乱码解决SpringMVC

最新推荐文章于 2021-11-22 17:16:34 发布

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本文提供了一种通过自定义过滤器解决Web应用中GET和POST请求中文乱码的方法，包括实现自定义过滤器的代码示例及在web.xml中的配置方式，适用于Java Web开发。

Git解决方法
1、自定义过滤器

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() {

    }
}

2、web.xml配置

<!--配置过滤器-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.he.filter.EncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/</url-pattern>
    </filter-mapping>

如果用get请求时出现乱码，可以再项目管理窗口找到Servers，并打开里边的server.xml文件
在这里插入图片描述
第二种方式
web.xml文件配置

<!--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>

终极大招自定义过滤器

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

/**
  * 通用解决 get 和 post乱码过滤器
  */
public class EncodingFilter implements Filter {


    public void destroy() {
    }


    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain) throws IOException, ServletException {
// 处理请求乱码
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletRequest myRequest = (HttpServletRequest) new MyRequest(httpServletRequest);


// 处理响应乱码
        response.setContentType("text/html;charset=utf-8");


        chain.doFilter(myRequest, response);
    }

    public void init(FilterConfig filterConfig) throws ServletException {
    }


}


// 自定义request对象
class MyRequest extends HttpServletRequestWrapper {


    private HttpServletRequest request;


    private boolean hasEncode;


    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();
    }


    @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
    }


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


}

web.xml配置

<!--配置过滤器-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.he.filter.EncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>```