springboot02(系统学习）：yaml格式 多配置文件 springboot整合servlet springboo整合jsp springboo整合jdbc freemarker模板页

1 yaml

1.1 概念

YAML（/ˈjæməl/）是一个可读性高，用来描述数据的以数据为中心的语言(数据格式)
YAML是"YAML Ain't a Markup Language"的递归缩写。
这种语言以数据做为中心，而不是以标记语言为重点.  具备标记类语言的作用 但不具备标记类语言的特点
yaml不是标记类语言：：：不需要标签来封装数据
yaml是标记类语言：：：和标记类语言相同  都是用来描述数据

1.2 语法

    大小写敏感
    使用缩进表示层级关系
    缩进不允许使用tab，只允许空格
    缩进的空格数不重要，只要相同层级的元素左对齐即可
    '#'表示注释

2 yaml练习1

2.1 配置文件：application.yml

• 准备数据

# 注释

--- # 分割符号
stu1:
  # 单值属性
  sid: 1
  sage: 12
  sname: 韩梅梅
  sex: 女
  sdy: true
  sbirth: 2000-11-12

  # 数组属性：写法1： -
  arr1:
    - 1
    - 3
    - 6
    - 8
    - 11
    - 13
  # 数组属性：写法2： []
  arr2: [11.3,12.6,19.5,12,45,11,13]

  # 对象属性：写法1：yaml
  teacher1:
    tid: 1001
    tname: 张三
    tsubject: 数学
  # 对象属性：写法2：json
  teacher2: { tid: 1002,tname: "李四", tsubject: "语文" }

2.2 创建实体类

package com.zhiyou100.entity;

import java.io.Serializable;

public class Teacher  implements Serializable {
    private Integer tid;
    private String tname;
    private String tsubject;
    ...
}

package com.zhiyou100.entity;
...
@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)


@Component
@ConfigurationProperties(prefix = "stu1")
public class Student  implements Serializable {
    private Integer sid;
    private Integer sage;
    private String sname;
    private String sex;
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date sbirth;
    private Boolean sdy;
    private int[] arr1;
    private double[] arr2;

    private Teacher teacher1;
    private Teacher teacher2;
}

2.3 创建action 装配学生对象

package com.zhiyou100.action;
...
@RestController  //@Controller+@ResponseBody
@RequestMapping("/test01")
public class Test01 {
    @Autowired
    private Student student;
    @GetMapping("/m1.action")//@RequestMapping(value = "test01",method = RequestMethod.GET)
    public Student method01(){
        return student;
    }
}

2.4 结果

2.5 老师对象

• 配置文件：application.yml

• 实体类

@Component
@ConfigurationProperties(prefix = "stu1.teacher1")
public class Teacher  implements Serializable {
    private Integer tid;
    private String tname;
    private String tsubject;
    ...
}

• action

@Autowired
private Teacher teacher;
@GetMapping("/m2.action")//@RequestMapping(value = "test01",method = RequestMethod.GET)
public Teacher method02(){
    return teacher;
}

• 效果
  

3 属性集文件配置信息的读取

3.1 默认文件：application.properties

• 定义属性

• 实体类:写法1：通过注解@Value

@Component
public class Teacher2 implements Serializable {
    @Value("${teacher03.tid}")
    private Integer tid;
    @Value("${teacher03.tname}")
    private String tname;
    @Value("${teacher03.tsubject}")
    private String tsubject;
    ...
}

• 实体类:写法2：通过注解@ConfigurationProperties

@Component
@ConfigurationProperties(prefix = "teacher03")
public class Teacher2 implements Serializable {
    //@Value("${teacher03.tid}")
    private Integer tid;
    //@Value("${teacher03.tname}")
    private String tname;
    //@Value("${teacher03.tsubject}")
    private String tsubject;
    ...
}

• action

@Autowired
private Teacher2 teacher2;
@GetMapping("/m3.action")//@RequestMapping(value = "test01",method = RequestMethod.GET)
public Teacher2 method03(){
    return teacher2;
}

