ssh框架在图书管理系统练习中的分页操作

添加分页工具类PageBean及dao层操作工具类

public class PageBean<T> {

private Integer pageNo=1;// 当前页码数

private Integer pageByCount=3;// 每页显示的行数

private Integer total;// 总记录数

private Integer pageTotal;// 总页数

private List<T> lists;//当前页面数据对象的集合

public List<T> getLists() {

return lists;

}

public void setLists(List<T> lists) {

this.lists = lists;

}

public Integer getPageNo() {

return pageNo;

}

public void setPageNo(Integer pageNo) {

if (pageNo<1) {

this.pageNo = 1;

} else if (pageNo>this.pageTotal&&this.pageTotal>0) {

this.pageNo=this.pageTotal;

}else{

this.pageNo = pageNo;

}

public Integer getPageByCount() {

return pageByCount;

}

public void setPageByCount(Integer pageByCount) {

this.pageByCount = pageByCount;

}

public Integer getTotal() {

return total;

}

public void setTotal(Integer total) {

this.total = total;

//计算出总页数

this.pageTotal=(this.total%this.pageByCount==0)?(this.total/this.pageByCount):(this.total/this.pageByCount+1);

}

public Integer getPageTotal() {

return pageTotal;

}

public void setPageTotal(Integer pageTotal) {

this.pageTotal = pageTotal;

}

/**

* 数据访问层的基类

* @author Administrator

* @param <T>

public interface BaseDao<T> {

public void save(T instances);

public void delete(T instances);

public void update(T instances);

@SuppressWarnings("rawtypes")

public Object findById(Class clazz ,Integer id) ;

/**

* 查询所有用户列表

public List<T> findAll();

/**

* 查询所有用户列表

* @param clazz

@SuppressWarnings("rawtypes")

public List<Object> findAll(Class clazz);

/**

* 根据HQL查询数据

* @param hql

* @return 实体对象列表

@SuppressWarnings("rawtypes")

public List findByHql(String hql) ;

/**

* 根据对象名和对象属性获取对象集合

* @param className

* @param propertyName

* @param value

* @return

public List<T> findByProperty(String className,String propertyName, Object value);

/**

* 实现分页获取数据的功能

* @param hql 查询数据的HQL

* @return Object[0]当前页的数据列表List、Object[1]总页数、Object[2]总记录数

public Object[] findPageByHql(final String hql, String hqlCount, final int page, final int pageSize);

/**

* 获取分页对象，实现分页获取数据的功能

* @param hql 查询数据的HQL

* @return Page对象包含当前页的数据列表List、总页数、总数量和页数集合

public PageBean<T> findPageByHql(final String hql, String hqlCount, PageBean<T> page);

}

public interface BookDao extends BaseDao<Book> {

}

@Component

public class BaseDaoImpl<T> implements BaseDao<T> {

private Log log = LogFactory.getLog(this.getClass());

private Class<T> entityClass1;

private String entityClass;

private HibernateTemplate hibernateTemplate;

@SuppressWarnings("unchecked")

public BaseDaoImpl() {

//entityClass = GenericsUtils.getSuperClassGenricType(getClass(), 0);

Class c = this.getClass();

Type t = c.getGenericSuperclass();

if (t instanceof ParameterizedType) {

Type[] p = ((ParameterizedType) t).getActualTypeArguments();

this.entityClass1 = (Class<T>) p[0];

entityClass=entityClass1.getName();

}

@Resource

public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {

this.hibernateTemplate = hibernateTemplate;

}

public void save(T instance) {

log.debug("saving " + instance + " instance");

try {

hibernateTemplate.save(instance);

log.debug("save successful");

} catch (RuntimeException re) {

log.error("save failed", re);

throw re;

}

public void delete(T instance) {

log.debug("deleting "+instance+" instance");

try {

hibernateTemplate.delete(instance);

log.debug("delete successful");

} catch (RuntimeException re) {

log.error("delete failed", re);

throw re;

}

public void update(T instance) {

log.debug("updating "+instance+" instance");

try {

hibernateTemplate.update(instance);

log.debug("update successful");

} catch (RuntimeException re) {

log.error("update failed", re);

throw re;

}

@SuppressWarnings("rawtypes")

public Object findById(Class clazz, Integer id) {

log.debug("getting "+clazz+" instance with id: " + id);

try {

Object object=hibernateTemplate.get(clazz, id);

return object;

} catch (RuntimeException re) {

log.error("get failed", re);

throw re;

