标签：odi void 自定义 博客 content mamicode url 使用 attribute
1.首页在我们通用分页1博客的基础上新建Servlet
package com.zking.web;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.zking.dao.BookDao;
import com.zking.entity.Book;
import com.zking.util.PageBean;
/**
* Servlet implementation class BookServet
*/
@WebServlet("/BookServet")
public class BookServet extends HttpServlet implements Servlet {
private static final long serialVersionUID = 1L;
private BookDao bookDao=new BookDao();
/**
* @see HttpServlet#HttpServlet()
*/
public BookServet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stubo
String bname=request.getParameter("bname");
Book book=new Book();
book.setBname(bname);
PageBean bean=new PageBean();
try {
bean.setRequest(request);
List<Book> list=this.bookDao.list(book, bean);
request.setAttribute("booklist", list);
request.setAttribute("pagebean",bean);
request.getRequestDispatcher("/book.jsp").forward(request, response);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
2.改造PageBen
package com.zking.util;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
/**
* 分页工具类
*
*/
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 Map<String, String[]> paMap=new HashMap<String, String[]>();
private String url;
public void setRequest(HttpServletRequest request) {
//保存上一次请求的所有参数
this.setPaMap( request.getParameterMap());
this.setUrl(request.getRequestURL().toString());
//在jsp页面来控制是否分页
this.setPagination(request.getParameter("pagination"));
//在jsp页面控制一页展示多少条
this.setRows(request.getParameter("rows"));
this.setPage(request.getParameter("page"));
}
private void setPage(String page) {
this.page=StringUtils.isNotBlank(page) ? Integer.valueOf(page) : this.page;
}
private void setPagination(String pagination) {
this.pagination=StringUtils.isNotBlank(pagination) ? !"false".equals(pagination) : this.pagination;
}
private void setRows(String rows) {
this.rows=StringUtils.isNotBlank(rows) ? Integer.valueOf(rows) : this.rows;
}
public Map<String, String[]> getPaMap() {
return paMap;
}
public void setPaMap(Map<String, String[]> paMap) {
this.paMap = paMap;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
private boolean pagination = true;// 是否分页
public PageBean() {
super();
}
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 + "]";
}
/**
* 获取最大的页面数
* @return
*/
public int getMaxPage() {
return this.total%this.rows==0 ? this.total/this.rows :(this.total/this.rows)+1;
}
/**
* 获取下一页
* @return
*/
public int getNextPage() {
return this.page<this.getMaxPage()? this.page+1:this.page;
}
/**
* 获取上一页
* @return
*/
public int getPreviousPage() {
return this.page>1 ? this.page-1:this.page;
}
}
3 创建自定义分页标签
3.1
新建助手类PageTag.java
package com.zking.tag;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;
import com.zking.util.PageBean;
public class PageTag extends BodyTagSupport {
private PageBean bean;
public PageBean getBean() {
return bean;
}
public void setBean(PageBean bean) {
this.bean = bean;
}
@Override
public int doStartTag() throws JspException {
JspWriter out= pageContext.getOut();
try {
out.print(tohtml());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return super.doStartTag();
}
private String tohtml() {
StringBuilder sb=new StringBuilder();
//拼接下一次发送请求所要提交的隐藏的form表单
sb.append("<form id=‘pageBeanForm‘ action=‘"+bean.getUrl()+"‘ method=‘post‘>");
sb.append(" <input type=‘hidden‘ name=‘page‘>");
Map<String, String[]> paMap = bean.getPaMap();
if(paMap!=null&&paMap.size()>0) {
Set<Entry<String, String[]>> entrySet = paMap.entrySet();
for (Entry<String, String[]> entry : entrySet) {
//上一次请求可能携带页面name=page的参数，但是改参数在前面已经单独赋值
//为什么要单独赋值呢？因为上一次请求是第一页的数据，下一次可能是第二页，因为这前后请求page对应的值是不一样的，要单独赋值
if(!"page".equals(entry.getKey())) {
for(String val:entry.getValue()) {
sb.append("<input type=‘hidden‘ name=‘"+entry.getKey()+"‘ value=‘"+val+"‘>");
}
}
}
}
sb.append(" </form>");
//拼接分页条
sb.append("<div style=‘text-align: right; font-size: 12px;‘>");
sb.append(" 每页"+bean.getRows()+"条，共"+bean.getTotal()+"条，第"+bean.getPage()+"页，共"+bean.getMaxPage()+"页 <a href=‘javascript:gotoPage(1)‘>首页");
sb.append(" </a> <a");
sb.append(" href=‘javascript:gotoPage("+bean.getPreviousPage()+")‘>上一页</a> <a");
sb.append(" href=‘javascript:gotoPage("+bean.getNextPage()+")‘>下一页</a> <a");
sb.append(" href=‘javascript:gotoPage("+bean.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>");
//拼接所需要的js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)>"+bean.getMaxPage()+"){");
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();
}
}
3.2创建tld文件index.tld(要与助手类的属性一一对应)
<tag>
<name>page</name>
<tag-class>com.zking.tag.PageTag</tag-class>
<body-content>JSP</body-content>
<attribute>
<name>bean</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
</tag>
4.掉用过滤器EncodingFiter.java处理中文乱码问题
@WebFilter(urlPatterns="/*")使用的是servlet3.0注解技术。
package com.zking.util;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 中文乱码处理
*
*/
@WebFilter(urlPatterns="/*")
public class EncodingFiter implements Filter {
private String encoding = "UTF-8";// 默认字符集
public EncodingFiter() {
super();
}
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
// 中文处理必须放到 chain.doFilter(request, response)方法前面
res.setContentType("text/html;charset=" + this.encoding);
if (req.getMethod().equalsIgnoreCase("post")) {
req.setCharacterEncoding(this.encoding);
} else {
Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合
Set set = map.keySet();// 取出所有参数名
Iterator it = set.iterator();
while (it.hasNext()) {
String name = (String) it.next();
String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]
for (int i = 0; i < values.length; i++) {
values[i] = new String(values[i].getBytes("ISO-8859-1"),
this.encoding);
}
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集
if (null != s && !s.trim().equals("")) {
this.encoding = s.trim();
}
}
}
5.新建jsp进行测试
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@page isELIgnored="false" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@taglib prefix="z" uri="/MyJSP" %>
<!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="${pageContext.request.contextPath}/BookServet"
method="post">
书名：<input type="text" name="bname"> <input type="submit"
value="确定">
</form>
<table border="1" width="100%">
<tr>
<td>编号</td>
<td>名称</td>
<td>价格</td>
</tr>
<c:forEach items="${booklist }" var="b">
<tr>
<td>${b.bid }</td>
<td>${b.bname }</td>
<td>${b.price }</td>
</tr>
</c:forEach>
</table>
<z:page bean="${pagebean }"></z:page>
</body>
</html>
结果如下
所有数据展示
模糊查询结果
查询所有的第二页数据
尾页数据
这就是一个整体的一个单表通用分页效果
主要就是将上一次查询请求再发一次
String contextPath = req.getContextPath();//根目录
String url = req.getServletPath();//请求的地址
req.getRequestURL() //获取请求全路径
Map<String, String[]> parameterMap = req.getParameterMap();//获得请求中的所有参数
注1：不能将分页表单嵌套到其它表单中，否则不能提交表单！！！
标签：odi void 自定义 博客 content mamicode url 使用 attribute
原文地址：https://www.cnblogs.com/xmf3628/p/11069982.html