• 效果

3.2 自定义文件：config/hehe.properties

在启动类上加@PropertySource指定自定义配置文件的位置即可

• 配置文件：/config/hehe.properties

• 启动类

@SpringBootApplication
@PropertySource("classpath:config/hehe.properties")//加载非默认的配置文件：：：名字不是application
public class Springboot03Application {
    public static void main(String[] args) {
        SpringApplication.run(Springboot03Application.class, args);
    }
}

• 实体类

@Component
@ConfigurationProperties(prefix = "teacher04")
public class Teacher3 implements Serializable {
    private Integer tid;
    private String tname;
    private String tsubject;
    ...
}

• action

@Autowired
private Teacher3 teacher3;
@GetMapping("/m4.action")//@RequestMapping(value = "test01",method = RequestMethod.GET)
public Teacher3 method04(){
    return teacher3;
}

• 效果

3.3 总结

1 properties和yaml使用完全相同
2 如果是自定义配置文件 想被加载就需要在启动类上加@PropertySource
3 在实体类的属性上  可以通过@Value("${teacher03.tname}")指定要赋的值--从配置文件中读取
4 在实体类上       可以通过@ConfigurationProperties(prefix = "teacher03")指定要赋的前缀

4 配置文件

4.1 多配置文件

不同环境需要加载不同的信息：多个配置文件

• 创建文件：application-development.yml

server:
  port: 8082
  servlet:
    context-path: /springboot03_development

• 创建文件：application-produce.yml

server:
  port: 8083
  servlet:
    context-path: /springboot03_produce

• 创建文件：application-test.yml

server:
  port: 8081
  servlet:
    context-path: /springboot03_test

• 在核心配置文件application.yml 中 通过active属性设置要加载的配置文件的后缀

#  指定环境要使用的配置文件
spring:
  profiles:
    active: produce

4.2 一个配置文件多个环境

• 在核心配置文件中 通过— 设置多个环境 通过spring. config. activate.on-profile 来指定环境的名字

#指定环境使用的端配置信息的on-profile值
spring:
  profiles:
    active: t

--- # test环境
server:
  port: 8081
  servlet:
    context-path: /springboot03_test
spring:
  config:
    activate:
      on-profile: t

--- # development环境
server:
  port: 8082
  servlet:
    context-path: /springboot03_development
spring:
  config:
    activate:
      on-profile: d

--- # produce环境
server:
  port: 8082
  servlet:
    context-path: /springboot03_produce
spring:
  config:
    activate:
      on-profile: p

5 springboot整合servlet

引入springbootweb::springmvc和servlet可以共存

5.1 创建servlet:添加注解@WebServlet指定其url

package com.zhiyou100.action;

@WebServlet(urlPatterns = {"/test02/s1","/test02/s2","/test02/s3"})
public class Test02Servlet   extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         resp.getWriter().println("servlet::::::");
    }
}

5.2 启动类上加注解@ServletComponentScan扫描servlet

package com.zhiyou100;
...
@SpringBootApplication
@PropertySource("classpath:config/hehe.properties")//加载非默认的配置文件：：：名字不是application
@ServletComponentScan(basePackages = {"com.zhiyou100.action"})
public class Springboot03Application {
    public static void main(String[] args) {
        SpringApplication.run(Springboot03Application.class, args);
    }
}

6 springboot整合jdbc

6.1 创建项目

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-webartifactId>
dependency>

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>5.1.49version>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-testartifactId>
    <scope>testscope>
dependency>
<dependency>
    <groupId>org.projectlombokgroupId>
    <artifactId>lombokartifactId>
    <version>1.18.24version>
dependency>

