分页的实现

来源：互联网发布：ipad mini4必备软件编辑：程序博客网时间：2024/06/10 19:33

想要实现如下分页效果：

分页实现逻辑：

关键代码如下：

page.jsp

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

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

<html>

<head>

<title> Insert title here</title >

#pageCode{

width: 30px;

border: 1px solid black;

}

#current{

border: 1px solid black;

background-color: #bbffaa ;

}

</style>

$(function(){

//onchange在文本框内容发生改变时触发事件

$( "#pageCode").change(function (){

var pageCode=$.trim(this.value);

//如果输入为空

if(pageCode=="" ){

this.value=this .defaultValue;//恢复为默认值

return false ;

}

//如果输入值不是一个数字

if(isNaN(pageCode)){

this.value=this .defaultValue;//恢复为默认值

return false ;

}

//通过window.location对象实现页面的跳转

window.location.href= "DataServlet?method=getPage&pageNo=" +pageCode;

});

</script>

</head>

<body>

<c:forEach items="${page.list } " var ="data">

${data }<br >

</c:forEach >

<c:if test="${page.hasPrev } ">

</c:if >

<c:if test="${page.pageNo>3 } ">

</c:if >

<c:if test="${page.pageNo>4 } ">...</c:if >

<c:forEach begin="1" end= "${page.totalPageNum }" var="num" >

<c:choose>

<c:when test= "${num==page.pageNo }"><span id="current" >${num }</ span></c:when >

<c:when test= "${num>=page.pageNo-2 && num<=page.pageNo+2 }" >${num }  </c:when>

</c:choose>

</c:forEach >

<c:if test="${page.pageNo+3<page.totalPageNum }">...</c:if >

<c:if test="${page.pageNo+3<page.totalPageNum} ">

<a href="/Page/DataServlet?method=getPage&pageNo= ${page.totalPageNum}"> ${page.totalPageNum}</a >

</c:if >

<c:if test="${page.hasNext } ">

</c:if >

共有 ${page.totalItemNum }条记录

前往第 <input id= "pageCode" type ="text" name="pageCode" value="${page.pageNo } "/>页

</body>

</html>

DataServlet.java

public class DataServlet extends BaseServlet {

private static final long serialVersionUID = 1L ;

private DataService dataService = new DataServiceImpl();

protected void getDataList( HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

List <Data> dataList = dataService .getDataList() ;

WebUtils .forward( request, response , "dataList" , dataList, "/data.jsp" );

}

protected void getPage( HttpServletRequest request,

HttpServletResponse response) throws ServletException, IOException {

//获取页码

String pageNoStr = request.getParameter( "pageNo");

//获取Page对象

Page <Data> page = dataService.getPage (pageNoStr );

//传到前台去

//WebUtils.forward(request, response, attrName, attrVal, targetPath);

WebUtils .forward( request, response , "page" , page, "/page.jsp" );

}

BaseServlet .java

public abstract class BaseServlet extends HttpServlet {

private static final long serialVersionUID = 1L ;

@Override

protected void doGet( HttpServletRequest request, HttpServletResponse response )

throws ServletException, IOException {

doPost( request, response );

}

@Override

protected void doPost( HttpServletRequest request, HttpServletResponse response )

throws ServletException, IOException {

request .setCharacterEncoding( "UTF-8");

String methodName = request.getParameter( "method");

try {

Method method =

this. getClass() .getDeclaredMethod(

methodName ,

HttpServletRequest .class ,

HttpServletResponse .class

);

method .setAccessible( true);

method .invoke(this, request, response);

} catch (Exception e ) {

e .printStackTrace() ;

}

DataServiceImpl.java

public class DataServiceImpl implements DataService {

private DataDao dataDao = new DataDaoImpl ();

@Override

public List< Data> getDataList() {

return dataDao .getDataList() ;

}

@Override

public Page< Data> getPage(String pageNoStr) {

//1.取得总记录数

int totalItemNum = dataDao.getTotalItemNum ();

//2.通过参数pageNoStr和参数totalItemNum来创建page对象

//内部纠正了pageNo值

Page <Data> page= new Page<>(pageNoStr, totalItemNum);

//3.获取list数据，调用page.getPageNo()得到有效值

List <Data> list = dataDao.getPageList (page .getPageNo(), Page .pageSize) ;

page .setList(list);

//4.组装完page对象后将其返回

return page;

}

DataDaoImpl .java

public class DataDaoImpl extends DaoImpl <Data> implements DataDao {

@Override

public List< Data> getDataList() {

Connection connection = getConnection() ;

String sql = "select data_id dataId,data_name dataName from datatable";

List <Data> dataList = this .getBeanList (sql , connection);

releaseConn(connection );

return dataList;

}

@Override

public List< Data> getPageList(int pageNo, int pageSize) {

Connection connection = JDBCUtils.getConnection() ;

String sql = "SELECT data_id dataId,data_name dataName FROM datatable LIMIT ?,?";

List <Data> list = this .getBeanList (sql , connection, (pageNo - 1) *pageSize, pageSize);

JDBCUtils .releaseConn( connection);

return list;

}

@Override

public int getTotalItemNum() {

Connection connection = JDBCUtils.getConnection() ;

String sql = "SELECT COUNT(*) FROM datatable";

//执行count函数的SQL语句的Java函数返回的Java类型是Long

//将Long包装类型转换为long基本数据类型

long itemNum = this. getSigleValue(sql , connection);

JDBCUtils .releaseConn( connection);

//在返回时，将long基本数据类型强转为 int基本数据类型

return (int) itemNum;

}

DataDaoImpl.java

public class DataDaoImpl extends DaoImpl <Data> implements DataDao {

@Override

public List< Data> getDataList() {

Connection connection = JDBCUtils.getConnection() ;

String sql = "select data_id dataId,data_name dataName from datatable";

List <Data> dataList = this .getBeanList (sql , connection);

JDBCUtils .releaseConn( connection);

return dataList;

}

@Override

public List< Data> getPageList(int pageNo, int pageSize) {

Connection connection = JDBCUtils.getConnection() ;

String sql = "SELECT data_id dataId,data_name dataName FROM datatable LIMIT ?,?";

List <Data> list = this .getBeanList (sql , connection, (pageNo - 1) *pageSize, pageSize);

JDBCUtils .releaseConn( connection);

return list;

}

@Override

public int getTotalItemNum() {

Connection connection = JDBCUtils.getConnection() ;

String sql = "SELECT COUNT(*) FROM datatable";

//执行count函数的SQL语句的Java函数返回的Java类型是Long

//将Long包装类型转换为long基本数据类型

long itemNum = this. getSigleValue(sql , connection);

JDBCUtils .releaseConn( connection);

//在返回时，将long基本数据类型强转为 int基本数据类型

return (int) itemNum;

}

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