Servlet輸出不亂碼

程式如下

package newpackage;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class NewServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        String userInput = new String(request.getParameter("userInput").getBytes("UTF-8"));
        out.print(userInput);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.print("哈囉");
    }

}

不管是POST還是GET第一行都要先放response.setContentType("text/html;charset=UTF-8");這行
如果是GET，要先把在網址列取得的參數用getBytes取得並轉成UTF-8，之後才輸出。可以上方的程式碼。

最近又發生亂碼的情況了，看來還有別的會亂碼的情況我沒注意到
就是我從jsp送post請求給servlet，servlet再把這個從jsp送來的參數顯示到另一個jsp
我在servlet用System.out.println()查看這個參數，才發現進到servlet時就亂碼了，所以應該不是jsp的問題

後來我在servlet的doPost的第二行加入request.setCharacterEncoding("UTF-8");
就解決了

原本以為