6.2 数据库

CREATE TABLE `student` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `score` FLOAT DEFAULT NULL,
  `dy` BIT(1) DEFAULT NULL,
  `sex` VARCHAR(255) DEFAULT NULL,
  `name` VARCHAR(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=INNODB AUTO_INCREMENT=28 DEFAULT CHARSET=utf8;
INSERT INTO student VALUES(
    NULL,
    TRUNCATE(RAND()*100,1),
    RAND()>0.5,
    IF(RAND()>0.5,"男","女"),
    SUBSTRING(REPLACE(UUID(),"-",""),1,10));
SELECT * FROM student;

6.3 实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Student  implements Serializable {
    private Integer id;
    private String name;
    private String sex;
    private Float score;
    private Boolean dy;
}

6.4 dao

• 接口

public interface StudentDao {
    public List<Student> getAll();
    public Student getOne(int id);
    public List<Student> getSomeBySex(String sex);

    public int update(Student student);
    public int add(Student student);
    public int delete(int id);
}

• 实现类

package com.zhiyou100.dao;
...
@Repository
public class StudentDaoImp  implements  StudentDao{

    //获取jdbc模板类 //对jdbc的封装
    @Autowired
    private JdbcTemplate jdbcTemplate;
    //jdbcTemplate.update(sql,args);         //dml
    //jdbcTemplate.query(sql,rowmapper,args);//dql  rowmapper指定类中属性与表列的对应关系
    //jdbcTemplate.call();                   //调用函数和存储过程
    //jdbcTemplate.execute(sql) ;//可以执行dml 和 dql

    @Autowired
    //private RowMapper studentRowMapper;

    @Override
    public List<Student> getAll() {
        return  jdbcTemplate.query("select * from student",getRowMapper());
    }

    @Override
    public Student getOne(int id) {
        return jdbcTemplate.query("select * from student where id=?",getRowMapper(),id).get(0);
    }

    @Override
    public List<Student> getSomeBySex(String sex) {
        return jdbcTemplate.query("select * from student where sex=?",getRowMapper(),sex);
    }

    @Override
    public int update(Student s) {
        return jdbcTemplate.update("update student set sex=?,name=?,score=?,dy=? where id=?",s.getSex(),s.getName(),s.getScore(),s.getDy(),s.getId());
    }

    @Override
    public int add(Student s) {
        return jdbcTemplate.update("insert into student(name,sex,dy,score) values(?,?,?,?)",s.getName(),s.getSex(),s.getDy(),s.getScore());
    }

    @Override
    public int delete(int id) {
        return jdbcTemplate.update("delete from student where id=?",id);
    }

    //@Bean
    public RowMapper<Student> getRowMapper(){
        return new RowMapper<Student>(){
            @Override
            public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
                Student student =new Student();
                student.setId(rs.getInt("id"));
                student.setName(rs.getString("name"));
                student.setSex(rs.getString("sex"));
                student.setDy(rs.getBoolean("dy"));
                student.setScore(rs.getFloat("score"));
                return student;
            }
        };
    }
}

6.5 测试dao

@SpringBootTest
public class Test01StudentDao {

    @Autowired
    private StudentDao studentDao;

    @Test
    public void test01(){
        System.out.println(studentDao.getAll());
    }
}

6.6 service

• 接口
• 实现类

package com.zhiyou100.service;
...
@Service
public class StudentServiceImp  implements  StudentService{
    @Autowired
    private StudentDao studentDao;
    public List<Student> getAll(){
        return studentDao.getAll();
    }
    public Student getOne(int id){
        return studentDao.getOne(id);
    }
    public List<Student> getSomeBySex(String sex){
        return studentDao.getSomeBySex(sex);
    }

    public int update(Student student){
        return studentDao.update(student);
    }
    public int add(Student student){
        return studentDao.add(student);
    }
    public int delete(int id){
        return studentDao.delete(id);
    }
}

6.7 action

package com.zhiyou100.action;

import com.zhiyou100.entity.Student;
import com.zhiyou100.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.w3c.dom.stylesheets.LinkStyle;

import java.util.List;

@RestController
@RequestMapping("/student")
public class StudentAction {

    @Autowired
    private StudentService studentService;

