浙江圣大建设集团有限公司网站,韩国游戏网站设计,国外家居设计网站,培训教育学校的网站建设方案0 JavaWeb项目目录
└──JavaWeb├──resources│ └──db.properties├──src│ └──com.sdust.web│ ├──servlet│ │ └──StudentServlet│ ├──pojo│ │ └──Student│ └──util│ └──JDBCUtil├──web│ ├──st…0 JavaWeb项目目录
└──JavaWeb├──resources│ └──db.properties├──src│ └──com.sdust.web│ ├──servlet│ │ └──StudentServlet│ ├──pojo│ │ └──Student│ └──util│ └──JDBCUtil├──web│ ├──static│ │ └──bootstrap-3.4.1-dist│ ├──WEB-INF│ │ ├──lib│ │ │ └──mysql-connector-j-8.0.31.jar│ │ └──web.xml│ ├──index.jsp│ └──student_list.jsp└──JavaWeb.imlbootstrap下载(美化包) mysql-connector-j-8.0.31.jar
1 IDEA、Tomcat环境搭建
1.1 版本
IDEAIntelliJ IDEA 2023.2.4 Tomcatapache-tomcat-9.0.87官方下载地址 用IDEA进行JavaWeb的话不需要配置Tomcat的环境变量下载后解压就可以用了。
1.2 IDEA2023如何将项目变成Web项目
1.2.1 Help中点击Find Action 1.2.2 搜索Add Framework Support 1.2.3 勾选Web Application 1.3 配置Tomcat Server
1.3.1 点击Edit Configurations 1.3.2 点击加号选择Tomcat Server Local 1.4 添加依赖 浏览器既可以访问JSP也可以访问Servlet但是绝大部分情况下浏览器不直接访问JSPJSP主要用来展示数据 所以绝大部分情况是先访问Servlet查找出数据来之后转发到JSP页面进行展示。 2 Student类与数据库表
2.1 Student类
/** 适度编码益脑沉迷编码伤身合理安排时间享受快乐生活。* Copyright TangXJ* Created by TangXJ* CreatedUsed date: 2024/4/2 上午11:31 ~ 2024/4/2 下午1:44* Modified date: 2024/4/2 下午1:44*/package com.sdust.web.pojo;public class Student {private Integer id;private String name;private Integer age;private String gender;public Student() {}public Student(Integer id, String name, Integer age, String gender) {this.id id;this.name name;this.age age;this.gender gender;}public Integer getId() {return id;}public void setId(Integer id) {this.id id;}public String getName() {return name;}public void setName(String name) {this.name name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age age;}public String getGender() {return gender;}public void setGender(String gender) {this.gender gender;}Overridepublic String toString() {return Student{ id id , name name \ , age age , gender gender \ };}
}
2.2 数据库student表 2.3 JDBCUtil
/** 适度编码益脑沉迷编码伤身合理安排时间享受快乐生活。* Copyright TangXJ* Created by TangXJ* CreatedUsed date: 2024/3/27 下午4:00 ~ 2024/4/2 下午1:40* Modified date: 2024/4/2 下午1:40*/package com.sdust.web.util;import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;public class JDBCUtil {private static String driver;private static String url;private static String username;private static String password;private JDBCUtil(){}//静态代码块在类加载的时候只会执行一次避免重复加载驱动 还没调方法就执行了//读取配置文件static {try {//1.通过当前的类获取类加载器ClassLoader classLoader JDBCUtil.class.getClassLoader();//反射 JVM会说 先当成固定的结论就行了//2.通过类加载器的方法获得一个输入流InputStream inputStream classLoader.getResourceAsStream(db.properties);//不是因为叫了resource是因为标识了Mark as//3.创建一个Properties对象 对配置文件的封装Properties properties new Properties();properties.load(inputStream);//配置文件//4.获取配置文件中的参数的值driver properties.getProperty(driver);url properties.getProperty(url);username properties.getProperty(username);password properties.getProperty(password);} catch (IOException e) {throw new RuntimeException(e);}try {Class.forName(driver);} catch (ClassNotFoundException e) {throw new RuntimeException(e);}}public static Connection getConnection() throws SQLException {Connection connection DriverManager.getConnection(url, username, password);return connection;/*Connection connection null;try {connection DriverManager.getConnection(jdbc:mysql://localhost:3306/study?useSSLfalseuseUnicodetruecharacterEncodingutf8serverTimezoneGMT%2b8, root, xiangjie);} catch (SQLException e) {throw new RuntimeException(e);}return connection;*/}public static void close(Connection connection, Statement statement, ResultSet resultSet) {if (resultSet ! null) {try {resultSet.close();} catch (SQLException e) {throw new RuntimeException(e);}}if (statement ! null) {try {statement.close();} catch (SQLException e) {throw new RuntimeException(e);}}if (connection ! null) {try {connection.close();} catch (SQLException e) {throw new RuntimeException(e);}}}
}
2.4 resources/db.properties
drivercom.mysql.cj.jdbc.Driver
urljdbc:mysql://localhost:3306/xxxx?useSSLfalseuseUnicodetruecharacterEncodingutf8serverTimezoneGMT%2b8
usernameroot
passwordxxxxx3 StudentServlet
WebServlet(/student)
public class StudentServlet extends HttpServlet {//默认访问serviceOverrideprotected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(StudentServlet.service);Connection connection null;PreparedStatement preparedStatement null;ResultSet resultSet null;ListStudent list new ArrayList();try {connection JDBCUtil.getConnection();String sql SELECT id,name,age,gender FROM student;//预编译preparedStatement connection.prepareStatement(sql);resultSet preparedStatement.executeQuery();while (resultSet.next()) {//判断下一个有没有如果返回true而且指向下一个没有返回falseint id resultSet.getInt(id);String name resultSet.getString(name);int age resultSet.getInt(age);String gender resultSet.getString(gender);Student student new Student(id, name, age, gender);list.add(student);}for (Student student : list) {System.out.println(student);}} catch (SQLException throwables) {throwables.printStackTrace();} finally {JDBCUtil.close(connection, preparedStatement, resultSet);}//把list数据放到req里面req.setAttribute(list, list);//转发到student_list.jsp页面进行展示req.getRequestDispatcher(student_list.jsp).forward(req, resp);}
}4 student_list.jsp
% page importcom.situ.web.pojo.Student %
% page importjava.util.List %
% page contentTypetext/html;charsetUTF-8 languagejava %
html
headtitleTitle/titlelink relstylesheet hrefstatic/bootstrap-3.4.1-dist/css/bootstrap.css
/head
body%//JSP页面中可以嵌套Java代码//JSP脚本在这里可以写任意的Java代码//request、response:JSP页面的内置对象ListStudent list (ListStudent) request.getAttribute(list);%table classtable table-striped table-bordered table-hover table-condensedtrtdID/tdtd名字/tdtd年龄/tdtd性别/tdtd编辑/tdtd删除/td/tr%for (Student student : list) {%trtd%student.getId()%/tdtd%student.getName()%/tdtd%student.getAge()%/tdtd%student.getGender()%/tdtd编辑/tdtd删除/td/tr%}%/table
/body
/html5 结果 6 tomcat中文乱码问题
6.1 方法一 添加一行代码-Dfile.encodingUTF-8 添加同样的一行代码-Dfile.encodingUTF-8
6.2 方法二
如果上面方法不管用请先删掉加了的代码再尝试方法二 按照路径找到logging.properties文件 有notepad就用notepad打开没有记事本打开就行 把所有的UTF-8编码改成GBK可以把原来的注释掉方便出现其他情况时改回。
7 代码
Day16_JSP、Servlet
