出现乱码一般都是post居多

解决post get 请求乱码

在 Tomcat 为 URIEncoding="utf-8" 前提下，为啥post 字符串的格式还是 ISO-8859-1 ?

方式一：SpringMVC过滤器

据说：极端情况下.这个过滤器对get的支持不好(鄙人没发现，这个就挺好)

    <filter>
        <filter-name>CharacterEncodingFilter</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>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

springmvc.png

方式二：更改Tomcat 编码配置 URIEncoding="utf-8"

我咋觉着没啥用呢(实测没啥用，改了兼容性好。没有问题不改也行)
配置文件路径：apache-tomcat-8.5.72/conf/server.xml

<Connector port="8080" protocol="HTTP/1.1" URIEncoding="utf-8"
               connectionTimeout="20000"
               redirectPort="8443" relaxedPathChars="|{}[],%" relaxedQueryChars="|{}[],%" />

tomcat-config.png

方式三：抄大神作业

springmvc 不好用就试试这个。

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;

public class GenericEncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @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);
    }


}

//自定义request对象，HttpServletRequest的包装类
class MyRequest extends HttpServletRequestWrapper{

    private HttpServletRequest request;

    // 是否编码
    private boolean hasEncode;

    // 定义一个可以传入 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<String, String[]> 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++) {

                            String targetStr = values[I];
                            String encode = "ISO-8859-1";
                            try {
                                //  "ISO-8859-1" 转为 utf-8
                                if (targetStr.equals(new String(targetStr.getBytes(encode), encode))) {
                                    try {
                                        // 处理get乱码
                                        values[i] = new String(values[i].getBytes(encode), "utf-8");
                                    } catch (UnsupportedEncodingException e) {
                                        e.printStackTrace();
                                    }
                                }
                            } catch (final 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;
    }
}

copy.png

处理请求返回json字符串的中文乱码问题

方式一、通过spring 配置一次性解决乱码

<mvc:annotation-driven>
      <mvc:message-converters register-defaults="true">
         <!-- StringHttpMessageConverter编码为UTF-8，防止乱码 -->
         <bean class="org.springframework.http.converter.StringHttpMessageConverter">
            <constructor-arg value="UTF-8" />
         </bean>
         <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="objectMapper">
               <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                  <property name="failOnEmptyBeans" value="false"/>
               </bean>
            </property>
         </bean>
      </mvc:message-converters>
   </mvc:annotation-driven>

方式二、produces:指定响应体返回类型和编码

@RequestMapping(value = "/json1",produces = "application/json;charset=utf-8")

json1.png