一.公共页面的跳转
1.编写页面跳转控制类
package com.YU.web;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
/**
* @author YU
* @create 2023-09-07 14:41
*/
@Controller
public class PageController {
@RequestMapping("/page/{page}")
public String toPage(@PathVariable("page") String page){
return page;
}
@RequestMapping("/page/{dir}{page}")
public String toDirPage(
@PathVariable("dir") String dir,
@PathVariable("page") String page){
return dir + "/" + page;
}
}
二.后端实现crud
1.利用mybatis插件生成实体模型和mapper接口和xml文件
在生成后的HBookMapper接口中，需要加上@Repository给Spring进行托管
2.编写切面类和工具类
2.1切面类：
package com.YU.aspect;
import com.YU.utils.PageBean;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
import java.util.List;
/**
* @author YU
* @create 2023-08-25 17:17
*/
@Aspect //代表当前类为切面类
@Component //代表当前类交给Spring进行管理
public class PagerAspect {
@Around("execution(* *..*biz.*Pager(..))")
public Object invoke(ProceedingJoinPoint args) throws Throwable {
PageBean pageBean = null;
//获取目标方法的所有参数
Object[] ars = args.getArgs();
for (Object param : ars) {
if(param instanceof PageBean){
pageBean = (PageBean)param;
break;
}
}
if(pageBean != null && pageBean.isPagination())
PageHelper.startPage(pageBean.getPage(),pageBean.getRows());
Object list = args.proceed();
if(null != pageBean && pageBean.isPagination()){
PageInfo pageInfo = new PageInfo((List) list);
pageBean.setTotal((int) pageInfo.getTotal());
}
return list;
}
}
2.2 工具类
package com.YU.utils;
import javax.servlet.http.HttpServletRequest;
import java.io.Serializable;
import java.util.Map;
public class PageBean implements Serializable {
private static final long serialVersionUID = 2422581023658455731L;
//页码
private int page=1;
//每页显示记录数
private int rows=10;
//总记录数
private int total=0;
//是否分页
private boolean isPagination=true;
//上一次的请求路径
private String url;
//获取所有的请求参数
private Map<String,String[]> map;
public PageBean() {
super();
}
//设置请求参数
public void setRequest(HttpServletRequest req) {
String page=req.getParameter("page");
String rows=req.getParameter("rows");
String pagination=req.getParameter("pagination");
this.setPage(page);
this.setRows(rows);
this.setPagination(pagination);
this.url=req.getContextPath()+req.getServletPath();
this.map=req.getParameterMap();
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public Map<String, String[]> getMap() {
return map;
}
public void setMap(Map<String, String[]> map) {
this.map = map;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public void setPage(String page) {
if(null!=page&&!"".equals(page.trim()))
this.page = Integer.parseInt(page);
}
public int getRows() {
return rows;
}
public void setRows(int rows) {
this.rows = rows;
}
public void setRows(String rows) {
if(null!=rows&&!"".equals(rows.trim()))
this.rows = Integer.parseInt(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 isPagination;
}
public void setPagination(boolean isPagination) {
this.isPagination = isPagination;
}
public void setPagination(String isPagination) {
if(null!=isPagination&&!"".equals(isPagination.trim()))
this.isPagination = Boolean.parseBoolean(isPagination);
}
/**
* 获取分页起始标记位置
* @return
*/
public int getStartIndex() {
//(当前页码-1)*显示记录数
return (this.getPage()-1)*this.rows;
}
/**
* 末页
* @return
*/
public int getMaxPage() {
int totalpage=this.total/this.rows;
if(this.total%this.rows!=0)
totalpage++;
return totalpage;
}
/**
* 下一页
* @return
*/
public int getNextPage() {
int nextPage=this.page+1;
if(this.page>=this.getMaxPage())
nextPage=this.getMaxPage();
return nextPage;
}
/**
* 上一页
* @return
*/
public int getPreivousPage() {
int previousPage=this.page-1;
if(previousPage<1)
previousPage=1;
return previousPage;
}
@Override
public String toString() {
return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", isPagination=" + isPagination
+ "]";
}
}
3.编写biz层
package com.YU.biz;
import com.YU.model.HBook;
import com.YU.utils.PageBean;
import java.util.List;
public interface HBookbiz {
int deleteByPrimaryKey(Integer bid);
int insert(HBook record);
int insertSelective(HBook record);
HBook selectByPrimaryKey(Integer bid);
int updateByPrimaryKeySelective(HBook record);
