文章目录
- 一、JSP概述
- 二、JSP快熟入门
- 导入JSP坐标
- 编写HTML文件和Java代码
- 三、JSP原理
- 四、JSP脚本
- JSP脚本案例
- 五、JSP缺点
- 六、EL表达式
- 七、JSTL标签
- 1、<c:if>标签
- 2、<c:foerEach>标签
- 八、MVC 模式和三层架构
- 1、MVC 模式
- 2、三层架构
- 3、MVC 模式和三层架构的区别
一、JSP概述
二、JSP快熟入门
导入JSP坐标
<dependency><groupId>javax.servlet.jsp</groupId><artifactId>jsp-api</artifactId><version>2.2</version><scope>provided</scope></dependency>
编写HTML文件和Java代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>Title</title>
</head>
<body><h1>hello jsp</h1><%System.out.println("hello,jsp~");
%></body>
</html>
三、JSP原理
四、JSP脚本
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>Title</title>
</head>
<body><h1>hello jsp</h1><%System.out.println("hello,jsp~");int i = 3;
%><%="hello"%>
<%=i%><%!void show(){}String name = "zhangsan";
%>
</body>
</html>
JSP脚本案例
品牌实体类
package com.itheima.pojo;/*** 品牌实体类*/public class Brand {// id 主键private Integer id;// 品牌名称private String brandName;// 企业名称private String companyName;// 排序字段private Integer ordered;// 描述信息private String description;// 状态:0:禁用 1:启用private Integer status;public Brand() {}public Brand(Integer id, String brandName, String companyName, String description) {this.id = id;this.brandName = brandName;this.companyName = companyName;this.description = description;}public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {this.id = id;this.brandName = brandName;this.companyName = companyName;this.ordered = ordered;this.description = description;this.status = status;}// getId ${brand.id} Id getIdpublic Integer getId() {System.out.println("getId方法被调用了...");return id;}public void setId(Integer id) {this.id = id;}public String getBrandName() {return brandName;}public void setBrandName(String brandName) {this.brandName = brandName;}public String getCompanyName() {return companyName;}public void setCompanyName(String companyName) {this.companyName = companyName;}public Integer getOrdered() {return ordered;}public void setOrdered(Integer ordered) {this.ordered = ordered;}public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public Integer getStatus() {return status;}public void setStatus(Integer status) {this.status = status;}@Overridepublic String toString() {return "Brand{" +"id=" + id +", brandName='" + brandName + '\'' +", companyName='" + companyName + '\'' +", ordered=" + ordered +", description='" + description + '\'' +", status=" + status +'}';}
}
JSP页面
<%@ page import="com.itheima.pojo.Brand" %>
<%@ page import="java.util.List" %>
<%@ page import="java.util.ArrayList" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %><%// 查询数据库List<Brand> brands = new ArrayList<Brand>();brands.add(new Brand(1,"三只松鼠","三只松鼠",100,"三只松鼠,好吃不上火",1));brands.add(new Brand(2,"优衣库","优衣库",200,"优衣库,服适人生",0));brands.add(new Brand(3,"小米","小米科技有限公司",1000,"为发烧而生",1));%><!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<input type="button" value="新增"><br>
<hr>
<table border="1" cellspacing="0" width="800"><tr><th>序号</th><th>品牌名称</th><th>企业名称</th><th>排序</th><th>品牌介绍</th><th>状态</th><th>操作</th></tr><%for (int i = 0; i < brands.size(); i++) {Brand brand = brands.get(i);%><tr align="center"><td><%=brand.getId()%></td><td><%=brand.getBrandName()%></td><td><%=brand.getCompanyName()%></td><td><%=brand.getOrdered()%></td><td><%=brand.getDescription()%></td><%if(brand.getStatus() == 1){//显示启用%><td><%="启用"%></td><%}else {// 显示禁用%><td><%="禁用"%></td><%}%><td><a href="#">修改</a> <a href="#">删除</a></td></tr><%}%></table></body>
</html>
五、JSP缺点
六、EL表达式
EL代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>Title</title>
</head>
<body>${brands}</body>
</html>
Servlet代码
package com.itheima.web;import com.itheima.pojo.Brand;import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;@WebServlet("/demo1")
public class ServletDemo1 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 准备数据List<Brand> brands = new ArrayList<Brand>();brands.add(new Brand(1,"三只松鼠","三只松鼠",100,"三只松鼠,好吃不上火",1));brands.add(new Brand(2,"优衣库","优衣库",200,"优衣库,服适人生",0));brands.add(new Brand(3,"小米","小米科技有限公司",1000,"为发烧而生",1));//2. 存储到request域中request.setAttribute("brands",brands);request.setAttribute("status",1);//3. 转发到 el-demo.jsp//request.getRequestDispatcher("/el-demo.jsp").forward(request,response);//request.getRequestDispatcher("/jstl-if.jsp").forward(request,response);request.getRequestDispatcher("/jstl-foreach.jsp").forward(request,response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}
}
七、JSTL标签
1、<c:if>标签
导入jstl坐标
<!--jstl--><dependency><groupId>jstl</groupId><artifactId>jstl</artifactId><version>1.2</version></dependency><dependency><groupId>taglibs</groupId><artifactId>standard</artifactId><version>1.1.2</version></dependency>
<c:if>演示
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><html>
<head><title>Title</title>
</head>
<body><%--c:if:来完成逻辑判断,替换java if else--%>
<%--<c:if test="true"><h1> true</h1></c:if><c:if test="false"><h1> false</h1></c:if>
--%><c:if test="${status ==1}">启用</c:if><c:if test="${status ==0}">禁用</c:if></body>
</html>
2、<c:foerEach>标签
<c:foerEach>演示
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<input type="button" value="新增"><br>
<hr>
<table border="1" cellspacing="0" width="800"><tr><th>序号</th><th>品牌名称</th><th>企业名称</th><th>排序</th><th>品牌介绍</th><th>状态</th><th>操作</th></tr><c:forEach items="${brands}" var="brand" varStatus="status"><tr align="center"><%--<td>${brand.id}</td>--%><td>${status.count}</td><td>${brand.brandName}</td><td>${brand.companyName}</td><td>${brand.ordered}</td><td>${brand.description}</td><c:if test="${brand.status == 1}"><td>启用</td></c:if><c:if test="${brand.status != 1}"><td>禁用</td></c:if><td><a href="#">修改</a> <a href="#">删除</a></td></tr></c:forEach></table><hr><c:forEach begin="1" end="10" step="1" var="i"><a href="#">${i}</a>
</c:forEach></body>
</html>