目标 ：
完成t_mvc_book表的增删改查
1、通用分页的jar、自定义mvc框架、自定义标签
导入jar、导入之前写好的pageTag、自定义mvc.xml
2、dao层 通用的增删改方法
3、web层
mvc.xml进行配置
4、jsp
导入jar包：
工具类：
1、通用的增删改方法定义
BookDao.java
package com.huang.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.SQLException; import java.util.List; import com.huang.entity.Book; import com.huang.util.BaseDao; import com.huang.util.DBAccess; import com.huang.util.PageBean; import com.huang.util.StringUtils; public class BookDao extends BaseDao<Book> { public List<Book> list(Book book,PageBean pageBean) throws InstantiationException, IllegalAccessException, SQLException{ String sql="select * from t_mvc_book where true"; String bname=book.getBname(); int bid=book.getBid(); if(StringUtils.isNotBlank(bname)) { sql+="and bname like '%"+bname+"%'"; } if(bid !=0) { sql+="and bid="+bid; } return super.executeQuery(sql, Book.class, pageBean); } /** * 修改 * @param book * @return * @throws SQLException * @throws NoSuchFieldException * @throws SecurityException * @throws IllegalArgumentException * @throws IllegalAccessException */ public int edit (Book book) throws SQLException, NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException { String sql="update t_mvc_book set bname=? price=? where bid=?"; return super.executeUpdate(sql, new String[] {"bname","price","bid"}, book); } /** * 新增 * @param book * @return * @throws SQLException * @throws NoSuchFieldException * @throws SecurityException * @throws IllegalArgumentException * @throws IllegalAccessException */ public int add (Book book) throws SQLException, NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException { String sql="insert into t_mvc_book values(?,?,?)"; return super.executeUpdate(sql, new String[] {"bid","bname","price"}, book); } /** * 删除 * @param book * @return * @throws SQLException * @throws NoSuchFieldException * @throws SecurityException * @throws IllegalArgumentException * @throws IllegalAccessException */ public int del (Book book) throws SQLException, NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException { String sql="delete from t_mvc_book where bid=?"; return super.executeUpdate(sql, new String[] {"bid"}, book); } }
BaseDao.java
package com.huang.util; import java.lang.reflect.Field; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.huang.entity.Book; public class BaseDao<T> { /** * * @param sql 查询不同的实体类，那么对应的sql不同，所以需要传递 * @param clz 生产出不同的实体类对应的实例，然后装进list容器中返回 * @param pageBean 决定是否分页 * @return * @throws SQLException * @throws InstantiationException * @throws IllegalAccessException */ public List<T> executeQuery(String sql, Class clz,PageBean pageBean) throws SQLException, InstantiationException, IllegalAccessException{ Connection con = DBAccess.getConnection(); PreparedStatement pst = null; ResultSet rs =null; if(pageBean!=null&&pageBean.isPagination()) { //需要分页 //算符合条件的总记录数 String countSql=getCountSql(sql); pst=con.prepareStatement(countSql); rs=pst.executeQuery(); if(rs.next()) { pageBean.setTotal(rs.getLong(1)+""); } //算出符合条件的结果集 String pageSql=getPageSql(sql, pageBean); pst=con.prepareStatement(pageSql); rs=pst.executeQuery(); } else { pst=con.prepareStatement(sql); rs=pst.executeQuery(); } List<T> list=new ArrayList<>(); T t; while(rs.next()) { /** * 1、实例化一个book对象（该对象为空） * 2、取book的所有属性，然后给其赋值 * 2.1获取所有属性对象 * 2.2给属性对象赋值 * 3、赋完值的book对象装进list容器中 */ t=(T) clz.newInstance(); Field[] fields=clz.getDeclaredFields(); for (Field field : fields) { field.setAccessible(true); field.set(t, rs.getObject(field.getName())); } list.add(t); } DBAccess.close(con, pst, rs); return list; } /** * 利用原生sql拼接出符合条件的结果集的查询sql * @param sql * @param pageBean * @return */ private String getPageSql(String sql,PageBean pageBean) { return sql + " limit "+ pageBean.getStartIndex() +"," + pageBean.getRows(); } /** * 获取符合条件的总记录数的sql语句 * @param sql * @return */ private String getCountSql(String sql) { return "select count(*) from ("+ sql +") t"; } /** * * @param sql 增删改 * @param attrs 决定？