實現機制是使用token,簡單說下:
(a)進入下單頁,會生成一個token,同時存在兩個地方:session(或redis也可以)和頁面
(b)提交時,服務器接收到頁面的token後,會和session中的token比較,相同則允許提交,同時刪除session中的token;
(c)如果重複提交,則session中已經沒有token(已被步驟b刪除),那麼校驗不通過,則不會真正提交.
攔截器代碼:下載
- package com.chanjet.gov.filter;
- import org.apache.log4j.Logger;
- import org.springframework.web.method.HandlerMethod;
- import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import java.lang.reflect.Method;
- import java.util.UUID;
- /**
- * Created by 黃威 on 9/20/16.<br >
- * 防止下單頁重複提交
- */
- public class RepeatTokenInterceptor extends HandlerInterceptorAdapter {
- private static Logger log = Logger.getLogger(RepeatTokenInterceptor.class);
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
- if (handler instanceof HandlerMethod) {
- HandlerMethod handlerMethod = (HandlerMethod) handler;
- Method method = handlerMethod.getMethod();
- RepeatSubmitToken annotation = method.getAnnotation(RepeatSubmitToken.class);
- if (annotation != null) {
- boolean needSaveSession = annotation.save();
- if (needSaveSession) {
- request.getSession(true).setAttribute("repeattoken", UUID.randomUUID().toString());
- }
- boolean needRemoveSession = annotation.remove();
- if (needRemoveSession) {
- if (isRepeatSubmit(request)) {
- log.warn("please don't repeat submit,url:" + request.getServletPath());
- response.sendRedirect("/warn.html?code=repeatSubmitOrder&orgId="+request.getParameter("orgId"));
- return false;
- }
- request.getSession(true).removeAttribute("repeattoken");
- }
- }
- return true;
- } else {
- return super.preHandle(request, response, handler);
- }
- }
- private boolean isRepeatSubmit(HttpServletRequest request) {
- String serverToken = (String) request.getSession(true).getAttribute("repeattoken");
- if (serverToken == null) {
- return true;
- }
- String clinetToken = request.getParameter("repeattoken");
- if (clinetToken == null) {
- return true;
- }
- if (!serverToken.equals(clinetToken)) {
- return true;
- }
- return false;
- }
- }
但是--
如果打開兩個標籤頁,則這兩個頁面分別有一個token,並且是不同的(理論上是不同的),但是session中只有一份,
其中一個提交後,就會刪除session中的token,那麼另外一個頁面提交時session中的token已爲空,那麼一定校驗不通過.
根本原因:
在同一時刻,session中只存了一份token,而頁面上可能有多個token(有n個頁籤,就會有n個不同的token).
既然找到了根本原因,那麼也就自然而然產生了解決方案.
思路:session中不能只存儲一份token,而是支持存儲多個token
具體技術方案:下載
(1)每次進入下單頁都會產生一個新的token,這個token都進入兩個數據流:
--(a)傳到頁面,key是repeattoken
前端頁面引用方式:
- <input type="hidden" name="repeattoken" value="${Session.repeattoken!}" >
--(b)存儲到session(現在是增量,不會把原來的token替換掉)
(2)存儲到session中的key應該與頁面的key區分開來,使用"tokenpool"
優化之後的過濾器:下載
- package com.chanjet.gov.filter;
- import com.chanjet.gov.util.StringUtil;
- import org.apache.log4j.Logger;
- import org.springframework.web.method.HandlerMethod;
- import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import javax.servlet.http.HttpSession;
- import java.lang.reflect.Method;
- import java.util.UUID;
- /**
- * Created by 黃威 on 9/20/16.<br >
- * 防止下單頁重複提交
- */
- public class RepeatTokenInterceptor extends HandlerInterceptorAdapter {
- /***
- * 用於前端頁面接收服務器端的token
- */
- public static final String SESSION_KEY_REPEATTOKEN="repeattoken";
- /***
- * 用於session存儲n個token
- */
- public static final String SESSION_KEY_REPEATTOKEN_POOL = "tokenpool";
- private static Logger log = Logger.getLogger(RepeatTokenInterceptor.class);
- private void addRepeatToken(HttpServletRequest request, HttpServletResponse response){
- HttpSession httpSession = request.getSession(true);
- String token = (String) httpSession.getAttribute(SESSION_KEY_REPEATTOKEN_POOL);
