本文主要是介绍【WEEK3】 【DAY1】数据处理及跳转之乱码问题【中文版】,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
2024.3.11 Monday
接上文 【WEEK2】 【DAY5】数据处理及跳转之数据处理【中文版】
目录
- 5.3.乱码问题
- 5.3.1.在首页编写一个提交的表单
- 5.3.2.后台编写对应的处理类
- 5.3.3.修改springmvc-controller.xml
- 5.3.4.运行
- 5.3.5.解决乱码
- 5.3.5.1.Servlet(无法解决)
- 5.3.5.2.使用过滤器
- 1. 自定义filter
- 2. 修改web.xml(添加以下代码)
- 3. 直接使用官方提供的过滤器
- 5.3.5.3.乱码的总结部分
5.3.乱码问题
5.3.1.在首页编写一个提交的表单
在web->新建form.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>FromEncodingController</title>
</head>
<body>
<%--以post方式提交--%>
<form action="/springmvc_04_controller_war_exploded/EC/t1" method="post"><input type="text" name="name"><input type="submit">
</form>
</body>
</html>
5.3.2.后台编写对应的处理类
Controller->新建EncodingController.java
package com.kuang.controller;import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PostMapping;@Controller
public class EncodingController {@PostMapping("/EC/t1")public String test1(String name, Model model){System.out.println(name);model.addAttribute("msg",name);//这里name千万不能用双引号,否则页面传入的字符永远是name而非用户输入的内容return "test";}
}
5.3.3.修改springmvc-controller.xml
取消注释
5.3.4.运行
http://localhost:8080/springmvc_04_controller_war_exploded/form.jsp
点击提交后产生乱码
http://localhost:8080/springmvc_04_controller_war_exploded/EC/t1
5.3.5.解决乱码
5.3.5.1.Servlet(无法解决)
package com.kuang.controller;import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PostMapping;import javax.servlet.http.HttpServletRequest;
import java.io.UnsupportedEncodingException;@Controller
public class EncodingController {@PostMapping("/EC/t1")public String test1(String name, Model model, HttpServletRequest request)throws UnsupportedEncodingException {request.setCharacterEncoding("utf-8"); //此方法无用->用过滤器解决乱码System.out.println(name);model.addAttribute("msg",name);//这里name千万不能用双引号,否则页面传入的字符永远是name而非用户输入的内容return "test";}
}
5.3.5.2.使用过滤器
1. 自定义filter
- 新建EncodingFilter.java
选择javax.servlet类型的Filter导入
package com.kuang.filter;import javax.servlet.*;
import java.io.IOException;public class EncodingFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {servletRequest.setCharacterEncoding("utf-8");servletResponse.setCharacterEncoding("utf-8");filterChain.doFilter(servletRequest,servletResponse);//写完过滤器去配置文件web.xml注册}@Overridepublic void destroy() {}
}
2. 修改web.xml(添加以下代码)
<!-- filter --><filter><filter-name>encoding</filter-name><filter-class>com.kuang.filter.EncodingFilter</filter-class></filter><filter-mapping><filter-name>encoding</filter-name><url-pattern>/*</url-pattern></filter-mapping>
- 或直接使用已有的非官方过滤器(效果最强)
package com.kuang.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;/**
* 解决get和post请求 全部乱码的过滤器
*/
public class GenericEncodingFilter implements Filter {@Overridepublic void destroy() {}@Overridepublic 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);}@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}}//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@Overridepublic 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@Overridepublic 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@Overridepublic String[] getParameterValues(String name) {Map<String, String[]> parameterMap = getParameterMap();String[] values = parameterMap.get(name);return values;}
}
3. 直接使用官方提供的过滤器
- 仅修改web.xml即可,无需新建filter相关文件
<?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"><!--1.配置DispatcherServlet--><servlet><servlet-name>SpringMVC</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!--通过初始化参数指定SpringMVC配置文件的位置,进行关联--><init-param><param-name>contextConfigLocation</param-name><!-- 配置文件的位置,是在resource文件夹下的文件名 --><param-value>classpath:springmvc-controller.xml</param-value><!-- 这里仍然需要配置springmvc-controller.xml文件 --></init-param><!-- 启动顺序,数字越小,启动越早 --><load-on-startup>1</load-on-startup></servlet><!--所有请求都会被springmvc拦截 --><servlet-mapping><servlet-name>SpringMVC</servlet-name><url-pattern>/</url-pattern></servlet-mapping><!-- filter --><filter><filter-name>encoding</filter-name>
<!-- <filter-class>com.kuang.filter.EncodingFilter</filter-class> <!–一般情况下不使用自己书写的过滤器(本行)–>--><!--使用官方的即可(把自定义的第32行改成如下34~38行)--><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>
- 运行
http://localhost:8080/springmvc_04_controller_war_exploded/form.jsp
点击提交后会产生乱码的问题被解决:
http://localhost:8080/springmvc_04_controller_war_exploded/EC/t1
5.3.5.3.乱码的总结部分
- 一般情况下,SpringMVC默认的乱码处理就已经能够很好的解决了
- 然后在web.xml中配置这个过滤器即可(无论是自定义的还是官方的都需要配置)
- 乱码问题,需要平时多注意,在尽可能能设置编码的地方,都设置为统一编码 UTF-8
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