}

@SuppressWarnings("unchecked")

public List<T> findAll() {

log.debug("getting "+entityClass+" List All ");

try {

String hql = "FROM "+entityClass;

Query queryObject = hibernateTemplate.getSessionFactory().getCurrentSession().createQuery(hql);

System.out.println("........aaaaaaaaaaaa.....");

return queryObject.list();

} catch (RuntimeException re) {

System.out.println(re.toString());

log.error("find by HQL ", re);

throw re;

}

@SuppressWarnings({ "unchecked", "rawtypes" })

public List findAll(Class clazz) {

log.debug("getting "+clazz+" List All ");

try {

String c = clazz.toString();

String hql = "FROM "

+ c.substring(c.lastIndexOf(".") + 1, c.length());

Query queryObject = hibernateTemplate

.getSessionFactory().getCurrentSession().createQuery(hql);

return queryObject.list();

} catch (RuntimeException re) {

log.error("find by HQL ", re);

throw re;

}

/**

* 根据对象名和对象属性查询数据

* @param className

* @param propertyName

* @param value

* @return 实体对象列表

@SuppressWarnings("unchecked")

public List<T> findByProperty(String className,String propertyName, Object value) {

log.debug("finding "+className+" instance with property: " + propertyName + ", value: " + value);

try {

String hql = "FROM " + className + " as o WHERE o." + propertyName

+ " = ?";

//getSession()?

Query queryObject = hibernateTemplate

.getSessionFactory().getCurrentSession().createQuery(hql);

queryObject.setParameter(0, value);

return queryObject.list();

} catch (RuntimeException re) {

log.error("find by property name failed", re);

throw re;

}

/**

* 根据HQL查询数据

* @param hql

* @return 实体对象列表

@SuppressWarnings("rawtypes")

public List findByHql(String hql) {

log.debug(hql);

try {

Query queryObject =hibernateTemplate

.getSessionFactory().getCurrentSession().createQuery(hql);

return queryObject.list();

} catch (RuntimeException re) {

log.error("find by HQL ", re);

throw re;

}

/**

* 获取分页对象，实现分页获取数据的功能

* @param hql 查询数据的HQL

* @param page 需要显示数据的页码

* @param pageSize 每页数据量

* @return Object[0]当前页的数据列表List ,Object[1]总页数，Object[2]总数量

@SuppressWarnings("rawtypes")

public Object[] findPageByHql(final String hql, String hqlCount, final int page, final int pageSize) {

log.debug(hql);

List list = new ArrayList();

Long total = new Long(0);

Integer totalPage = 0;

try {

//1、根据hql语句查询指定数据

Query qList = hibernateTemplate.getSessionFactory()

.getCurrentSession().createQuery(hql);

qList.setFirstResult(page * pageSize);

qList.setMaxResults(pageSize);

list = qList.list();

//2、根据hql语句查询总记录数

List listCount = findByHql(hqlCount);

if(listCount!=null && listCount.size()>0){

total = (Long)listCount.get(0);

}

//3、根据总记录数计算出总页数

totalPage = (int) Math.ceil((double) total.longValue() / pageSize);

} catch (Exception e) {

e.printStackTrace();

}

return new Object[] { list, totalPage, total };

}

/**

* 获取分页对象，实现分页获取数据的功能

* @param hql 查询数据的HQL

* @param page 分页对象

* @return page 分页对象

@SuppressWarnings({ "rawtypes", "unchecked" })

public PageBean<T> findPageByHql( String hql, String hqlCount, PageBean<T> page) {

log.debug(hql);

System.out.println("................"+hql);

try {

if(page !=null){

//1、根据hql语句查询指定数据

Query qList = hibernateTemplate.getSessionFactory()

.getCurrentSession().createQuery(hql);

//规律:(当前页码数-1）*每页显示的行数+1

int first=(page.getPageNo()-1)*page.getPageByCount();

qList.setFirstResult(first);

qList.setMaxResults(page.getPageByCount());

page.setLists(qList.list());//将数据集合保存到page对象

//2、根据hql语句查询总记录数

List listCount = findByHql(hqlCount);

if(listCount!=null && listCount.size()>0){

page.setTotal(Integer.parseInt(String.valueOf(listCount.get(0))));

}

} catch (Exception e) {

e.printStackTrace();

}

return page;

}

@Component

@SuppressWarnings("unchecked")

public class BookDaoImpl extends BaseDaoImpl<Book> implements BookDao {

}

public interface BookTypeDao extends BaseDao<BookType> {

}

@Component

@SuppressWarnings("unchecked")

public class BookTypeDaoImpl extends BaseDaoImpl<BookType> implements BookTypeDao {