- System.out.println("addRepeatToken token:"+token);
- String createdToken = UUID.randomUUID().toString();
- httpSession.setAttribute(SESSION_KEY_REPEATTOKEN, createdToken);//給前端頁面用的
- if(StringUtil.isNullOrEmpty(token)){
- httpSession.setAttribute(SESSION_KEY_REPEATTOKEN_POOL, createdToken);
- }else{
- httpSession.setAttribute(SESSION_KEY_REPEATTOKEN_POOL, createdToken + "###" + token);
- }
- }
- private void removeRepeatToken(HttpServletRequest request, HttpServletResponse response){
- HttpSession httpSession = request.getSession(true);
- String token = (String) httpSession.getAttribute(SESSION_KEY_REPEATTOKEN_POOL);
- System.out.println("removeRepeatToken token:"+token);
- if(!StringUtil.isNullOrEmpty(token)){
- String clientToken = (String) request.getParameter(SESSION_KEY_REPEATTOKEN);
- System.out.println("removeRepeatToken serverToken:"+clientToken);
- if (clientToken == null) {
- return;
- }
- token = token.replace(clientToken, "").replace("######", "###");
- System.out.println("token:"+token);
- httpSession.setAttribute(SESSION_KEY_REPEATTOKEN_POOL, token);
- }
- }
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
- if (handler instanceof HandlerMethod) {
- HandlerMethod handlerMethod = (HandlerMethod) handler;
- Method method = handlerMethod.getMethod();
- RepeatSubmitToken annotation = method.getAnnotation(RepeatSubmitToken.class);
- if (annotation != null) {
- boolean needSaveSession = annotation.save();
- if (needSaveSession) {
- addRepeatToken(request,response);
- }
- boolean needRemoveSession = annotation.remove();
- if (needRemoveSession) {
- if (isRepeatSubmit(request)) {
- log.warn("please don't repeat submit,url:" + request.getServletPath());
- response.sendRedirect("/warn.html?code=repeatSubmitOrder&orgId="+request.getParameter("orgId"));
- return false;
- }
- removeRepeatToken(request,response);
- }
- }
- return true;
- } else {
- return super.preHandle(request, response, handler);
- }
- }
- private boolean isRepeatSubmit(HttpServletRequest request) {
- //從池子裏面獲取token
- String serverToken = (String) request.getSession(true).getAttribute(SESSION_KEY_REPEATTOKEN_POOL);
- if (serverToken == null||"###".equals(serverToken)) {
- return true;
- }
- String clinetToken = request.getParameter(SESSION_KEY_REPEATTOKEN);//請求要素
- if (StringUtil.isNullOrEmpty(clinetToken)) {
- return true;
- }
- System.out.println("clinetToken:"+clinetToken);
- if (!serverToken.contains(clinetToken)) {
- return true;
- }
- return false;
- }
- }
日誌:
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
removeRepeatToken token:c171f626-f218-4d19-bbb8-7aa209523c69###1b50afdf-df24-4553-89d2-701af06a431e
removeRepeatToken serverToken:1b50afdf-df24-4553-89d2-701af06a431e
token:c171f626-f218-4d19-bbb8-7aa209523c69###
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:03,379 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:03,546 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:03,751 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:03,919 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:04,129 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:04,370 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:04,476 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:04,703 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
clinetToken:1b50afdf-df24-4553-89d2-701af06a431e
09:26:04,874 WARN RepeatTokenInterceptor:70 - please don't repeat submit,url:/order/submitOrder
submit