servlet从服务器磁盘文件读出到浏览器显示，中文乱码问题，不要忘记在输入流和输出流都要设置编码格式，否则一个地方没设置不统一就会各种乱码

package com.swift;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/show")
public class fromJsonFile extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    public fromJsonFile() {
        super();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream("d:/student.json"),"utf-8"));//这里不要忘记设置编码
        String str;
        StringBuffer sb=new StringBuffer();
        while((str=br.readLine())!=null) {
            sb.append(str);
            sb.append("\r\n");
        }
        br.close();
        response.getWriter().println(sb.toString());
        System.out.println(sb.toString());
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}