【Spring MVC架構】亂碼問題解決

使用方法：

• 在web.xml中配置Spring MVC的亂碼過濾器

<!--在web.xml中配置Spring MVC的亂碼過濾器-->
   <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>
           

• 極端情況下，可以使用自定義過濾器

  EncodingFilter.java

  :

package filter;

/**
 * @author jitwxs
 * @date 2021年04月20日 19:41
 */
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;

/**
 * 解決get和post請求 全部亂碼的過濾器
 */
public class EncodingFilter implements Filter {

        @Override
        public void destroy() {
        }

        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
                //處理response的字元編碼
                HttpServletResponse myResponse=(HttpServletResponse) response;
                myResponse.setContentType("text/html;charset=UTF-8");

                // 轉型為與協定相關對象
                HttpServletRequest httpServletRequest = (HttpServletRequest) request;
                // 對request包裝增強
                HttpServletRequest myrequest = new MyRequest(httpServletRequest);
                chain.doFilter(myrequest, response);
        }

        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
        }

}

//自定義request對象，HttpServletRequest的包裝類
class MyRequest extends HttpServletRequestWrapper {

        private HttpServletRequest request;
        //是否編碼的标記
        private boolean hasEncode;
        //定義一個可以傳入HttpServletRequest對象的構造函數，以便對其進行裝飾
        public MyRequest(HttpServletRequest request) {
                super(request);// super必須寫
                this.request = request;
        }

        // 對需要增強方法 進行覆寫
        @Override
        public Map getParameterMap() {
                // 先獲得請求方式
                String method = request.getMethod();
                if (method.equalsIgnoreCase("post")) {
                        // post請求
                        try {
                                // 處理post亂碼
                                request.setCharacterEncoding("utf-8");
                                return request.getParameterMap();
                        } catch (UnsupportedEncodingException e) {
                                e.printStackTrace();
                        }
                } else if (method.equalsIgnoreCase("get")) {
                        // get請求
                        Map<String, String[]> parameterMap = request.getParameterMap();
                        if (!hasEncode) { // 確定get手動編碼邏輯隻運作一次
                                for (String parameterName : parameterMap.keySet()) {
                                        String[] values = parameterMap.get(parameterName);
                                        if (values != null) {
                                                for (int i = 0; i < values.length; i++) {
                                                        try {
                                                                // 處理get亂碼
                                                                values[i] = new String(values[i]
                                                                        .getBytes("ISO-8859-1"), "utf-8");
                                                        } catch (UnsupportedEncodingException e) {
                                                                e.printStackTrace();
                                                        }
                                                }
                                        }
                                }
                                hasEncode = true;
                        }
                        return parameterMap;
                }
                return super.getParameterMap();
        }

        //取一個值
        @Override
        public String getParameter(String name) {
                Map<String, String[]> parameterMap = getParameterMap();
                String[] values = parameterMap.get(name);
                if (values == null) {
                        return null;
                }
                return values[0]; // 取回參數的第一個值
        }

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

web.xml:

<filter>
        <filter-name>encoding</filter-name>
        <filter-class>filter.EncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>