Today I'm studying servlet encoding.

I encountered a garbled character while creating a string from a byte string.

OS: fedora28
jdk —java10
server:tomcat9
IDE:eclipse 4.8

Here's the source code:

servlet:

package getBytes_fun;
import java.io.IOException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RequestSample2 extensions HttpServlet{
    private static final long serialVersionUID = 1L;

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse)
 *      response)
 */

    protected void doGet (HttpServletRequest request, HttpServletResponse response)
        US>throws ServletException, IOException {
    // TODO Auto-generated method stub
        response.setContentType("text/html; charset=UTF-8";
        response.getWriter().append("Served at:").append(request.getContextPath());
        PrintWriter out=response.getWriter();

        String tmp;
        String name="";

        tmp = request.getParameter("name");
        if(tmp==null||tmp.length()==0){
            name = "Unconfigured";
        } else{
            name = decodeString(tmp);
        }

        intold;
        tmp = request.getParameter("old");
        if(tmp==null||tmp.length()==0){
            old = -1;
        } else{
            try{
                old = Integer.parseInt(tmp);
            } catch(NumberFormatExceptione){
                // TODO:handle exception
                old = -1;
            }
        }

        String tmps[] = request.getParameterValues("food");
        String food="";
        if(tmps!=null){
            for(inti=0;i<tmps.length;i++){
                food+=decodeString(tmps[i]);
                food+="";
            }
        } else{
            food = "No";
        }

        StringBuffersb = new StringBuffer();

        sb.append("<html>");
        sb.append("<head>");
        sb.append("<title>Sample</title>");
        sb.append("</head>");
        sb.append("<body>");

        sb.append("<p>What's your name?");
        sb.append(name);
        sb.append("is </p>");

        sb.append("<p>age is ");
        if(old==-1){
            sb.append("Not Configured </p>");
        } else{
            sb.append(old);
            sb.append("is </p>");
        }

        sb.append("<p>Favorite fruit is");
        sb.append(food);
        sb.append("is </p>");
        sb.append("</body>");
        sb.append("</html>");

        out.println(new String(sb));

        out.close();
    }

    protected String decodeString(String str) {
        // TODO Auto-generated method stub
        try{
            byte[] byteData=str.getBytes("ISO_8859_1");
            str = new String (byteData, "UTF-8");
        } catch(Exceptione){
            // TODO:handle exception
            return null;
        }
        return str;
    }
}

html file:

<!DOCTYPE html>
<html>
<head>
<metacharset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<p>Questionnaire Survey</p>
<form action="/ERP/RequestSample2" method="get">
    <table>
        <tr>
            <td>Name</td>
            <td><input type="text" size="20" value="name="name"></td>
        </tr>
        <tr>
            <td>Age</td>
            <td><input type="text" size="5" value="name="old"></td>
        </tr>
        <tr>
            <td>Favorite Fruits</td>
            <td><select name="food" size="3" multiple>
                    <option value="Apple">Apple</option>
                    <option value="melon">melon</option>
                    <option value="wine">wine</option>
            </select></td>
        </tr>
    </table>
    <input type="submit" name="button1" value="send">
</form>

Printout Results: