Crm管理系统—分页的实现
1.jsp的实现
注：有hidden项，其作用是保存当前页pageNum
<s:hidden id="pageNum" name="pageNum"
value="1"/>
<td align="right">
<span>第<s:property value="pageBean.pageNum"/> / <s:property value="pageBean.totalPage"/>页</span>
<span>
<s:if test="pageBean.pageNum > 1">
<a href="javascript:void(0)" onclick="showPage(1)">[首页]</a>
<a href="javascript:void(0)" onclick="showPage(<s:property value="pageBean.pageNum - 1"/>)">[上一页]</a>
</s:if>
<%--动态显示页 --%>
<s:iterator begin="pageBean.start" end="pageBean.end" var="num">
<a href="javascript:void(0)" onclick="showPage(<s:property value="#num"/>)"><s:property value="#num"/></a>
</s:iterator>
<s:if test="pageBean.pageNum < pageBean.totalPage">
<a href="javascript:void(0)" onclick="showPage(<s:property value="pageBean.pageNum + 1"/>)">[下一页]</a>
<a href="javascript:void(0)" onclick="showPage(<s:property value="pageBean.totalPage"/>)">[尾页]</a>
</s:if>
</span>
</td>
<script type="text/javascript">
function showPage(num){
//1.修改隐藏域的值
document.getElementById("pageNum").value=num;
//2.提交表单
document.forms[0].submit();
}
</script>2.action的实现
public String findAll(){
//分页+条件
PageBean<CrmCourseType> pageBean = this.courseTypeService.findAll(courseType,pageNum,pageSize);
ActionContext.getContext().getValueStack().set("pageBean", pageBean);
return "findAll";
}3.service的实现
public PageBean<CrmCourseType> findAll(CrmCourseType courseType,
int pageNum, int pageSize) {
//拼凑查询条件（and...and...）
//拼凑实际参数 可以重复，顺序（Object[] params）
StringBuilder builder = new StringBuilder();
List<Object> paramList = new ArrayList<Object>();
//过滤条件
//1.课程类别 if(StringUtils.isNotBlank(courseType.getCourseName())){
builder.append(" and courseName like ? ");
paramList.add("%"+courseType.getCourseName()+"%");
}
//2.课程简介 if(StringUtils.isNotBlank(courseType.getRemark())){
builder.append(" and remark like ? ");
paramList.add("%"+courseType.getRemark()+"%");
}
//3.学时 if(StringUtils.isNotBlank(courseType.getTotalStart())){
builder.append(" and total >= ? "); paramList.add(Integer.parseInt(courseType.getTotalStart()));
} if(StringUtils.isNotBlank(courseType.getTotalEnd())){
builder.append(" and total <= ? "); paramList.add(Integer.parseInt(courseType.getTotalEnd()));
}
//4.费用 if(StringUtils.isNotBlank(courseType.getLessonCostStart())){
builder.append(" and courseCost >= ? "); paramList.add(Double.parseDouble(courseType.getLessonCostStart()));
} if(StringUtils.isNotBlank(courseType.getLessonCostEnd())){
builder.append(" and courseCost <= ? "); paramList.add(Double.parseDouble(courseType.getLessonCostEnd()));
}
String condition = builder.toString();
Object[] params = paramList.toArray();
/////////////////////////////////////////
//2.分页
//2.1总记录数
int totalRecord = this.courseTypeDao.getTotalRecord(condition,params);
//2.2创建对象
PageBean<CrmCourseType> pageBean = new PageBean<CrmCourseType>(pageNum, pageSize, totalRecord);
//2.3分页数据
List<CrmCourseType> data = this.courseTypeDao.findAllCourseType(condition, params,pageBean.getStartIndex(),pageBean.getPageSize());
pageBean.setData(data);
return pageBean;
}4.dao层的实现
public int getTotalRecord(String condition, Object[] params) {
String hql = "select count(c) from CrmCourseType c where 1 = 1 "+condition;
List<Long> list = this.getHibernateTemplate().find(hql,params);
return list.get(0).intValue();
}
public List<CrmCourseType> findAllCourseType(String condition,
Object[] params, int startIndex, int pageSize) {
String hql = "from CrmCourseType where 1=1 " + condition;
return this.getHibernateTemplate().execute(new PageHibernateCallback<CrmCourseType>().setHql(hql).setParams(params).setStartIndex(startIndex).setPageSize(pageSize));
}5.hql语句中的find不能实现分页，要重写其方法
private String hql;
private Object[] params;
private int startIndex;
private int pageSize;
public PageHibernateCallback<T> setHql(String hql) {
this.hql = hql;
return this;
}
public PageHibernateCallback<T> setParams(Object[] params) {
this.params = params;
return this;
}
public PageHibernateCallback<T> setStartIndex(int startIndex) {
this.startIndex = startIndex;
return this;
}
public PageHibernateCallback<T> setPageSize(int pageSize) {
this.pageSize = pageSize;
return this;
}
@Override
public List<T> doInHibernate(Session session) throws HibernateException,
SQLException {
//1.通过hql语句，获得Query对象
Query queryObject = session.createQuery(hql);
//2.条件设置
for (int i = 0; i < params.length; i++) {
queryObject.setParameter(i, params[i]);
}
//3.分页
queryObject.setFirstResult(startIndex);
queryObject.setMaxResults(pageSize);
//4.查询所有
return queryObject.list();
}
6.Page domain的实现
//必选项
private int pageNum; //当前页
private int pageSize; //每页显示个数（固定值）
private int totalRecord;//总记录数（查询数据库）
//计算项
private int startIndex; //开始索引（计算）
private int totalPage; //总分页数（计算）
//数据
private List<T> data; //分页数据
//动态显示数据
private int start;
private int end;
//构造函数
public PageBean(int pageNum, int pageSize, int totalRecord) {
super();
this.pageNum = pageNum;
this.pageSize = pageSize;
this.totalRecord = totalRecord;
//计算
this.startIndex = (this.pageNum - 1) * this.pageSize;
this.totalPage = (this.totalRecord + this.pageSize - 1 ) / this.pageSize;
//1.初始化--显示10个分页
this.start = 1;
this.end = 10;
//2.初始化数据，---totalPage
if(this.end > this.totalPage){
this.end = this.totalPage;
}else{
//totalPage=22
//当前页，前4后5
this.start = pageNum - 4;
this.end = pageNum + 5;
//pageNum = 1
if(this.start <1){
this.start = 1;
this.end = 10;
}
//pageNum ==22
if(this.end > totalPage){
this.end = totalPage;
this.start = totalPage - 9;
}
}