struts2整合extremeTable

1.Limit
默认的情况下eXtremeTable取得所有的结果集然后处理Beans集合，这样的好处是 你可以随意进行排序、过滤和分页操作。
你只需要组装Beans集合并让eXtremeTable知道如何 然而在查询结果较大，可以考虑使用数据库端分页的方案。此时，eXtremeTable
会使用Limit对象向Action/Controller传递PageNo,PageSize,OrderBy等分页信息。而服务端将向EC返回总记录数和当前页的内容。

2.创建Limit

首先你需要通过LimitFactory得到一个Limit实例：

Java代码
Context context = new HttpServletRequestContext(request);
LimitFactory limitFactory = new TableLimitFactory(context);
Limit limit = new TableLimit(limitFactory);
Limit对象定义了limit结果集的所有方法。
TableLimitFactory具有另外一个构造函数，如果JSP页面使用了两个（以上）eXtremeTable的话你可以利用tableId分别传输totalRows,如果默认tableId将为所有ec,。

Context context = new HttpServletRequestContext(request);
LimitFactory limitFactory = new TableLimitFactory(context, tableId);
Limit limit = new TableLimit(limitFactory);
设置行属性：

limit.setRowAttributes(totalRows, DEFAULT_ROWS_DISPLAYED);

3. 前台jsp页面中ec标莶写法：
Java代码
<ec:table
items="userlist"
var="u"
action="/pageAction.do"
title="后台用户管理——管理用户"
retrieveRowsCallback="limit"
width="80%"
rowsDisplayed="3"
form=""
>
<ec:row>
...
...
</ec:row>
</ec:table>
使用callback需要做的唯一事情是传输集合到request，同时传输totalRows属性。 totalRows表示总行数，

Java代码
request.setAttribute("userlist", userlist);
request.setAttribute("totalRows", new Integer(总记录数));

4.实例：

PageAction中的部分代码：

Java代码
package tutorial.extremeTable.action;import java.util.ArrayList;import java.util.List;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.struts2.interceptor.ServletRequestAware;import org.apache.struts2.interceptor.ServletResponseAware;import org.apache.struts2.interceptor.SessionAware;import org.extremecomponents.table.context.Context;import org.extremecomponents.table.context.HttpServletRequestContext;import org.extremecomponents.table.core.Preferences;import org.extremecomponents.table.core.PreferencesConstants;import org.extremecomponents.table.core.TableConstants;import org.extremecomponents.table.core.TableModelUtils;import org.extremecomponents.table.core.TableProperties;import org.extremecomponents.table.limit.Limit;import org.extremecomponents.table.limit.LimitFactory;import org.extremecomponents.table.limit.TableLimit;import org.extremecomponents.table.limit.TableLimitFactory;import com.opensymphony.xwork2.ActionSupport;public class ExtremeLimitAction extends ActionSupport implements SessionAware, ServletRequestAware, ServletResponseAware { private String message; private Map att; private HttpServletRequest request; private HttpServletResponse response; public String getMessage() { return message; } public void setSession(Map att) { this.att = att; } public void setServletRequest(HttpServletRequest request) { this.request = request; } public void setServletResponse(HttpServletResponse response) { this.response = response; } public String execute() { UserDAO userDAO = (UserDAO) getBean("userDAO"); Limit limit = ExtremeTablePage.getLimit(request,defaultPageSize); PageBean page = new PageBean(); page.setPageSize(limit.getCurrentRowsDisplayed()); //ec通过limit对象传递pageSize给PageBean page.setPage(limit.getPage());//ec通过limit对象传递pageNo给PageBean List list = userDAO.findAllUser(page); /** * * 将Collections和totalRow这些信息传送回JSP以便eXtremeTable知道如何显示这些信息 * */ request.setAttribute("userlist", list); request.setAttribute("totalRows", new Integer(page.getCount())); return SUCCESS; }}
Limit对象的实例化在ExtremeTablePage中

Java代码
static public Limit getLimit(HttpServletRequest request,int defaultPageSize) {
Context context = new HttpServletRequestContext(request);
LimitFactory limitFactory = new TableLimitFactory(context);
TableLimit limit = new TableLimit(limitFactory);
limit.setRowAttributes(Integer.MAX_VALUE, defaultPageSize);
return limit;
}

PageBean类部分代码:

Java代码
public class PageBean {
private int count = 0; // 记录总数
private int pageSize = 10; // 每页显示记录数
private int pageCount = 0; // 总页数
private int page = 1; // 当前页数
.
.
.
public int getCount() {
return count;
}
public void setCount(int count) {
if (pageSize != 0) {
pageCount = count / pageSize;
if (count % pageSize != 0) {
pageCount++;
}
}
this.count = count;
}

public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getPageCount() {
return pageCount;
}
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
.
.
.
}dao层使用PageBean对象进行查询。