SpringMVC中乱码问题的解决配置filter乱码过滤器

第一种 在web.xml中配置 SpringMVC 的乱码过滤器

    <filter>
        <filter-name>encodingfilter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
        <init-param>
            <param-name>encodingparam-name>
            <param-value>utf-8param-value>
        init-param>
    filter>
    <filter-mapping>
        <filter-name>encodingfilter-name>
        <url-pattern>/*url-pattern>
    filter-mapping>

第二种 自定义乱码过滤器

1. 编写乱码过滤器的类

package com.pro.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 {
     

    @Override
    public void destroy() {
     
    }

    @Override
    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);
    }

    @Override
    public 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
    @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. 在web.xml中配置 filter

<filter>
    <filter-name>encodingfilter-name>
    <filter-class>com.pro.filter.GenericEncodingFilterfilter-class>
filter>
<filter-mapping>
    <filter-name>encodingfilter-name>
    <url-pattern>/*url-pattern>
filter-mapping>