ext grid 数据库分页实现
看了robbin 关于hibernate 分页的老帖(http://www.iteye.com/topic/261)，把ext grid 的数据库分页整了下，完全满足需要，呵呵，贴出代码与大家共同学习下：
DAO代码：
服务层：
action 代码：
开始无数据时怎么也不能显示PagingToolbar 的emptyMsg，后来发现空数据时组织格式错误，忘记去掉 [{"rows":[],"results":"0"}]这部分的“[]”，这个小问题折磨了俺好久，呵呵，要细心啊～！
DAO代码：
/**
* 获取符合查询条件的记录总数
* @param detachedCriteria hibernate Criteria 查询对象，由service组装
* @return
*/
public Long getRecordCount(final DetachedCriteria detachedCriteria) {
return (Long) getHibernateTemplate().execute(new HibernateCallback() {
public Object doInHibernate(Session session)
throws HibernateException {
Criteria criteria = detachedCriteria
.getExecutableCriteria(session);
long count = Long.parseLong((criteria.setProjection(Projections
.rowCount()).uniqueResult()).toString());
criteria.setProjection(null);
return Long.valueOf("" + count);
}
}, true);
}
/**
* 获取符合条件的查询记录
* @param detachedCriteria
* @param startResult
* @param limitResult
* @return
*/
public List listByConditions(final DetachedCriteria detachedCriteria,
final int startResult, final int limitResult) {
return (List) getHibernateTemplate().execute(new HibernateCallback() {
public Object doInHibernate(Session session)
throws HibernateException {
Criteria criteria = detachedCriteria
.getExecutableCriteria(session);
criteria.setFirstResult(startResult);
criteria.setMaxResults(limitResult);
return criteria.list();
}
}, true);
}
服务层：
/**
* 获取所有日志列表
* @param startResult 查询记录起点
* @param limitResult 简要列表每页最大记录数
* @param sortRecord 简要列表排序字段名
* @param dirRecord 简要列表排序类型 DESE/ASC
* @return
*/
public JSONArray getAllLogs(String startResult,String limitResult,
String sortRecord,String dirRecord) {
try {
DetachedCriteria detachedCriteria = DetachedCriteria.forClass(TDeasLog.class);
if(dirRecord.equals("ASC"))
detachedCriteria.addOrder(Order.asc(sortRecord));
else
detachedCriteria.addOrder(Order.desc(sortRecord));
Long count = logDAO.getRecordCount(detachedCriteria);//获取符合条件的记录总数
List list = logDAO.listByConditions(detachedCriteria, Integer.parseInt(startResult),
Integer.parseInt(limitResult));//获取符合条件记录
if(list.size()>0){
List jsonlist = new ArrayList();
Iterator it = list.iterator();
while (it.hasNext()){
Log log = (Log )it.next();
Map map = new HashMap();
map.put("taskId", log .getTaskId());
map.put("rwfssj", log .getRwfssj());
map.put("rwjssj", log .getRwjssj());
....
jsonlist.add(map);
}
Map m = new HashMap();
m.put("results", count.toString());
m.put("rows", jsonlist);
JSONArray jsonArray = JSONArray.fromObject(m);
return jsonArray;
}else
return null;
} catch (Exception e) {
e.printStackTrace();
return null;
}
action 代码：
public ActionForward getAllLogs(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
String startResult = request.getParameter("start");
String limitResult = request.getParameter("limit");
String sortRecord = request.getParameter("sort");
String dirRecord = request.getParameter("dir");
JSONArray jsonArray = this.getLogService().getAllLogs(startResult,limitResult,sortRecord,dirRecord);
if(jsonArray != null){
String jsonstr = jsonArray.toString();
//去除JSON对象前的[]
String json = jsonstr.substring(1, jsonstr.length()-1);
response.setContentType("text/json; charset=utf-8");
try {
response.getWriter().print(json);
} catch (IOException e) {
log.error("获取日志实例列表失败，异常："+e.getMessage());
}
}else{//返回空数据，格式：{"rows":[],"results":"0"}
List list = new ArrayList();
Map map1 = new HashMap();
list.add(map1);
Map m = new HashMap();
m.put("results", "0");
m.put("rows", list);
JSONArray json = JSONArray.fromObject(m);
String jsonString = json.toString();
String jsonstr =jsonString.substring(1, jsonString.length()-1);
response.setContentType("text/json; charset=utf-8");
try {
response.getWriter().print(jsonstr);
} catch (IOException e) {
log.error("获取日志实例列表失败，异常："+e.getMessage());
}
}
return null;
}
开始无数据时怎么也不能显示PagingToolbar 的emptyMsg，后来发现空数据时组织格式错误，忘记去掉 [{"rows":[],"results":"0"}]这部分的“[]”，这个小问题折磨了俺好久，呵呵，要细心啊～！
var datastore = new Ext.data.Store({
proxy: new Ext.data.HttpProxy({
url: 'logManage.do?method=getAllLogs'
}),
reader: new Ext.data.JsonReader({
root : 'rows',
totalProperty : 'results',
id: 'taskID'
}, [
{name: 'taskId'},
{name: 'rwfssj'},
{name: 'rwjssj'},
....
]),
remoteSort: true
});
datastore.setDefaultSort('taskId','ASC');
datastore.load({params:{start:0, limit:10}});
var sm = new Ext.grid.CheckboxSelectionModel();
var colModel = new Ext.grid.ColumnModel([
new Ext.grid.RowNumberer(),
{ header:'任务ID', width:100, sortable:true, locked:true, dataIndex:'taskId'},
{ header:'任务类型', width:100, sortable:true, locked:false, dataIndex:'rwlb'},
{ header:'任务状态', width:100, sortable:true, locked:false, dataIndex:'rwzt'},
......
]);
var LogGrid = new Ext.grid.GridPanel({
ds : datastore,
cm : colModel,
sm : sm,
id : 'LogGrid',
title : '日志列表',
autoHeight : true,
width : '100%',
loadMask : true,
buttons : [{
text : '查询',
tooltip : '日志查询',
handler : logSearch
},{
text : '关闭',
tooltip : '关闭窗口',
handler : closeForm
}],
buttonAlign : 'right',
bbar : new Ext.PagingToolbar({
id : 'pagingbar',
pageSize : 10,
store : datastore,
displayInfo : true
})
});