    @RequestMapping("/getAll.action")
    public List<Student> getAll(){
        return studentService.getAll();
    }
    @RequestMapping("/getOne/{id}.action")
    public Student getOne(@PathVariable("id") int id){
        return studentService.getOne(id);
    }
    @RequestMapping("/getSomeBySex.action")
    public List<Student> getSomeBySex(String sex){
        return studentService.getSomeBySex(sex);
    }
    @RequestMapping("/update.action")
    public String update(Student student){
        int hang=studentService.update(student);
        return "修改"+hang+"行成功！";
    }
    @RequestMapping("/add.action")
    public String add(Student student){
        int hang=studentService.add(student);
        return "添加"+hang+"行成功！";
    }
    @RequestMapping("/delete/{id}.action")
    public String delete(@PathVariable("id") int id){
        int hang=studentService.delete(id);
        return "删除"+hang+"行成功！";
    }
}

6.8 浏览器测试即可

7 springboot整合jsp

7.1 创建springboot项目

7.2 引入依赖

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.7.3version>
        <relativePath/> 
    parent>
    <groupId>com.zhiyou100groupId>
    <artifactId>springboot05_jspartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>springboot05_jspname>
    <properties>
        <java.version>8java.version>
    properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>1.18.24version>
        dependency>


        
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>jstlartifactId>
        dependency>
        

        <dependency>
            <groupId>org.apache.tomcat.embedgroupId>
            <artifactId>tomcat-embed-jasperartifactId>
        dependency>

    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>

project>

7.3 创建文件夹 main/webapp/WEB-INF/jsps

7.4 指定web resources directory

project structure---选中当前项目的web--

7.5 通过idea的配置来添加web.xml

7.6 配置work directory

7.8 在核心配置文件中设置视图解析器

# 配置视图解析器
spring:
  mvc:
    view:
      prefix: /WEB-INF/jsps/
      suffix: .jsp

7.9 创建jsp

    


     
test01
     请求参数 age=${param.age}

     请求域属性 n=${requestScope.n}

     请求session id=${pageContext.session.id}

    


     
jstl表达式
      
              

          

              
学号
名字
政治
性别
分数
          
          

                  
${stu.id}
                  
${stu.name}
                  
${stu.dy}
                  
${stu.sex}
                  
${stu.score}
              
          
      

7.10 创建action

package com.zhiyou100.action;

import com.zhiyou100.entity.Student;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.ArrayList;
import java.util.List;

@RequestMapping("/test01")
@Controller
public class Test01 {
    @RequestMapping("/m1.action")
    public String method01(int age, Model model){
        model.addAttribute("n",System.currentTimeMillis());
        return "demo01";
    }

    @RequestMapping("/m2.action")
    public String method02(Model model){
        List<Student> list=new ArrayList<>();
        for (int i = 0; i <10 ; i++) {
            list.add(new Student(i+1,"韩梅梅"+i,i%2==0?"男":"女",i+10f,i%2==0));
        }
        model.addAttribute("list",list);
        return "demo02";
    }
}

• 实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Student  implements Serializable {
    private Integer id;
    private String name;
    private String sex;
    private Float score;
    private Boolean dy;
}

7.11 测试

8 使用springboot整合jdbc+jsp实现学生的crud

8.0 每个module整合jsp 都需要重新设置

参考段落7

8.1 创建springboot

8.2 添加依赖

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.7.3version>
        <relativePath/> 
    parent>
    <groupId>com.zhiyou100groupId>
    <artifactId>springboot06_jdbc_jspartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>springboot06_jdbc_jspname>
    <description>Demo project for Spring Bootdescription>
    <properties>
        <java.version>8java.version>
    properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jdbcartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.49version>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>

        
        
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>jstlartifactId>
        dependency>
        
