使用扩展HibernateDaoSupport实现分页技术总结
mport java.sql.SQLException;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
public class MyHibernateDaoSupport extends HibernateDaoSupport {
public List findByPage(final String hql,final int offset,final int pageSize)
{
List list=this.getHibernateTemplate().executeFind(new HibernateCallback()
{
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List result=session.createQuery(hql).setFirstResult(offset).setMaxResults(pageSize).list();
return result;
}
}
);
return list;
}
public List findByPage(final String hql,final String value,final int offset,final int pageSize)
{
List list=this.getHibernateTemplate().executeFind(new HibernateCallback()
{
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
List result=session.createQuery(hql).setParameter(0,value).setFirstResult(offset).setMaxResults(pageSize).list();
return result;
}
}
);
return list;
}
public List findByPage(final String hql,final Object[] values,final int offset,final int pageSize){
List list=this.getHibernateTemplate().executeFind(new HibernateCallback()
{
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Query query=session.createQuery(hql);
for(int i=0;i<values.length;i++)
{
query.setParameter(i,values[i]);
}
List result=query.setFirstResult(offset).setMaxResults(pageSize).list();
return result;
}
}
);
return list;
}
}
2.定义要分页的实体的Dao接口
如：
public interface StudentDao {
Student get(int id);
void save(Student student);
void update(Student student);
void delete(int id);
void delete(Student student);
List<Student> findAll();
List<Student> findAllByPage(int pageNo,int pageSize);
int getStudentCount();
List<Student> findStudentByNameAndNumber(String stuName,String stuNumber);
}
3.定义实现类
主要写出两个分页中要用到的方法
public List<Student> findAllByPage(int pageNo, int pageSize) {
if(pageNo<1){
return null;
}
int offset=(pageNo-1)*pageSize;
return findByPage("from Student", offset, pageSize);
}
public int getStudentCount() {
List<Student> listStudent=this.getHibernateTemplate().find("from Student");
return listStudent.size();
}
4.定义Service接口
public interface ExamService {
int STUDENT_PAGE_SIZE=3;
int QUESTION_PAGE_SIZE=3;
int addStudent(String stuNumber,String name,String className,String humanId,String email,String address,String phone) throws Exception;
void deleteStudent(int id) throws Exception;
List<Student> listStudent(int pageNo) throws Exception;
int addQuestion(String quTitle,String quHard,String quScore,String quAnswer,String quType,String selectOption,int typeid) throws Exception;
void deleteQuestion(int id) throws Exception;
List<Question> listQuestion(int pageNo) throws Exception;
void deleteExamtype(int typeid) throws Exception;
int addExamtype(String textName,String testTime)throws Exception;
List<Examtype> getAllExamtype()throws Exception;
boolean adminLogin(String admName,String admPwd)throws Exception;
int getStudentCount()throws Exception;
int getQuestionCount()throws Exception;
int getPageCount(int count,int pageSize);
String studentLogin(String stuName,String stuNumber)throws Exception;
Question getNextQuestion(List<Integer> alreadys,int typeid)throws Exception;
Question getQuestionById(int id)throws Exception;
String getExamtypeName(int typeid)throws Exception;;
}
5.定义实现类
public int getPageCount(int count, int pageSize) {
return (count+pageSize-1)/pageSize;
}
public int getStudentCount() throws Exception {
return studentDao.getStudentCount();
}
public List<Student> listStudent(int pageNo) throws Exception {
return studentDao.findAllByPage(pageNo, STUDENT_PAGE_SIZE);
}
6.ListStudentAction.javaint studentCount=examService.getStudentCount();
ActionMessages errors=new ActionMessages();
if(studentCount<1)
{
errors.add("studentCount",new ActionMessage("studentCount.null"));
mapping.findForward("success");
}
int pageCount=examService.getPageCount(studentCount,examService.STUDENT_PAGE_SIZE);
int pageNo;
if(request.getParameter("pageNo")==null || request.getParameter("pageNo").trim().equals(""))
{
pageNo=1;
}
try {
pageNo=Integer.parseInt(request.getParameter("pageNo").trim());
} catch (Exception e) {
pageNo=1;
}
if(pageNo>pageCount){
pageNo=pageCount;
}
request.setAttribute("pageCount",pageCount);
request.setAttribute("currentPage",pageNo);
request.setAttribute("studentList", examService.listStudent(pageNo));
return mapping.findForward("success");
7.listStudent.jsp
<table cellspacing="0" cellpadding="0" border="1" width="700">
<tr>
<th>
<bean:message key="student.shenfenzheng" />
</th>
<th>
<bean:message key="student.mingzi" />
</th>
<th>
<bean:message key="student.banji" />
</th>
<th>
<bean:message key="student.xuehao" />
</th>
<th>
<bean:message key="student.youjian" />
</th>
<th>
<bean:message key="student.dianhua" />
</th>
<th>
<bean:message key="student.address" />
</th>
<th>
<bean:message key="student.isdelete" />
</th>
</tr>
<c:forEach items="${requestScope.studentList}" var="students">
<tr>
<td align="center">
${students.humanId}
</td>
<td align="center">
${students.stuName}
</td>
<td align="center">
${students.stuClassName}
</td>
<td align="center">
${students.stuNumber}
</td>
<td align="center">
${students.email}
</td>
<td align="center">
${students.phone}
</td>
<td align="center">
${students.address}
</td>
<td align="center">
<a href="deleteStudent.do?delStuid=${students.id}"
onclick='return confirm("<bean:message key="confirm.del.student"/>");' target="center"><bean:message
key="student.delete" />
</a>
</td>
</tr>
</c:forEach>
<br />
<tr>
<td colspan="7" align="center">
第${requestScope.currentPage}页 共${requestScope.pageCount}页
<a href="listStudent.do?pageNo=1">首页</a>
<logic:greaterThan value="1" name="currentPage" scope="request">
<a href="listStudent.do?pageNo=${requestScope.currentPage-1}">
</logic:greaterThan>
上一页
<logic:greaterThan value="1" name="currentPage" scope="request">
</a>
</logic:greaterThan>
<logic:lessThan value="${requestScope.pageCount}" name="currentPage"
scope="request">
<a href="listStudent.do?pageNo=${requestScope.currentPage+1}">
</logic:lessThan>
下一页
<logic:lessThan value="${requestScope.pageCount}" name="currentPage"
scope="request">
</a>
</logic:lessThan>
<a href="listStudent.do?pageNo=${requestScope.pageCount}">尾页</a>
</td>
</tr>
</table>
