SpringMVC中乱码问题的解决配置filter乱码过滤器

心已赠人 2021-09-21 16:04 413阅读 0赞

## 第一种 在web.xml中配置 SpringMVC 的乱码过滤器 ##

<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>

## 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;
        }
    }

1.  在web.xml中配置 filter

<filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.pro.filter.GenericEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>