        <dependency>
            <groupId>org.apache.tomcat.embedgroupId>
            <artifactId>tomcat-embed-jasperartifactId>
        dependency>
    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombokgroupId>
                            <artifactId>lombokartifactId>
                        exclude>
                    excludes>
                configuration>
            plugin>
        plugins>
    build>

project>

8.3 完善目录

8.4 设置支持jsp的三个操作

• 指定web resources directory
• 配置work directory
• 配置work directory

8.5 设置项目参数:核心配置文件

# 配置视图解析器
spring:
  mvc:
    view:
      prefix: /WEB-INF/jsps/
      suffix: .jsp
  # jdbc四大参数
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/db_1?charset=utf8
    username: root
    password: 123456

# 项目信息
server:
  servlet:
    context-path: /
  port: 8081

8.6 数据库

CREATE TABLE `student` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `score` FLOAT DEFAULT NULL,
  `dy` BIT(1) DEFAULT NULL,
  `sex` VARCHAR(255) DEFAULT NULL,
  `name` VARCHAR(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=INNODB AUTO_INCREMENT=28 DEFAULT CHARSET=utf8;
INSERT INTO student VALUES(
    NULL,
    TRUNCATE(RAND()*100,1),
    RAND()>0.5,
    IF(RAND()>0.5,"男","女"),
    SUBSTRING(REPLACE(UUID(),"-",""),1,10));
SELECT * FROM student;

8.7 实体类

package com.zhiyou100.entity;
...
@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Student   implements Serializable {
    private Integer id;
    private String name;
    private Float score;
    private String sex;
    private Boolean dy;
}

8.8 dao

package com.zhiyou100.dao;

import com.zhiyou100.entity.Student;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@Repository
@SuppressWarnings("all")
public class StudentDaoImp   implements  StudentDao{
    @Autowired
    private JdbcTemplate jdbcTemplate;
    public Student getOne(int id){
        return jdbcTemplate.query("select * from student where id=?",getMapper(),id).get(0);
    }
    public List<Student> getAll(){
        return jdbcTemplate.query("select * from student",getMapper());
    }
    public int add(Student s){
        return jdbcTemplate.update("insert into student(name,sex,score,dy) values(?,?,?,?)",s.getName(),s.getSex(),s.getScore(),s.getDy());
    }
    public int update(Student s){
        return jdbcTemplate.update("update student set name=?,sex=?,score=?,dy=? where id=?",s.getName(),s.getSex(),s.getScore(),s.getDy(),s.getId());
    }
    public int delete(int id){
        return jdbcTemplate.update("delete from student where id=?",id);
    }

    private RowMapper<Student> getMapper(){
        return new RowMapper<Student>() {
            @Override
            public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
                return new Student().setScore(rs.getFloat("score")).
                        setDy(rs.getBoolean("dy")).
                        setSex(rs.getString("sex")).
                        setName(rs.getString("name")).
                        setId(rs.getInt("id"));
            }
        };
    }
}

8.9 service

package com.zhiyou100.service;

import com.zhiyou100.dao.StudentDao;
import com.zhiyou100.entity.Student;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentServiceImp  implements  StudentService{
    @Autowired
    private StudentDao studentDao;

    @Override
    public Student getOne(int id) {
        return studentDao.getOne(id);
    }

    @Override
    public List<Student> getAll() {
        return studentDao.getAll();
    }

    @Override
    public int add(Student s) {
        return studentDao.add(s);
    }

    @Override
    public int update(Student s) {
        return studentDao.update(s);
    }

    @Override
    public int delete(int id) {
        return studentDao.delete(id);
    }
}

8.10 action

package com.zhiyou100.action;

import com.zhiyou100.entity.Student;
import com.zhiyou100.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/student")
public class StudentAction {
     @Autowired
    private StudentService studentService;

