错误描述:

org.directwebremoting.dwrp.BaseDwrpHandler - A request has been denied as a potential CSRF attack.
org.directwebremoting.dwrp.BaseCallHandler - Exception while processing batch
java.lang.SecurityException: CSRF Security Error

  at org.directwebremoting.dwrp.BaseDwrpHandler.checkNotCsrfAttack(BaseDwrpHandler.java:85)
  at org.directwebremoting.dwrp.BaseCallHandler.handle(BaseCallHandler.java:76)
  at org.directwebremoting.servlet.UrlProcessor.handle(UrlProcessor.java:120)
  at org.directwebremoting.servlet.DwrServlet.doPost(DwrServlet.java:141)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:99)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
  at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
  at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process  (Http11Protocol.java:581)
  at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
  at java.lang.Thread.run(Thread.java:619)

解决办法:

修改 web.xml 中 DWR 配置信息

原:

<servlet> 
      <servlet-name>dwr-invoker</servlet-name> 
     <servlet-class>org.directwebremoting.spring.DwrSpringServlet</servlet-class> 
     <init-param>
      <param-name>debug</param-name>
      <param-value>true</param-value>
  </init-param>
</servlet>

加入跨域调用配置信息(红色部分)，修改为:

<servlet> 
      <servlet-name>dwr-invoker</servlet-name> 
      <servlet-class>org.directwebremoting.spring.DwrSpringServlet</servlet-class> 
      <init-param>
             <param-name>debug</param-name>
             <param-value>true</param-value>
      </init-param>
      <init-param>
             <param-name>crossDomainSessionSecurity</param-name>
             <param-value>false</param-value>
      </init-param>
      <init-param>
            <param-name>allowScriptTagRemoting</param-name>
            <param-value>true</param-value>
      </init-param>
</servlet>

近期在做的S2SH项目，因为多处用到分页，BOSS要求小弟将其抽象出来。小弟不才，实际参与开发的经验也就1年。
于是花了点时间将其做成自定义标签供所有需要分页的业务调用。小结一下，供新手参考

自定义标签使用如下：
JSP页面引入：
<%@ taglib uri="/htdz-tag" prefix="htdz-tag"%>
在需要摆放翻页的相关按钮处使用：
<htdz-tag:PagerTag pagesize="${pagesize}" rowcount="${rowcount}" currpagenum="${currpagenum}" action="${action}"/>

以下介绍如何自定义标签：

1.首先是针对自定义标签的描述：
创建WEB-INF/tags/htdz-tag.tld标签描述文件：
<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
 version="2.0">
    <description>htdz tag</description>
    <display-name>htdz tag</display-name>
    <tlib-version>1.0</tlib-version>
    <short-name>htdz-tag</short-name>
    <uri>/htdz-tag</uri>
 
    <tag>
          <!--分页控件使用说明：
          1.最全参数用法：<htdz-tag:PagerTag pagesize="${pagesize}" rowcount="${rowcount}" currpagenum="${currpagenum}" action="${action}" className="button_small"/>
          1.最简参数用法：<htdz-tag:PagerTag pagesize="${pagesize}" rowcount="${rowcount}" currpagenum="${currpagenum}" action="${action}"/>
          参数说明：
          1. pagesize为每页记录数(必写)
          2. rowcount为总记录数(必写)
          3. currpagenum为当前页数(必写)
          4. className为分页按钮样式，如果不写，则为默认样式
          5. action为URL请求路径(必写)
          -->
          <description>分页控件</description>
          <!--JSP里使用时的标签名-->
          <name>PagerTag</name>
          <!--用以将自定义标签解析成控件的Java类-->
          <tag-class>com.htdz.util.tag.PagerTag</tag-class>
          <body-content>JSP</body-content>
          <!--每个attribute代表标签的一个属性-->
          <attribute>
               <description>pagesize:每页条数</description>
               <!--属性名-->
               <name>pagesize</name>
               <!--是否必填属性-->
               <required>true</required>
               <!--此属性值是否接受EL,<%= 之类的形式-->
               <rtexprvalue>true</rtexprvalue>
         </attribute>
         <attribute>
             <description>rowcount:总记录数</description>
             <name>rowcount</name>
             <required>true</required>
             <rtexprvalue>true</rtexprvalue>
         </attribute>
         <attribute>
             <description>currpagenum:当前页数</description>
             <name>currpagenum</name>
             <required>true</required>
             <rtexprvalue>true</rtexprvalue>
         </attribute>
         <attribute>
             <description>action:URL请求路径</description>
             <name>action</name>
             <required>true</required>
             <rtexprvalue>true</rtexprvalue>
         </attribute>
         <attribute>
             <description>className:用于客户端确定分页按钮的样式</description>
             <name>className</name>
             <required>false</required>
         </attribute>
     </tag>

