[PHP知识库]2021-09-02

思维导图

?

补充知识：1.解决配置文件可随意更改问题

1.配置的文件位置：web.xml

@Override
	public void init() throws ServletException {
		try {
			configModel = ConfigModelFactory.build("/mvc.xml");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

2.配置xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>T266_MVC</display-name>
  <servlet>
  	<servlet-name>mvc</servlet-name>
  	<servlet-class>com.zking.framework.DispatchServlet</servlet-class>
  	<init-param>
  		<param-name>configurationLocation</param-name>
  		<param-value>/mvc.xml</param-value>
  	</init-param>
  </servlet>
  <servlet-mapping>
  	<servlet-name>mvc</servlet-name>
  	<url-pattern>*.action</url-pattern>
  </servlet-mapping>
</web-app>

3.再做个判断，等于Null或者等于" " 给它一个默认的值

@Override
	public void init() throws ServletException {
		try {
            String configurationLacation=this.getInitParameter("configurationLacation");
            if(configurationLacation==null||"".equals(configurationLacation)){
                configurationLacation="/zking.xml";
            }
			configModel = ConfigModelFactory.build("/mvc.xml");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

2.利用框架开发项目

1.导入框架的jar? ：点击framework包右键选中Export在弹出的框里收缩jar file

2.配置框架的相关配置文件

①mvc.xml放到源文件夹下方

②在web.xml中配置mvc.xml,让中央控制器加载mvc.xml建模

3.业务开发

①实体类entiy

②Dao层：1.写sql 2.建立连接 3.预定义对象PreparedStatement 4.设置参数 5.执行sql

③Web层子控制器

④View层JSP

3.完整版增删查改

页面展示：

?修改后：

?

增加后：

删除后：

?

?代码展示：

BookDao类：

	public void add(Book book) throws Exception {
		String sql  = "insert into t_book values(?,?,?)";
		super.executeUpdate(sql, book, new String[] {"bid","bname","price"});
	}
	
	public void delete(Book book) throws Exception {
		String sql  = "delete from t_book where bid = ?";
		super.executeUpdate(sql, book, new String[] {"bid"});
	}
	
	public void edit(Book book) throws Exception {
		String sql  = "update t_book set bname = ?,price = ? where bid = ?";
		super.executeUpdate(sql, book, new String[] {"bname","price","bid"});
	}
	
	public List<Book> list(Book book,PageBean pageBean) throws Exception {
		String sql  = "select * from t_book where 1=1 ";
		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);
	}
	

web层

子控制器必须继承ActionSupport实现模型驱动接口

public class BookAction extends ActionSupport implements ModelDriver<Book>{

}

1.增删改返回toList? ? ? ? 2.查询返回toList? ? ? ? 3.回显返回toEdit

private Book book = new Book();
	private BookDao bookDao = new BookDao();
	@Override
	public Book getModel() {
		return book;
	}
	
	public String add(HttpServletRequest req, HttpServletResponse resp) {
		try {
			bookDao.add(book);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "toList";
	}
	
	public String delete(HttpServletRequest req, HttpServletResponse resp) {
		try {
			bookDao.delete(book);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "toList";
	}
	
	public String edit(HttpServletRequest req, HttpServletResponse resp) {
		try {
			bookDao.edit(book);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "toList";
	}
	
	public String list(HttpServletRequest req, HttpServletResponse resp) {
		PageBean pageBean = new PageBean();
		pageBean.setRequest(req);
		try {
			List<Book> list = bookDao.list(book, pageBean);
			req.setAttribute("books", list);
			req.setAttribute("pageBean", pageBean);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "list";
	}
	
	public String toEdit(HttpServletRequest req, HttpServletResponse resp) {
		if(book.getBid() != 0) {
			try {
				List<Book> list = bookDao.list(book, null);
				req.setAttribute("b", list.get(0));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return "toEdit";
	}

View层

<%@ 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 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">
<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>书籍列表</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="${pageContext.request.contextPath }/book.action?methodName=list" method="post">
		<div class="form-group mb-2">
			<input type="text" class="form-control-plaintext" name="bname"
				placeholder="请输入书籍名称">
<!-- 			<input name="rows" value="20" type="hidden"> -->
<!-- 不想分页 -->
				<input name="pagination" value="false" type="hidden">
		</div>
		<button type="submit" class="btn btn-primary mb-2">查询</button>
		<a class="btn btn-primary mb-2" href="${pageContext.request.contextPath }/book.action?methodName=toEdit">新增</a>
	</form>

	<table class="table table-striped">
		<thead>
			<tr>
				<th scope="col">书籍ID</th>
				<th scope="col">书籍名</th>
				<th scope="col">价格</th>
				<th scope="col">操作</th>
			</tr>
		</thead>
		<tbody>
			<c:forEach  var="b" items="${books }">
			<tr>
				<td>${b.bid }</td>
				<td>${b.bname }</td>
				<td>${b.price }</td>
				<td>
					<a href="${pageContext.request.contextPath }/book.action?methodName=toEdit&bid=${b.bid}">修改</a>
					<a href="${pageContext.request.contextPath }/book.action?methodName=delete&bid=${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>

</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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>
<form action="${pageContext.request.contextPath }/book.action?methodName=${empty b ? 'add' : 'edit'}" method="post">
	bid:<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>
</html>

注意：！！！? ? 问题

运行完页面会出现报错? ：http://localhost:8080/T266_mvc_crud/bookList.jsp

?解决方法：

应当在界面输入：http://localhost:8080/T266_mvc_crud/book.action?methodName=list