     @RequestMapping("/getAll.action")
     public String getAllMethod(Model model){
          model.addAttribute("list",studentService.getAll());
          return "student_manager";
     }
    @RequestMapping("/getOne/{id}.action")
    public String getOneMethod(@PathVariable("id") int id, Model model){
        model.addAttribute("stu",studentService.getOne(id));
        return "student_manager";
    }
    @RequestMapping("/update.action")
    public String updateMethod(Student student,Model model){
        studentService.update(student);
        model.addAttribute("message","修改成功！");
        return "student_manager";
    }
    @RequestMapping("/delete/{id}.action")
    public String deleteMethod(@PathVariable("id") int id, Model model){
        studentService.delete(id);
        model.addAttribute("message","删除成功！");
        return "student_manager";
    }
    @RequestMapping("/add.action")
    public String addMethod(Student student, Model model){
        studentService.add(student);
        model.addAttribute("message","添加成功！");
        return "student_manager";
    }
}

8.11 jsp

1 判断是否有list 没有list去action要
2 判断是否有提示信息 有就显示
3 显示list
4 创建一个表单 通过判断request域中是否有stu 来确定表单是添加还是修改

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


    
    
    


   
       
   
   
           
            

       

               

                    ${message}
               
           
       
       

           
学号
名字
分数
性别
政治
操作
       
       

                
${s.id}
                
${s.name}
                
${s.score}
                
${s.sex}
                

                    
                        
                            党员
                        
                        
                            群众
                        
                    
                
                

                    修改 |
                    删除
                
            
       
       

           

               
           
       
   
   

       
       

           

               
学生名字：
               

           
           

               
学生性别：
               

                   男： |
                   女：
               
           
           

               
学生分数：
               

           
           

               
政治面貌：
               
党员： |
                   群众：
           
           

               

                   
                   
               
           
       
   
   

8.12 定义action 能跳转此jsp

package com.zhiyou100.action;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class WebAction {
    @RequestMapping("/")
    public String welcome(){
        return "student_manager";
    }
}

8.13 效果

9 freemarker

9.0 参考

https://blog.csdn.net/weixin_44454512/article/details/109877418

9.1 概念

模板引擎（这里特指用于Web开发的模板引擎）是为了使用户界面与业务数据（内容）分离而产生的，它可以生成特定格式的文档，用于网站的模板引擎就会生成一个标准的HTML文档。

FreeMarker是一款模板引擎： 即一种基于模板和要改变的数据， 并用来生成输出文本（HTML网页、电子邮件、配置文件、源代码等）的通用工具。 它不是面向最终用户的，而是一个Java类库，是一款程序员可以嵌入他们所开发产品的组件。

学习和jsp完全相同：怎么获取数据+流程控制+函数

9.2 案例1: 获取域属性和请求参数

• 创建springboot项目

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-freemarkerartifactId>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-webartifactId>
dependency>

<dependency>
    <groupId>org.projectlombokgroupId>
    <artifactId>lombokartifactId>
    <optional>trueoptional>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-testartifactId>
    <scope>testscope>
dependency>

• 核心配置文件

spring.freemarker.tempalte-loader-path=classpath:/templates
spring.freemarker.cache=false
spring.freemarker.charset=utf-8
spring.freemarker.check-template-location=true
spring.freemarker.content-type=text/html
spring.freemarker.expose-request-attributes=true
spring.freemarker.expose-session-attributes=true
spring.freemarker.request-context-attribute=request
spring.freemarker.suffix=.ftl
#使用url模板映射需要设置此属性
spring.freemarker.allow-request-override=true

• action

package com.zhiyou100.action;

import com.zhiyou100.entity.Student;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import java.util.ArrayList;
import java.util.List;

@RequestMapping("/student")
@Controller
public class StudentAction {

    @RequestMapping("/getAll.action")
    public String getAll(HttpServletRequest req){
        List<Student>  list=new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            list.add(new Student(1000+i,"韩梅"+i,i+30f,i%2==0?"男":"女",i%2==0));
        }
        req.setAttribute("list",list);
        req.setAttribute("aa","a_request");
        req.getSession().setAttribute("bb","a_session");
        req.getServletContext().setAttribute("cc","a_application");
        //注意:属性名不能重复
        return "index01";
    }
}