int updateByPrimaryKey(HBook record);
List<HBook> listPager(HBook hBook, PageBean pageBean);
}注：
这个方法为查询返回列表方法，包含分页，因为切面类对其进行切面，所以在命名时，必须以Pager结尾
4.配置mapper.xml
<select id="selectBycon" resultType="com.YU.model.HBook" parameterType="com.YU.model.HBook" >
select
<include refid="Base_Column_List" />
from t_mvc_book
<where>
<if test="bname != null">
and bname like concat('%',#{bname},'%')
</if>
</where>
</select>5.编写相应的接口类（HBookMapper）
List<HBook> selectBycon(HBook hBook);6.处理controller层发送到biz的请求(配置spring-mvc.xml)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--1) 扫描com.YU.web及子子孙孙包下的控制器(扫描范围过大，耗时)-->
<context:component-scan base-package="com.YU"/>
<!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
<mvc:annotation-driven />
<!--3) 创建ViewResolver视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView"></property>
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--4) 单独处理图片、样式、js等资源 -->
<!-- <mvc:resources location="/css/" mapping="/css/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<mvc:resources location="WEB-INF/images/" mapping="/images/**"/>-->
<!--处理controller层发送请求到biz，会经过切面的拦截处理-->
<aop:aspectj-autoproxy/>
</beans>7.编写tag助手标签类
package com.YU.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.YU.utils.PageBean;
public class PageTag extends BodyTagSupport{
private PageBean pageBean;// 包含了所有分页相关的元素
public PageBean getPageBean() {
return pageBean;
}
public void setPageBean(PageBean pageBean) {
this.pageBean = pageBean;
}
@Override
public int doStartTag() throws JspException {
// 没有标签体，要输出内容
JspWriter out = pageContext.getOut();
try {
out.print(toHTML());
} catch (IOException e) {
e.printStackTrace();
}
return super.doStartTag();
}
private String toHTML() {
StringBuffer sb = new StringBuffer();
// 隐藏的form表单---这个就是上一次请求下次重新发的奥义所在
// 上一次请求的URL
sb.append("<form action='"+pageBean.getUrl()+"' id='pageBeanForm' method='post'>");
sb.append(" <input type='hidden' name='page'>");
// 上一次请求的参数
Map<String, String[]> paramMap = pageBean.getMap();
if(paramMap != null && paramMap.size() > 0) {
Set<Entry<String, String[]>> entrySet = paramMap.entrySet();
for (Entry<String, String[]> entry : entrySet) {
// 参数名
String key = entry.getKey();
// 参数值
for (String value : entry.getValue()) {
// 上一次请求的参数，再一次组装成了新的Form表单
// 注意：page参数每次都会提交，我们需要避免
if(!"page".equals(key)) {
sb.append(" <input type='hidden' name='"+key+"' value='"+value+"' >");
}
}
}
}
sb.append("</form>");
// 分页条
sb.append("<ul class='pagination justify-content-center'>");
sb.append(" <li class='page-item "+(pageBean.getPage() == 1 ? "disabled" : "")+"'><a class='page-link'");
sb.append(" href='javascript:gotoPage(1)'>首页</a></li>");
sb.append(" <li class='page-item "+(pageBean.getPage() == 1 ? "disabled" : "")+"'><a class='page-link'");
sb.append(" href='javascript:gotoPage("+pageBean.getPreivousPage()+")'><</a></li>");// less than 小于号
// sb.append(" <li class='page-item'><a class='page-link' href='#'>1</a></li>");
// sb.append(" <li class='page-item'><a class='page-link' href='#'>2</a></li>");
sb.append(" <li class='page-item active'><a class='page-link' href='#'>"+pageBean.getPage()+"</a></li>");
sb.append(" <li class='page-item "+(pageBean.getPage() == pageBean.getMaxPage() ? "disabled" : "")+"'><a class='page-link' href='javascript:gotoPage("+pageBean.nextPage()+")'>></a></li>");
sb.append(" <li class='page-item "+(pageBean.getPage() == pageBean.getMaxPage() ? "disabled" : "")+"'><a class='page-link' href='javascript:gotoPage("+pageBean.maxPage()+")'>尾页</a></li>");
sb.append(" <li class='page-item go-input'><b>到第</b><input class='page-link'");
sb.append(" type='text' id='skipPage' name='' /><b>页</b></li>");
sb.append(" <li class='page-item go'><a class='page-link'");
sb.append(" href='javascript:skipPage()'>确定</a></li>");
sb.append(" <li class='page-item'><b>共"+pageBean.getTotal()+"条</b></li>");
sb.append("</ul>");
// 分页执行的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) > "+pageBean.getMaxPage()+") {");
sb.append(" alert('请输入1~"+pageBean.getMaxPage()+"的数字');");
sb.append(" return;");
