前端显示汉字乱码

前端显示乱码问题的解决方法，两种方案：自定义过滤器；使用springmvc给的过滤器

自定义过滤器

package com.zkw.filter;

import javax.servlet.*;
import java.io.IOException;

public class EncodingFilter implements Filter {
    
    
    public void init(FilterConfig filterConfig) throws ServletException {
    
    

    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    
    
        servletRequest.setCharacterEncoding("UTF-8");
        servletResponse.setCharacterEncoding("UTF-8");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    public void destroy() {
    
    

    }
}

配置web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    
    <!--注册DispatcherServlet 本质就是一个servlet-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <!--加载springmvc-servlet.xml文件-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc-servlet.xml</param-value>
        </init-param>

        <!--配置web.xml文件的启动级别-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    
    <!--2.自定义编码过滤器-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.zkw.filter.EncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <!--这里必须是/* 表示可以过滤所有的请求包括.jsp-->
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <!--3.使用springmvc给定的过滤器-->
  <!--  <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>-->
</web-app>

springmvc-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--扫描特定包下的注解-->
    <context:component-scan base-package="com.zkw.restful"/>
    <!--过滤静态资源-->
    <mvc:default-servlet-handler/>
    <!--mvc注解驱动-->
    <mvc:annotation-driven/>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
    <!--前缀-->
    <property name="prefix" value="/WEB-INF/jsp/"/>
    <!--后缀-->
    <property name="suffix" value=".jsp"/>
</bean>
</beans>

来一个Controller

package com.zkw.restful;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class EncodingController {
    
    

    @PostMapping("/encoding/t1")
    public String test1(@RequestParam("username") String name, Model model){
    
    
        model.addAttribute("msg",name);
        return "test";
    }
}

再来一个jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
${msg}
</body>
</html>

结果为