1.方式一（使用传统的Spring提供的字符集过滤器）

先写一个Servlet。

package com.songzihao.springboot.servlet;

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

/**
 *
 */
@WebServlet(urlPatterns = "/myservlet")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println("世界你好，Hello World！！！");
        //统一设置浏览器编码格式
        resp.setContentType("text/html;character=utf-8");
        resp.getWriter().flush();
        resp.getWriter().close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

之后创建配置类 SystemConfig，在其中声明字符集过滤器的相关配置。

package com.songzihao.springboot.config;

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.filter.CharacterEncodingFilter;

/**
 *
 */
@Configuration
public class SystemConfig {

    @Bean
    public FilterRegistrationBean characterEncodingFilterRegistrationBean() {
        //创建字符集编码过滤器
        CharacterEncodingFilter characterEncodingFilter=new CharacterEncodingFilter();
        //设置强制使用指定的字符集编码
        characterEncodingFilter.setForceEncoding(true);
        //设置指定的字符集编码
        characterEncodingFilter.setEncoding("utf-8");

        FilterRegistrationBean filterRegistrationBean=new FilterRegistrationBean();
        //设置字符集编码过滤器
        filterRegistrationBean.setFilter(characterEncodingFilter);
        //设置字符集编码过滤器的路径
        filterRegistrationBean.addUrlPatterns("/*");
        return filterRegistrationBean;
    }
}

在SpringBoot核心配置文件中 关闭 SpringBoot 的 的 http 字符编码支持。

#关闭springboot的http字符编码支持
#只有关闭该选项之后，spring字符集编码过滤器才会生效
server.servlet.encoding.enabled=false

最后启动测试。

package com.songzihao.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@SpringBootApplication
@ServletComponentScan(basePackages = "com.songzihao.springboot.servlet")
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

---

2.方式二（在 application.properties 中配置字符编码（推荐））

先写一个Servlet。

package com.songzihao.springboot.servlet;

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

/**
 *
 */
@WebServlet(urlPatterns = "/myservlet")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println("世界你好，Hello World！！！");
        //统一设置浏览器编码格式
        resp.setContentType("text/html;character=utf-8");
        resp.getWriter().flush();
        resp.getWriter().close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

在 SpringBoot 核心配置文件添加字符编码设置。

#设置请求响应的字符编码
server.servlet.encoding.enabled=true
server.servlet.encoding.force=true
server.servlet.encoding.charset=utf-8

最后启动测试。

package com.songzihao.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@SpringBootApplication
@ServletComponentScan(basePackages = "com.songzihao.springboot.servlet")
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}