SpringMVC数据传递及乱码问题

基础环境搭建请参考SringMVC入门程序

一、SpringMVC数据处理

1：resful 路径传值

http://localhost/get/1/2

/*  http://localhost/get/1/2  */
/*路径传值 必须要用@PathVariable*/
@GetMapping("/get/{id1}/{id2}")
public String getValue(@PathVariable String id1, @PathVariable String id2, Model model){
    String msg = id1 + id2;
    model.addAttribute("msg",msg);
    return "hello";
}

2：参数传值：参数名一致

http://localhost/get2?id=applesnt

 @GetMapping("/get2")
 public String getValue2(String id,Model model){
     model.addAttribute("msg",id);
     return "hello";
 }

3：参数传值：参数名不一致

http://localhost/get3?username=134

 @GetMapping("/get3")
 public String getValue3(@RequestParam("username") String name, Model model){
     model.addAttribute("msg",name);
     return "hello";
 }

4：对象传值：UserVo

http://localhost/get4?id=111&name=zhangsan&age=12

@GetMapping("/get4")
public String getValue4(UserVo userVo, Model model){
    model.addAttribute("msg",userVo.toString());
    return "hello";
}

二、SpringMVC乱码处理

1：编写filter乱码过滤器

com\applesnt\filter\GenericEncodingFilter.java

package com.applesnt.filter;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Map;

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

    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

        //处理response的字符编码
        HttpServletResponse myResponse=(HttpServletResponse) response;
        myResponse.setContentType("text/html;charset=UTF-8");

        // 转型为与协议相关对象
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        // 对request包装增强
        HttpServletRequest myrequest = new MyRequest(httpServletRequest);
        chain.doFilter(myrequest, response);

    }

    public void destroy() {

    }

    //自定义request对象，HttpServletRequest的包装类
    class MyRequest extends HttpServletRequestWrapper {

        private HttpServletRequest request;
        //是否编码的标记
        private boolean hasEncode;

        //定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰
        public MyRequest(HttpServletRequest request) {
            super(request);// super必须写
            this.request = request;
        }

        // 对需要增强方法 进行覆盖
        @Override
        public Map getParameterMap() {
            // 先获得请求方式
            String method = request.getMethod();
            if (method.equalsIgnoreCase("post")) {
                // post请求
                try {
                    // 处理post乱码
                    request.setCharacterEncoding("utf-8");
                    return request.getParameterMap();
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
            } else if (method.equalsIgnoreCase("get")) {
                // get请求
                Map<String, String[]> parameterMap = request.getParameterMap();
                if (!hasEncode) { // 确保get手动编码逻辑只运行一次
                    for (String parameterName : parameterMap.keySet()) {
                        String[] values = parameterMap.get(parameterName);
                        if (values != null) {
                            for (int i = 0; i < values.length; i++) {
                                try {
                                    // 处理get乱码
                                    values[i] = new String(values[i]
                                            .getBytes("ISO-8859-1"), "utf-8");
                                } catch (UnsupportedEncodingException e) {
                                    e.printStackTrace();
                                }
                            }
                        }
                    }
                    hasEncode = true;
                }
                return parameterMap;
            }
            return super.getParameterMap();
        }

        //取一个值
        @Override
        public String getParameter(String name) {
            Map<String, String[]> parameterMap = getParameterMap();
            String[] values = parameterMap.get(name);
            if (values == null) {
                return null;
            }
            return values[0]; // 取回参数的第一个值
        }

        //取所有值
        @Override
        public String[] getParameterValues(String name) {
            Map<String, String[]> parameterMap = getParameterMap();
            String[] values = parameterMap.get(name);
            return values;
        }
    }
}

2：配置web.xml 注册filter

<?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">

    <!--注册乱码过滤器-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.applesnt.filter.GenericEncodingFilter</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>


    <!--1.注册DispatcherServlet-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--关联一个springmvc的配置文件:【servlet-name】-servlet.xml-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc-servlet.xml</param-value>
        </init-param>
        <!--启动级别-1-->
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!--/ 匹配所有的请求；（不包括.jsp）-->
    <!--/* 匹配所有的请求；（包括.jsp）-->
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

3：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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <context:component-scan base-package="com.applesnt.controller"/>

    <!-- 让Spring MVC不处理静态资源 -->
    <mvc:default-servlet-handler />

    <!--annotation-driven配置帮助我们完成处理器映射器和处理器适配器-->
    <mvc:annotation-driven />

    <!--视图解析器:DispatcherServlet给他的ModelAndView-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="prefix" value="/WEB-INF/jsp/"/>

        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

4：编写form表单提交测试乱码

web\form.jsp

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

<form action="/getform" method="post">
    <input type="text" name="name">
    <input type="submit" value="乱码测试">
</form>
</body>
</html>

5：编写controller返回的视图页面

web\WEB-INF\jsp\hello.jsp

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

6：编写controller

com\applesnt\controller\HelloController3.java

package com.applesnt.controller;

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

@Controller
public class HelloController3 {

    @PostMapping("/getform")
    public String getForm(String name,Model model){
        model.addAttribute("msg",name);
        return "hello";
    }
}

7：测试