Limit数据库端分页

技术2022-05-11 86

package com.sinovs.saler.webapp.action;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;

import org.apache.struts.action.DispatchAction;

import org.apache.struts.action.ActionForward;

import org.apache.struts.action.ActionMapping;

import org.apache.struts.action.ActionMessage;

import org.apache.struts.action.ActionMessages;

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.sinovs.saler.model.Saler;

import com.sinovs.saler.service.SalerManager;

public final class SalerAction extends DispatchAction {

public ActionForward search(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response)

throws Exception {

//从spring中得到的bean

SalerManager mgr = (SalerManager) getBean( "salerManager" );

/**

* controller首先需要创建一个Limit

String tableId = "ec";

Context context = new HttpServletRequestContext(request);

LimitFactory limitFactory = new TableLimitFactory(context, tableId);

Limit limit = new TableLimit(limitFactory);

/**

* 得到系统默认的页面显示大小

Preferences preferences = new TableProperties();

preferences.init(null, TableModelUtils.getPreferencesLocation(context));

String crdStr = tableId + "_" + TableConstants.CURRENT_ROWS_DISPLAYED;

/**

* 注意：此处取值时，如果后台配置文件里有配置，就从里面取，反之取15

int defaultRowsDisplayed = Integer.parseInt(preferences

.getPreference(PreferencesConstants.TABLE_ROWS_DISPLAYED));

if (request.getParameter(crdStr) != null) {

defaultRowsDisplayed = Integer.parseInt(request

.getParameter(crdStr));

}

/**

* limit需要得到所有的行来得到行的信息

int totalRows = mgr.getTotalSalers(limit);

limit.setRowAttributes(totalRows, defaultRowsDisplayed);

/**

* 需要从services得到Collection数据

List list = mgr.getSalers(limit);

/**

* 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("list", list);

request.setAttribute("totalRows", new Integer(totalRows));

return mapping.findForward("list");

}

SalerManagerImpl

/**

* controller需要到第一条信息就是总行数。

private final static String salersQuery = "FROM Saler ";

private final static String totalSalersQuery = "SELECT count(*) FROM Saler ";

public int getTotalSalers(Limit limit) {

String totalQuery = totalSalersQuery;

String modTotalQuery = filterQuery(limit.getFilterSet(), totalQuery);

int totalRows = dao.getTotalSalers(modTotalQuery);

return totalRows;

}

public List getSalers(Limit limit) {

String query = salersQuery;

String modSalersQuery = filterQuery(limit.getFilterSet(), query);

modSalersQuery = sortQuery(limit.getSort(), modSalersQuery);

return dao.getSalers(modSalersQuery, limit);

}

private String filterQuery(FilterSet filterSet, String query) {

if (!filterSet.isFiltered() || filterSet.isCleared()) {

return query;

}

Filter filters[] = filterSet.getFilters();

for (int i = 0; i < filters.length; i++) {

Filter filter = filters[i];

String property = filter.getProperty();

String value = filter.getValue();

query = filterQuery(query, property, value);

}

return query;

}

public String filterQuery(String query, String property, String value) {

StringBuffer result = new StringBuffer(query);

if (query.indexOf("WHERE") == -1) {

result.append(" WHERE 1 = 1 "); // stub WHERE clause so can just

// append AND clause

}

result.append(" AND " + property + " like '%" + value + "%'");

return result.toString();

}

private String sortQuery(Sort sort, String query) {

if (!sort.isSorted()) {

return query;

}

String property = sort.getProperty();

String sortOrder = sort.getSortOrder();

return sortQuery(query, property, sortOrder);

}

public String sortQuery(String query, String property, String sortOrder) {

StringBuffer result = new StringBuffer(query + " ORDER BY ");

result.append(property + " " + sortOrder);

return result.toString();

}

SalerDaoHibernate

/**

* 得到数据总行数

public int getTotalSalers(String query) {

int totalRows = 0;

List list = getHibernateTemplate().find(query);

if (list.size() > 0) {

totalRows = ((Integer) list.get(0)).intValue();

}

return totalRows;

}

/**

* 根据HQL语句的到纪录列表

public List getSalers(String query, Limit limit) {

Session session = this.getSession();

Query q = session.createQuery(query);

q.setFirstResult((limit.getPage() - 1)

* limit.getCurrentRowsDisplayed());

q.setMaxResults(limit.getCurrentRowsDisplayed());

return q.list();

}

页面

<ec:table

items="salerList"

var="saler"

action="${pageContext.request.contextPath}/saler.do?method=search"

imagePath="${pageContext.request.contextPath}/images/table/*.gif"

title="saler.list.title"

width="80%"

retrieveRowsCallback="org.extremecomponents.table.callback.LimitCallback" filterRowsCallback="org.extremecomponents.table.callback.LimitCallback" sortRowsCallback="org.extremecomponents.table.callback.LimitCallback"

rowsDisplayed="16"

<ec:exportXls fileName="presidents.xls" tooltip="Export Excel"/>

<ec:row highlightRow="true">

<ec:column property="rowcount" cell="rowCount" sortable="false" filterable="false" title="ID" width="60"/>

<ec:column property="salerName" title="saler.salername"/>

<ec:column property="salerPhone" title="saler.salerphone"/>

<ec:column property="id" title="saler.button.mod" filterable="false" viewsAllowed="html" sortable="false">

</ec:column>

<ec:column property="id" title="saler.button.delete" filterable="false" sortable="false" viewsAllowed="html">

</ec:column>

</ec:row>

</ec:table>

专利

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