• 实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Student   implements Serializable {
    private Integer id;
    private String name;
    private Float score;
    private String sex;
    private Boolean dy;
}

• 页面: /templates/index01.ftl

DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>第一个freemarker页面title>
head>
<body>
     <#--
        freemarker注释:: # - -
        freemarker中获取域属性:${内置对象["属性名"]}
        freemarker内置对象:::Request:::request域对象
                            Session:::session域对象
                            Application:::servletContext域对象
                            RequestParamters:::请求参数对象
        注意:属性名不能重复
     -->
     <h1>freemarker中:正常使用:js css htmlh1>
     <h1>freemarker中:获取域属性和请求参数h1>

      request域对象:a:::${Request["aa"]}<br/>
      session域对象:a:::${Session["bb"]}<br/>
      application域对象:a:::${Application["cc"]}<br/>
      请求参数:::::age=${RequestParameters["age"]}:::n=${RequestParameters["n"]}<br/>

body>
html>

• 测试

9.3案例2:流程控制

• action

@RequestMapping("/m2.action")
public String method02(HttpServletRequest req){
    List<Student>  list=new ArrayList<>();
    for (int i = 0; i < 18; i++) {
        float score=(int)(Math.random()*200-50);
        list.add(new Student(1000+i,"韩梅"+i,score,i%2==0?"男":"女",i%2==0));
    }
    list.add(new Student(1002,null,30f,"圣",true));
    list.add(new Student(1001,null,30f,"妖",true));
    req.setAttribute("list",list);

    Map<String,Integer> map=new HashMap<>();
    map.put("k11",(int)(Math.random()*100));
    map.put("k12",(int)(Math.random()*100));
    map.put("k13",(int)(Math.random()*100));
    map.put("k14",(int)(Math.random()*100));
    map.put("k15",(int)(Math.random()*100));
    req.setAttribute("map",map);
    //注意:属性名不能重复
    return "index02";
}

• index2.ftl

     <h1>流程控制:1 遍历集合h1>
     <table>
         <tr>
             <th>顺序th><th>学号th><th>名字th><th>分数th><th>等级th>
             <th>性别th><th>称呼th><th>政治th>
         tr>
         <#list Request["list"] as stu>
              <tr>
                  <td>${stu_index}td> 
                  <td>${stu.id}td>
                  <td>
                      <#if stu.name??> 
                           ${stu.name}
                      <#else>
                           无名
                      #if>
                  td>
                  <td>${stu.score}td>
                  <td>
                      <#if stu.score lt 0 || stu.score gt 100>
                               无效
                          <#elseif  stu.score lt 60>
                               不及格
                          <#elseif  stu.score lt 70>
                               及格
                          <#elseif  stu.score lt 80>
                               良好
                          <#else>
                               优秀
                      #if>
                  td>
                  <td>${stu.sex}td>
                  <td>
                      <#if stu.sex == "男">
                          帅哥
                          <#elseif stu.sex == "女">
                          美女
                          <#else>
                          妖精
                      #if>
                  td>
                  <td>
                      <#if stu.dy>
                           党员
                      <#else>
                           群众
                      #if>
                  td>
              tr>
         #list>
     table>
     <h1>流程控制:2 九九乘法表h1>
     <table>
         <#list 1..9 as i>
             <tr>
                 <#list 1..9 as j>
                     <td>
                         <#if j lte i>
                             ${i}*${j}=${i*j}
                         <#else>
                              
                         #if>
                     td>
                 #list>
             tr>
         #list>
     table>
     
     
     <#list list as ss>
         ${ss_index}:::${ss.id}<br/>
     #list>

     <h1>遍历maph1>
     <#list map?keys as k>
         ${k}::${map[k]}<br/>
     #list>

