一、HandlerInterceptor 用法

第一步：註冊攔截器

<!-- 註冊攔截器 -->
    <mvc:interceptors>
        <bean class="com.project.base.interceptor.ControlInterceptor" />
    </mvc:interceptors>

第二步：繼承HandlerInterceptor ，實現攔截器

package com.iflashbuy.limanman;

import java.util.Iterator;
import java.util.Map;

import
 
 javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class ControlInterceptor implements
 
 HandlerInterceptor{
    private Logger logger  = LoggerFactory.getLogger(getClass());
    /**
     * 執行完控制器後呼叫，即離開時
     */
    @Override
    public void afterCompletion(HttpServletRequest request,
            HttpServletResponse response, Object arg2, Exception arg3)
                    throws Exception {
    }
    @Override
 

    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
            throws Exception {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse arg1, Object arg2) throws Exception {
        int i = 1;
        try {
            @SuppressWarnings("unchecked")
            Map<String, Object> parmMap = request.getParameterMap();
            Iterator<String> iter = parmMap.keySet().iterator();
            while (iter.hasNext()) {
                Object key = iter.next();
                Object value = parmMap.get(key);
                logger.info("第" + i + "個param---->{}-{}", key, value);
                i = i + 1;
            }
        } catch (Exception e) {
            i = 1;
        }
        i = 1;
        return true;

    }

}

二、後臺列印資訊效果

三、拓展使用攔截器實現http基本認證

/**
     * 執行完控制器後呼叫，即離開時
     */
    @Override
    public void afterCompletion(HttpServletRequest request,
            HttpServletResponse response, Object arg2, Exception arg3)
            throws Exception {

        logger.info("className--->" + arg2);
        logger.info("request--->" + request);
    }

    @Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object arg2, ModelAndView arg3)
            throws Exception {

    }

    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object arg2) throws Exception {
        String sessionAuth = (String) request.getSession().getAttribute("auth");
        if (sessionAuth != null) {
            System.out.println("this is next step");
            nextStep(request, response);

        } else {

            if (!checkHeaderAuth(request, response)) {
                response.setStatus(401);
                response.setHeader("Cache-Control", "no-store");
                response.setDateHeader("Expires", 0);
                response.setHeader("WWW-authenticate", "Basic Realm=\"請輸入管理員賬號密碼\"");
                return false;
            }

        }
        return true;
    }

    private boolean checkHeaderAuth(HttpServletRequest request,
            HttpServletResponse response) throws IOException {

        String auth = request.getHeader("Authorization");
        System.out.println("auth encoded in base64 is " + getFromBASE64(auth));

        if ((auth != null) && (auth.length() > 6)) {
            auth = auth.substring(6, auth.length());

            String decodedAuth = getFromBASE64(auth);
            System.out.println("auth decoded from base64 is " + decodedAuth);

            request.getSession().setAttribute("auth", decodedAuth);
            return true;
        } else {
            return false;
        }

    }

    private String getFromBASE64(String s) {
        if (s == null)
            return null;
        try {
            byte[] encodeBase64 = Base64.encodeBase64(s.getBytes("UTF-8"));
            return new String(encodeBase64);
        } catch (UnsupportedEncodingException e) {
            return null;
        }


    }

    public void nextStep(HttpServletRequest request,
            HttpServletResponse response) throws IOException {
        System.out.println("you can go to the controller");
    }