web前端快速入门（五） JSP从入门到实栈

大黄烽
1,615 阅读4分钟

本人已参与[新人创作礼]活动，一起开启掘金创作之路。

在这里插入图片描述

一、JSP快速入门

在这里插入图片描述

二、JSP原理

在这里插入图片描述

三、JSP脚本

在这里插入图片描述 在这里插入图片描述

四、EL表达式

在这里插入图片描述

五、JSTL标签

在这里插入图片描述

使用c:if

在这里插入图片描述

package cn.hncj.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;
    }

    public Integer getId() {
        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;
    }

    @Override
    public String toString() {
        return "Brand{" +
                "id=" + id +
                ", brandName='" + brandName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}







package cn.hncj.web;

import cn.hncj.pojo.Brand;

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 java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created on 2022/3/26.
 *
 * @author Hou chaof
 */
@WebServlet("/demo1")
public class ServletDemo1 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //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", 1));
        brands.add(new Brand(2, "优衣库", "优衣库", 200, "优衣库，好", 0));
        brands.add(new Brand(3, "小米", "小米公司", 1000, "科技好！", 1));
        //存储到request域中
        req.setAttribute("brands",brands);//名称brands，第二个参数brands为List集合中的brands
        req.setAttribute("status",1);
        //转发到el-demo.jsp
        req.getRequestDispatcher("/jstl-if.jsp").forward(req,resp);


    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}



<%--
  Created by IntelliJ IDEA.
  User: houchaofeng
  Date: 2022/3/26
  Time: 21:16
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page isELIgnored="false"%>
<html>
<head>
    <title>Title</title>
</head>
<body>

  <%--c:if 用来完成逻辑判断，替换Java 中的 if else语句--%>
  <c:if test="${status==1}">
      启用
  </c:if>
  <c:if test="${status==0}">
    禁用
  </c:if>
</body>
</html>


项目成功运行，demo1页面出现：启用

使用c:foreach

在这里插入图片描述

package cn.hncj.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;
    }

    public Integer getId() {
        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;
    }

    @Override
    public String toString() {
        return "Brand{" +
                "id=" + id +
                ", brandName='" + brandName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}





package cn.hncj.web;

import cn.hncj.pojo.Brand;

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 java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created on 2022/3/26.
 *
 * @author Hou chaof
 */
@WebServlet("/demo1")
public class ServletDemo1 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //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", 1));
        brands.add(new Brand(2, "优衣库", "优衣库", 200, "优衣库，好", 0));
        brands.add(new Brand(3, "小米", "小米公司", 1000, "科技好！", 1));
        //存储到request域中
        req.setAttribute("brands",brands);//名称brands，第二个参数brands为List集合中的brands
        req.setAttribute("status",1);
        //转发到el-demo.jsp
//        req.getRequestDispatcher("/jstl-if.jsp").forward(req,resp);
        req.getRequestDispatcher("/jstl-foreach.jsp").forward(req,resp);


    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}


<%--
  Created by IntelliJ IDEA.
  User: houchaofeng
  Date: 2022/3/26
  Time: 21:34
  To change this template use File | Settings | File Templates.
--%>
<%@ 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="${brands}" var="brand">
        <tr align="center">
            <td>${brand.id}</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>

</body>
</html>

页面输出如下：

在这里插入图片描述

六、MVC模式和三层架构

在这里插入图片描述

在这里插入图片描述

七、案例

在这里插入图片描述

在这里插入图片描述

7.1准备环境

在这里插入图片描述

7.2查询所有

在这里插入图片描述 在这里插入图片描述

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.hncj</groupId>
    <artifactId>brand-demo</artifactId>
    <version>1.0</version>
    <packaging>war</packaging>
    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.9</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
            <scope>provided</scope>
        </dependency>
        <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>
    </dependencies>

</project>

package cn.hncj.mapper;

import cn.hncj.pojo.Brand;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 * Created on 2022/3/28.
 *
 * @author Hou chaof
 */
public interface BrandMapper {
    //查询所有
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List<Brand> selectAll();
}






package cn.hncj.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;
    }

    public Integer getId() {
        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;
    }

    @Override
    public String toString() {
        return "Brand{" +
                "id=" + id +
                ", brandName='" + brandName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}










package cn.hncj.service;

import cn.hncj.mapper.BrandMapper;
import cn.hncj.pojo.Brand;
import cn.hncj.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import java.util.List;

/**
 * Created on 2022/3/28.
 *
 * @author Hou chaof
 */
public class BrandService {
    SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    /**
    * Description:查询所有
    * @date:2022/3/28 10:07
    * @params: []
    * @return: java.util.List<cn.hncj.pojo.Brand>
    */
    public List<Brand> selectAll() {
        //调用BrandMapper.selectAll()

        //获取sqlSession
        SqlSession sqlSession = factory.openSession();
        //获取brandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
        //调用方法
        List<Brand> brands = mapper.selectAll();
        sqlSession.close();
        return brands;
    }
}





package cn.hncj.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        //静态代码块会随着类的加载而自动执行，且只执行一次

        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}






package cn.hncj.web;

import cn.hncj.pojo.Brand;
import cn.hncj.service.BrandService;

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 java.io.IOException;
import java.util.List;

/**
 * Created on 2022/3/28.
 *
 * @author Hou chaof
 */
@WebServlet("/selectAllServlet")
public class SelectAllServlet extends HttpServlet {
    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //调用BrandService完成查询

        List<Brand> brands = brandService.selectAll();
        //存入req域中
        req.setAttribute("brands", brands);
        //转发到brand.jsp中
        req.getRequestDispatcher("/brand.jsp").forward(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.hncj.mapper.BrandMapper">
        
    <resultMap id="brandResultMap" type="brand">
        <result column="brand_name" property="brandName"></result>
        <result column="company_name" property="companyName"></result>
    </resultMap>
</mapper>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--起别名-->
    <typeAliases>
        <package name="cn.hncj.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///db1?useSSL=false&amp;useServerPrepStmts=true"/>
                <property name="username" value="root"/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--扫描mapper-->
        <package name="cn.hncj.mapper"/>
    </mappers>
</configuration>

<%--
  Created by IntelliJ IDEA.
  User: houchaofeng
  Date: 2022/3/26
  Time: 21:34
  To change this template use File | Settings | File Templates.
--%>
<%@ 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="80%">
    <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="${brands}" var="brand">
        <tr align="center">
            <td>${brand.id}</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>

</body>
</html>

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>title</title>
</head>
<body>
    <a href="/selectAllServlet">查询所有</a>
</body>
</html>

在这里插入图片描述

在这里插入图片描述

avatar
文章
阅读
粉丝