【SpringMVC】(六)乱码问题

乱码问题

1.测试环境

index.jsp：编写一个表单

<form action="/e/t1" method="post" >
    <input type="text" name="name">
    <input type="submit">
</form>

Controller

@Controller
public class EncodingController {

    @PostMapping("/e/t1")
    public String test1(String name, Model model) {
        model.addAttribute("msg", name);
        return "test";
    }

}

test.jsp

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

2.以前的办法：自定义简单过滤器

EncodingFilter.java

@WebFilter("/*") //注意servlet导入依赖版本一定是3.0及以上的
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() {

    }
}

3.解决办法一：SpringMVC提供的过滤器

web.xml中配置

	<!--SpringMVC提供的过滤器-->
    <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>

url-pattern为/和/*的区别：
1./会匹配请求，不会匹配*.jsp等后缀型url
2./*会所有请求和后缀型的url

4.解决办法二：修改tomcat配置文件，设置编码

D:\Tomcat\apache-tomcat-8.5.39\apache-tomcat-8.5.39\conf\server.xml

<Connector URIEncoding = "utf-8" port = "8080" protocol = "HTTP/1.1" connectionTimeout = "20000" redirectPort = "8443" />

5.解决办法三：终极自定义过滤器

GenericEncodingFilter.java

public class GenericEncodingFilter implements Filter {

    public void init(FilterConfig filterConfig) throws ServletException {

    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //处理response的字符编码
        HttpServletResponse myResponse = (HttpServletResponse) servletResponse;
        myResponse.setContentType("text/html;charset=UTF-8");

        //转型为与协议相关对象
        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
        //对request包装增强
        HttpServletRequest myRequest = new MyRequest(httpServletRequest);

        filterChain.doFilter(myRequest, servletResponse);

    }

    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);
        this.request = request;
    }

    //对需要增强方法 进行覆盖
    public Map getParameterMap() {
        //先获得请求方法
        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) {
                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
    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
    public String[] getParameterValues(String name) {
        Map<String, String[]> parameterMap = getParameterMap();
        String[] values = parameterMap.get(name);
        return values;
    }

}

web.xml

	<!--配置SpringMVC的乱码过滤-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>com.musecho.filter.GenericEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

posted @ 2021-02-12 16:41 musecho 阅读(59) 评论(0) 收藏举报

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musecho

【SpringMVC】(六)乱码问题

乱码问题

1.测试环境

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