}

/**

* 图书业务逻辑层接口

* @author Administrator

public interface BookService {

PageBean<Book> list_book(PageBean<Book> pageBean,String type,String name,String borrow);

}

@Service

public class BookTypeServiceImpl implements BookTypeService {

@Autowired

private BookTypeDao bookTypeDao;

@Override

public List<BookType> queryType() {

return bookTypeDao.findAll();

}

public class BookAction extends ActionSupport implements SessionAware {

private static final long serialVersionUID = 1L;

@Autowired

private BookService bookService;

@Autowired

private BookTypeService bookTypeService;

private Map<String, Object> session;

private String booktype;

private String bookname;

private String isborrow;

private PageBean<Book> page=new PageBean<Book>();

private Integer pageno;//接收页面传递的当前页码数

private Integer total;//将第一次查询出来的总页码数传给PageBean类中pageTotal

public String queryBook() {

List<BookType> bookTypes= bookTypeService.queryType();

//通过index.jsp进入action pageno为null if未进入

// 分页进入action的时候 pageNo 有值, 调用setPageNo()方法设置的时候由于PageBean类中pageTotal为null会报空指针错

//所以分页查询的时候需要将第一次查询出来的总页码数传给PageBean类中pageTotal

if (total!=null) {

page.setPageTotal(total);

}

if (pageno !=null) {

page.setPageNo(pageno);

}

PageBean<Book> pageBean= bookService.list_book(page, booktype, bookname, isborrow);

session.put("bookTypes", bookTypes);

session.put("pageBean", pageBean);

return SUCCESS;

}

public BookService getBookService() {

return bookService;

}

public void setBookService(BookService bookService) {

this.bookService = bookService;

}

public BookTypeService getBookTypeService() {

return bookTypeService;

}

public void setBookTypeService(BookTypeService bookTypeService) {

this.bookTypeService = bookTypeService;

}

public String getBooktype() {

return booktype;

}

public void setBooktype(String booktype) {

this.booktype = booktype;

}

public String getBookname() {

return bookname;

}

public void setBookname(String bookname) {

this.bookname = bookname;

}

public String getIsborrow() {

return isborrow;

}

public void setIsborrow(String isborrow) {

this.isborrow = isborrow;

}

public Integer getPageno() {

return pageno;

}

public void setPageno(Integer pageno) {

this.pageno = pageno;

}

public Integer getTotal() {

return total;

}

public void setTotal(Integer total) {

this.total = total;

}

@Override

public void setSession(Map<String, Object> arg0) {

this.session=arg0;

}

编写struts.xml

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

"http://struts.apache.org/dtds/struts-2.3.dtd">

</action>

</package>

</struts>

编写页面

<body>

</body>

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

function doPage(pageno){

//.给表单的当前也那么赋值

$("#pageno").val(pageno);

//提交查询的表单

$("#query").submit();

}

function changecheckBox(check){

$("input[name='bookid']").attr("checked",check);

}

function deleteAll() {

$("#delete").submit();

}

</script>

<title>Insert title here</title>

</head>

<body>

图书分类<select name="booktype">

<c:forEach items="${bookTypes}" var="type">

<option value="${type.id}" <c:if test="${type.id==btype}">selected="selected"</c:if> >${type.type_name}</option>

</c:forEach>

</select>

  图书名称<input name="bookname" value="${bookname}" >

 是否借阅<select name="isborrow">

<option value="0" <c:if test="${isborrow==0 }">selected="selected" </c:if> >未借阅</option>

<option value="1" <c:if test="${isborrow==1 }">selected="selected" </c:if>>已借阅</option>

</select>

</form>

<table>

<tr>

</tr>

<c:forEach items="${pageBean.lists}" var="book">

<tr>

<td>${book.bookType.type_name }</td>

<td>${book.book_author }</td>

<td>${book.publish_press }</td>

<td><c:if test="${book.is_borrow ==0 }">未借阅</c:if> <c:if

test="${book.is_borrow ==1 }">已借阅</c:if></td>

</tr>

</c:forEach>

<tr>

${pageBean.pageNo}/${pageBean.pageTotal}页</td>

</tr>

</table>

</form>

</div>

</body>

</html>

太复杂了，老老实实学习ssm，使用ssm的pagehelper助手吧。。。

ssh框架在图书管理系统练习中的分页操作

添加分页工具类PageBean及dao层操作工具类

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