</taglib>

2.创建用于将标签解析为页面翻页控件的类
PagerTag.java

public class PagerTag extends TagSupport {

    public static final int USER_PAGESIZE = 5;// 礼品搜索--每页记录数
    private static final String DEFAULT_BUTTON_CLASS= "button_small"; //翻页按钮默认样式
    private static final String DISABLE_BUTTON_CLASS= "button_small_disable"; //失效按钮默认样式
 
    private int pagesize;
    private int rowcount;
    private int currpagenum;
    private String action;
    private String className;

    public PagerTag() {

    }

    public void setPagesize(int pagesize) {
        this.pagesize = pagesize;
    }
    public void setRowcount(int rowcount) {
        this.rowcount = rowcount;
    }
   public void setCurrpagenum(int currpagenum) {
        this.currpagenum = currpagenum;
    }
    public void setClassName(String className) {
        this.className = className;
    }
    public void setAction(String action) {
        this.action = action;
    }

    public int doStartTag() throws JspException {
 
        if (new Integer(pagesize) == null) {
            throw new JspException("PagerTag标签中缺乏pagesize属性！");
        }else if(pagesize==0){
            throw new JspException("PagerTag标签中的pagesize属性无值！");
        }
        if (new Integer(rowcount) == null) {
            throw new JspException("PagerTag标签中缺乏rowcount属性！");
        }
        if (new Integer(currpagenum) == null) {
            throw new JspException("PagerTag标签中缺乏currpagenum属性！");
        }
        if (action == null) {
            throw new JspException("PagerTag标签中缺乏action属性！");
        }else if(action.length()==0){
            throw new JspException("PagerTag标签中的action属性无值！");
        }

        //如果页面标签中没写className属性，则让翻页按钮应用默认的按钮样式
        if(className==null||className.length()==0){
            className = DEFAULT_BUTTON_CLASS;
        }
        //获取总页数
        int totalpagesize = getTotalpagesize(rowcount);

        //用以标志是否能上翻
        boolean noUp = false;
        //用以标志是否能下翻
        boolean noDown = false;

        //声明应用于'首页'，'上一页'按钮的样式(因为此俩按钮要么同时失效，要么同时可用)
        String buttonClass1 = className;
        //声明应用于'下一页'，'尾页'按钮的样式(同上)
        String buttonClass2 = className;
 
        //如果无记录，则设置总页数与当前页数都为1
        if(rowcount==0){
            currpagenum = 1;
            totalpagesize = 1;
        }
 
        //如果当前页是第一页
        if(currpagenum==1){
            noUp = true;
            //设置'首页'，'上一页'按钮失效样式
            buttonClass1 = DISABLE_BUTTON_CLASS;
        }
        //如果当前页是最大页
        if(currpagenum==totalpagesize){
            noDown = true;
            //设置'下一页'，'尾页'按钮失效样式
            buttonClass2 = DISABLE_BUTTON_CLASS;
        }
 

        try {
            StringBuffer html = new StringBuffer();
  
            html.append(currpagenum+"/"+totalpagesize+"页");

            html.append("<input class="+buttonClass1+" type=\"button\" value=\"首页\" onclick=\"turnPage('first','"+currpagenum+"','"+totalpagesize+"','"+action+"')\" ");
            if(noUp){
                html.append("disabled=\"true\"");
            }
            html.append("/>");

            html.append("<input class="+buttonClass1+" type=\"button\" value=\"上一页\" onclick=\"turnPage('up','"+currpagenum+"','"+totalpagesize+"','"+action+"')\" ");
            if(noUp){
                html.append("disabled=\"true\"");
            }
            html.append("/>");
  
            html.append("<input class="+buttonClass2+" type=\"button\" value=\"下一页\" onclick=\"turnPage('down','"+currpagenum+"','"+totalpagesize+"','"+action+"')\"");
            if(noDown){
                html.append("disabled=\"true\"");
            }
            html.append("/>");