位置 * @param t 要操作的实体类 * @return * @throws SQLException * @throws SecurityException * @throws NoSuchFieldException * @throws IllegalAccessException * @throws IllegalArgumentException */ public int executeUpdate(String sql,String[] attrs,T t) throws SQLException, NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException { Connection con=DBAccess.getConnection(); PreparedStatement pst=con.prepareStatement(sql); // pst.setString(2, book.getBname()); // pst.setFloat(3, book.getPrice()); // pst.setInt(1, book.getBid()); for (int i= 0; i <= attrs.length; i++) { Field f=t.getClass().getDeclaredField(attrs[i-1]); f.setAccessible(true); pst.setObject(i, f.get(t)); } int num=pst.executeUpdate(); DBAccess.close(con, pst, null); return num; } }
2、增删改查的jsp页面
BookAction.java
package com.huang.web; import java.sql.SQLException; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.huang.dao.BookDao; import com.huang.entity.Book; import com.huang.framework.ActionSupport; import com.huang.framework.ModelDrivern; import com.huang.util.PageBean; public class BookAction extends ActionSupport implements ModelDrivern<Book> { private Book book=new Book(); private BookDao bookDao=new BookDao(); /** * 分页查询 * @param req * @param resp * @return */ public String list(HttpServletRequest req,HttpServletResponse resp) { PageBean pageBean=new PageBean(); pageBean.setRequest(req); try { List<Book> list=this.bookDao.list(book, pageBean); req.setAttribute("bookList", list); req.setAttribute("pageBean", pageBean); } catch (InstantiationException | IllegalAccessException | SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "list"; } /** * 跳转到增加或者修改页面 * @param req * @param resp * @return * @throws InstantiationException * @throws IllegalAccessException * @throws SQLException */ public String preSave(HttpServletRequest req,HttpServletResponse resp) { // bid的类型是int类型，而int类型的默认值是0;如果jsp未传递bid的参数值，那么bid=0 if(book.getBid()==0) { System.out.println("增加逻辑...."); } else { // 修改数据回显逻辑 try { Book b=this.bookDao.list(book, null).get(0); req.setAttribute("book", b); } catch (InstantiationException | IllegalAccessException | SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return "edit"; } /** * 新增 * @param req * @param resp * @return */ public String add(HttpServletRequest req,HttpServletResponse resp) { try { this.bookDao.add(book); } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException | SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "toList"; } /** * 修改 * @param req * @param resp * @return */ public String edit(HttpServletRequest req,HttpServletResponse resp) { try { this.bookDao.edit(book); } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException | SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "toList"; } public String del(HttpServletRequest req,HttpServletResponse resp) { try { this.bookDao.del(book); } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException | SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "toList"; } @Override public Book getModel() { return book; } }
bookList.js
<%@ 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="my" uri="/huang" %>
<!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="${pageContext.request.contextPath}/book.action?methodName=list" method="post"> 书名：<input type="text" name="bname"> <input type="submit" value="确定"> </form> <a href="${pageContext.request.contextPath}/book.action?methodName=preSave">增加</a> <table border="1" width="100%"> <tr> <td>编号</td> <td>名称</td> <td>价格</td> <td>操作</td> </tr> <c:forEach items="${bookList }" var="b"> <tr> <td>${b.bid }</td> <td>${b.bname }</td> <td>${b.price }</td> <td> <a href="${pageContext.request.contextPath}/book.action?methodName=preSave&&bid=${b.bid}">修改</a> <a href="${pageContext.request.contextPath}/book.action?methodName=del&&bid=${b.bid}">删除</a> </td> </tr> </c:forEach> <z:page pageBean="${pageBean }"></z:page> </table> </body> </html>