9.3 案例3:函数

• action

@RequestMapping("/m3.action")
public String method03(HttpServletRequest req){
    List<Student>  list=new ArrayList<>();
    for (int i = 0; i < 18; i++) {
        float score=(int)(Math.random()*200-50);
        list.add(new Student(1000+i,"韩梅"+i,score,i%2==0?"男":"女",i%2==0));
    }
    list.add(new Student(1002,null,30f,"圣",true));
    list.add(new Student(1001,null,30f,"妖",true));
    req.setAttribute("listStu",list);
    //注意:属性名不能重复
    return "index03";
}

• index03.ftl

<h1>freemarker中:正常使用:js css htmlh1>
<h1>函数的使用::日期h1>
获取当前时间.now::::${.now?datetime}<br/>
获取当前时间.now::年月日::::${.now?date}<br/>
获取当前时间.now::时分秒::::${.now?time}<br/>
获取当前时间.now::时分秒::::${.now?string("yyyy-MM-dd HH:mm:ss")}<br/>

<h1>函数的使用::集合h1>
<#assign arr1=[1,4,6,8,9,0,33,2,5,7]/>
遍历集合:::<#list arr1 as n>${n}::${n_index},#list><br/>
获取元素个数:::${arr1?size}<br/>
获取第一个元素:::${arr1?first}<br/>
获取最后一个元素:::${arr1?last}<br/>
数组反转:::::<#list arr1?reverse as n>${n},#list><br/>
数组排序:::::<#list arr1?sort as n>${n},#list><br/>
数组排序:::::<#list arr1?sort?reverse as n>${n},#list><br/>
按元素的指定属性排序:::<br/>
<#list Request["listStu"]?sortBy("score") as stu>
    ${stu}<br/>
#list>

<h1>函数的使用::字符串h1>
<#assign str="abc123456abcABCDEFG"/>
字符串长度:::${str?length}<br/>
字符串转化为大写:::${str?length}<br/>
字符串首字母大写:::${str?uncapFirst}<br/>
字符串所有字母大写:::${str?upperCase}<br/>
字符串所有字母小写:::${str?lowerCase}<br/>
字符串获取元素下标:::${str?indexOf("a")}<br/>
字符串从指定索引处找:::${str?indexOf("a",5)}<br/>
字符串去除两边空格:::${str?trim}<br/>
字符串字符替换:::${str?replace("a","-")}<br/>
字符串判断头:::${str?startsWith("abc")?c}<br/>
字符串判断尾:::${str?endsWith("abc")?c}<br/>
字符串切割:::${str?split("a")?size}<br/>

9.4 其他内容

    <h1>自己定义变量h1>
    <#assign hehe="呵呵"/>  
    <h1>空值判断h1>
    <#if hehe??>
        hehe=${hehe}
        <#else>
        hehe变量不存在
    #if>
    <h1>空值转换h1>
    ${haha!"haha没值"}<br/>
    ${hehe!"hehe没值"}<br/>
    <h1>不能直接输出booleanh1>
    <#assign ab=true/>
    ab=${ab?c}<br/>
    ab=${ab?string("对","错")}<br/>

    <h1>运算符:::比较运算符::+ - * / %h1>
    1+1=${1+1}<br/>
    3-1=${3-1}<br/>
    2*3=${2*3}<br/>
    6*2=${6*2}<br/>
    5%3=${5%3}<br/>
    <h1>运算符:::逻辑运算符::&& || !h1>
    ${(1 gt 0 && 2 lt 3)?c}<br/>
    ${(1 gt 0 || 2 lt 3)?c}<br/>
    ${(!true)?c}<br/>

    <h1>运算符:::比较运算符::gt lt gte lte == !=  h1>
    ${(1 != 2)?c}<br/>
    ${(1 == 2)?c}<br/>
    ${(1 lt 2)?c}<br/>
    ${(1 lte 2)?c}<br/>
    ${(1 gt 2)?c}<br/>
    ${(1 gte 2)?c}<br/>
    <#assign c="abc"/>
    ${(c == "abc")?c}<br/>
       
    <h1>获取项目路径：request.contextPathh1>
    <a href="${request.contextPath}/hehe">hqhqa><br/>