            html.append("<input class="+buttonClass2+" type=\"button\" value=\"尾页\" onclick=\"turnPage('last','"+currpagenum+"','"+totalpagesize+"','"+action+"')\" ");
            if(noDown){
                html.append("disabled=\"true\"");
            }
            html.append("/>");

            html.append(currpagenum+"/"+totalpagesize+"页&nbsp;&nbsp;");

            html.append("<input type=\"text\" maxlength=\"3\" id=\"text\" size=\"3\" onkeypress=\"return checkInput(event);\" />页");
            html.append("<input class="+className+" type=\"button\" value=\"GO\" onclick=\"turnPage('to','"+currpagenum+"','"+totalpagesize+"','"+action+"')\" />");
            pageContext.getOut().println(html.toString());
        } catch (Exception e) {
            throw new JspException(e.getMessage());
        }
         return this.SKIP_BODY;
    }

     /**
      * 根据总记录数得到总页数
      *
      * @param rowcount
      *            总记录数
      * @return 总页数
      */
    public int getTotalpagesize(int rowcount) {
        int totalpagesize = 0;
 
        if (rowcount % pagesize == 0) {
            totalpagesize = rowcount / pagesize;
        } else {
            totalpagesize = rowcount / pagesize + 1;
        }
        return totalpagesize;
    }
}

到此为止，自定义标签书已完成。
可应用于项目各处，
只要页面上遵循标签描述规则，后台该给标签属性传值的时候记得传就行了。
以下用一个简单的例子来说明一下，红色字体显示的部分别忘记写就行了。

UserAction.java:
public class UserAction extends ActionSupport {

    private UserService userService;
    private List<User> users;

    public String findUser(){
        String str = null;
        HttpServletRequest request = ServletActionContext.getRequest();
        Map sessionMap = ActionContext.getContext().getSession();
 
        String currpagenum= "1";
        try {
            String pagenum = request.getParameter("pagenum ");
            if(pagenum != null && pagenum .length()!=0){
                currpagenum= pagenum ;
            }
        } catch (Exception e) {

        }
 
        //查询用户记录
        users= userService.findUser(pageNum);
        if(users.size!=0){
            request.setAttribute("users", users);

            int rowcount = userService.getCount();

            request.setAttribute("rowcount ",rowcount );
            request.setAttribute("currpagenum",currpagenum);

            str = "success";//成功视图
        }else{
            message = "无记录!"               
            str = "failure";//失败视图
        }
  
        request.setAttribute("pagesize", PagerTag.USER_PAGESIZE);
        request.setAttribute("action", "findUser.action);

        //返回视图
        return str;
    }

    public UserService getUserService() {
        return userService;
    }
    public void setUserService(UserService userService) {
        this.userService = userService;
    }
   
    public List<User> getUsers(){
        return users;
    }
    public void setUsers(List<User> users){
        this.users = users;   
    }

}

 
UserService.java:

public class UserService {

    private UserDao userDao;

    public List<User> findUser(String pageNum){
        List<User> userList = userDao.findUser(pageNum);
        return userList;
    }

    public int getCount(){
        int count = userDao.getCount();
        return count;
    }

    public UserDao getUserDao() {
        return userDao;
    }
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
}

UserDao.java:

public class UserDao extends HibernateDaoSupport {

    /**
     * 查询用户
     * @return User对象集合
     */
    public List<User> findUser(String pagenum) {
        List<User> users = null;
        Session session = null;
        try {
            int myPagenum= Integer.parseInt(pagenum);
            String hql = "from User";
            session = this.getSession();
            Query query = session.createQuery(hql);
            query.setFirstResult(Pager.USER_PAGESIZE * (myPagenum - 1));
            query.setMaxResults(Pager.USER_PAGESIZE);
            users = query.list();
            session.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
        if (session != null) {
            session.close();
        }
    }
    return users;
}

    /**
     * 获取用户总记录数
     * @return 用户总记录数
     */
    public int getCount(){
        String hql ="select count(id) from User";
        Session session = null;
        int count =0;
        try {
            session = this.getSession();
            Query query = session.createQuery(hql);
            List list = query.list();
            session.flush();
            count = Integer.parseInt(list.get(0).toString());
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
        session.close();
        }
        return count;
    }

}