sb.append(" }");
sb.append(" gotoPage(page);");
sb.append(" }");
sb.append("</script>");
return sb.toString();
}
}
8.引入tld标签库
<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version="2.0">
<description>YU 1.1 core library</description>
<display-name>YU core</display-name>
<tlib-version>1.1</tlib-version>
<short-name>YU</short-name>
<uri>http://jsp.veryedu.cn</uri>
<tag>
<name>page</name>
<tag-class>com.YU.tag.PageTag</tag-class>
<body-content>JSP</body-content>
<attribute>
<name>pageBean</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
</tag>
</taglib>
9.编写controller类
package com.YU.web;
import com.YU.biz.HBookbiz;
import com.YU.model.HBook;
import com.YU.utils.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.http.HttpServletRequest;
import java.util.List;
/**
* @author YU
* @create 2023-09-07 16:07
*/
@Controller
@RequestMapping("book")
public class HbookController {
@Autowired
private HBookbiz hBookbiz;
//增加
@RequestMapping("/add")
public String add(HBook hBook){
hBookbiz.insertSelective(hBook);
return "redirect:/book/list";
}
//删除
@RequestMapping("/del/{bid}")
public String del(@PathVariable("bid")Integer bid){
hBookbiz.deleteByPrimaryKey(bid);
return "redirect:/book/list";
}
//修改
@RequestMapping("/edit")
public String edit(HBook hBook){
hBookbiz.updateByPrimaryKeySelective(hBook);
return "redirect:list";
}
//查询
@RequestMapping("/list")
public String list(HBook hBook, HttpServletRequest request){
// hbook用来接收前台传递后台的参数
PageBean pageBean = new PageBean();
pageBean.setRequest(request);
List<HBook> hBooks = hBookbiz.listPager(hBook, pageBean);
request.setAttribute("lst",hBooks);
request.setAttribute("pageBean",pageBean);
return "book/list";
}
//数据回显
@RequestMapping("/preSave")
public String preSave(HBook hBook, Model model){
if(hBook !=null && hBook.getBid()!=null && hBook.getBid()!=0){
HBook b = hBookbiz.selectByPrimaryKey(hBook.getBid());
model.addAttribute("b",b);
}
return "book/edit";
}
}
10.编写前端页面
1.主页面(展示数据进行操作)
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://jsp.veryedu.cn" prefix="z"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link
href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
rel="stylesheet">
<script
src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js"></script>
<title>博客列表</title>
<style type="text/css">
.page-item input {
padding: 0;
width: 40px;
height: 100%;
text-align: center;
margin: 0 6px;
}
.page-item input, .page-item b {
line-height: 38px;
float: left;
font-weight: 400;
}
.page-item.go-input {
margin: 0 10px;
}
</style>
</head>
<body>
<form class="form-inline"
action="${pageContext.request.contextPath }/book/list" method="get">
<div class="form-group mb-2">
<input type="text" class="form-control-plaintext" name="cname"
placeholder="请输入班级名称">
<!-- <input name="rows" value="20" type="hidden"> -->
<!-- 不想分页 -->
<%-- <input name="pagination" value="false" type="hidden">--%>
</div>
<button type="submit" class="btn btn-primary mb-2">查询</button>
<a class="btn btn-primary mb-2" href="${pageContext.request.contextPath }/book/preSave">新增</a>
</form>
<table class="table table-striped">
<thead>
<tr>
<th scope="col">书籍ID</th>
<th scope="col">书籍名称</th>
<th scope="col">书籍价格</th>
<%-- <th scope="col">班级图片</th>--%>
<th scope="col">操作</th>
</tr>
</thead>
<tbody>
<c:forEach var="b" items="${lst }">
<tr>
<td>${b.bid }</td>
<td>${b.bname }</td>
<td>${b.price }</td>
<td>
<a href="${pageContext.request.contextPath }/book/preSave?bid=${b.bid}">修改</a>
<a href="${pageContext.request.contextPath }/book/del/${b.bid}">删除</a>
</td>
</tr>
</c:forEach>
</tbody>
</table>
<!-- 这一行代码就相当于前面分页需求前端的几十行了 -->
<z:page pageBean="${pageBean }"></z:page>
${pageBean }
</body>
</html>2.增加修改界面(操作数据)
<body>
<form action="${pageContext.request.contextPath }/${empty b ? 'book/add' : 'book/edit'}" method="post">
cid:<input type="text" name="bid" value="${b.bid }"><br>
bname:<input type="text" name="bname" value="${b.bname }"><br>
price:<input type="text" name="price" value="${b.price }"><br>
<input type="submit">
</form>
</body>3.测试结果
感谢各位大大的收看，各位的支持和三连是博主更新的动力，感谢谢谢谢！！！！
