1、pagebean实体类的改造
在通用分页_01的基础上加了两个参数url和paramMap集合
/**
* 分页工具类
*在通用分页_01中加了url和paramMap集合
*/
public class PageBean {
private int page = 1;// 页码
private int rows = 10;// 页大小
private int total = 0;// 总记录数
private boolean pagination = true;// 是否分页
private String url;
private Map<String, String[]> paramMap = new HashMap<>();
public void setRequest(HttpServletRequest req) {
this.setPage(req.getParameter("page"));
this.setRows(req.getParameter("rows"));
this.setPagination(req.getParameter("pagination"));
// getRequestURL获取到浏览器请求的全路径
this.setUrl(req.getRequestURL().toString());
// getParameterMap可以获取到一次url请求所携带的所有参数
this.setParamMap(req.getParameterMap());
}
public void setPagination(String pagination) {
if (StringUtils.isNotBlank(pagination)) {
this.setPagination(!"false".equals(pagination));
}
}
public void setRows(String rows) {
if (StringUtils.isNotBlank(rows))
this.setRows(Integer.valueOf(rows));
}
public void setPage(String page) {
if (StringUtils.isNotBlank(page)) {
this.setPage(Integer.valueOf(page));
}
}
public PageBean() {
super();
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public Map<String, String[]> getParamMap() {
return paramMap;
}
public void setParamMap(Map<String, String[]> paramMap) {
this.paramMap = paramMap;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getRows() {
return rows;
}
public void setRows(int rows) {
this.rows = rows;
}
public int getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
public void setTotal(String total) {
this.total = Integer.parseInt(total);
}
public boolean isPagination() {
return pagination;
}
public void setPagination(boolean pagination) {
this.pagination = pagination;
}
/**
* 获得起始记录的下标
*
* @return
*/
public int getStartIndex() {
return (this.page - 1) * this.rows;
}
@Override
public String toString() {
return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
}
/**
* 获取到总页数
* @return
*/
public int getMaxPage() {
return this.total % this.rows == 0 ?
this.total / this.rows :
(this.total / this.rows) + 1;
}
/**
* 获取下一页页码
* @return
*/
public int getNextPage() {
return this.page < this.getMaxPage() ? this.page+1 : this.page;
}
/**
* 获取上一页页码
* @return
*/
public int getPreviousPage() {
return this.page > 1 ? this.page-1 : this.page;
}
}
2、补全servlet
public class BookServlet extends HttpServlet {
private static final long serialVersionUID = 7357981557485986895L;
private BookDao bookDao = new BookDao();
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String bname = req.getParameter("bname");
Book book = new Book();
book.setBname(bname);
PageBean pagebean = new PageBean();
pagebean.setRequest(req);
try {
// 查询出符合条件的某一页的记录数
List<Book> list = bookDao.list(book, pagebean);
req.setAttribute("bookList", list);
req.setAttribute("pagebean", pagebean);
req.getRequestDispatcher("bookList.jsp").forward(req, resp);
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
3、视图层PageTag
public class PageTag extends BodyTagSupport {
private static final long serialVersionUID = -1739873776587683812L;
private PageBean pagebean;
@Override
public int doStartTag() throws JspException {
JspWriter out = pageContext.getOut();
try {
out.write(toHTML());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return super.doStartTag();
}
public String toHTML() {
StringBuffer sb = new StringBuffer();
// 下一次请求提交到后台的表单html代码拼接
sb.append("<form id='pageBeanForm' action='"+ pagebean.getUrl() +"' method='post'>");
Map<String, String[]> paramMap = pagebean.getParamMap();
if (paramMap != null && paramMap.size() > 0) {
for (Entry<String, String[]> entry : paramMap.entrySet()) {
if (!"page".equals(entry.getKey())) {
for(String val : entry.getValue()) {
sb.append("<input type='hidden' name='" + entry.getKey() + "' value='" + val + "' >");
}
}
}
}
sb.append(" <input type='hidden' name='page'>");
sb.append("</form>");
//分页条html代码拼接
sb.append("<div style='text-align: right; font-size: 12px;'>");
sb.append(" 每页"+pagebean.getRows()+"条，共"+pagebean.getTotal()+"条，第"+pagebean.getPage()+"页，共"+pagebean.getMaxPage()+"页 <a");
sb.append(" href='javascript:gotoPage(1)'>首页</a> <a");
sb.append(" href='javascript:gotoPage("+pagebean.getPreviousPage()+")'>上一页</a> <a");
sb.append(" href='javascript:gotoPage("+pagebean.getNextPage()+")'>下一页</a> <a");
sb.append(" href='javascript:gotoPage("+pagebean.getMaxPage()+")'>尾页</a> <input type='text'");
sb.append(" id='skipPage'");
sb.append(" style='text-align: center; font-size: 12px; width: 50px;'> <a");
sb.append(" href='javascript:skipPage()'>Go</a>");
sb.append("</div>");
//分页所需要调用的代码
sb.append("<script type='text/javascript'>");
sb.append(" function gotoPage(page) {");
sb.append(" document.getElementById('pageBeanForm').page.value = page;");
sb.append(" document.getElementById('pageBeanForm').submit();");
sb.append(" }");
sb.append(" function skipPage() {");
sb.append(" var page = document.getElementById('skipPage').value;");
sb.append(" if(!page || isNaN(page) || parseInt(page)<1 || parseInt(page)>maxPage){");
sb.append(" alert('请输入1~N的数字');");
sb.append(" return;");
sb.append(" }");
sb.append(" gotoPage(page);");
sb.append(" }");
sb.append(" </script>");
return sb.toString();
}
public PageBean getPagebean() {
return pagebean;
}
public void setPagebean(PageBean pagebean) {
this.pagebean = pagebean;
}
}
4、写tld配置page标签
<tag>
<!-- 标签库中的标签名 -->
<name>page</name>
<!-- 标签对应的助手类的全路径名 -->
<tag-class>com.zrh.tags.PageTag</tag-class>
<body-content>JSP</body-content>
<attribute>
<!-- 属性名 -->
<name>pagebean</name>
<!-- 属性值是否必填 -->
<required>true</required>
<!-- 是否支持表达式 -->
<rtexprvalue>true</rtexprvalue>
</attribute>
</tag>
5、页面展示
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="z" uri="/zrh" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h2>小说目录</h2>
<br>
<form action="${pageContext.request.contextPath}/bookServlet"
method="post">
书名：<input type="text" name="bname"> <input type="submit"
value="确定">
</form>
<table border="1" width="100%">
<tr>
<td>编号</td>
<td>名称</td>
<td>价格</td>
</tr>
<c:forEach items="${bookList }" var="b">
<tr>
<td>${b.bid }</td>
<td>${b.bname }</td>
<td>${b.price }</td>
</tr>
</c:forEach>
</table>
<z:page pagebean="${pagebean }"></z:page>
</body>
</html>
最后输出结果为：
