SpringBoot学习笔记

Spring Boot

Spring Boot 是一个快速开发框架,可以迅速搭建出一套基于 Spring 框架体系的应用,是 Spring Cloud 的基础。

Spring Boot 开启了各种自动装配,从而简化代码的开发,不需要编写各种配置文件,只需要引入相关依赖就可以迅速搭建一个应用。

  • 特点

1、不需要 web.xml

2、不需要 springmvc.xml

3、不需要 tomcat,Spring Boot 内嵌了 tomcat

4、不需要配置 JSON 解析,支持 REST 架构

5、个性化配置非常简单

  • 如何使用

1、创建 Maven 工程,导入相关依赖。

<!-- 继承父包 -->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.7.RELEASE</version>
</parent>

<dependencies>
  <!-- web启动jar -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
  </dependency>
</dependencies>

2、创建 Student 实体类

package com.janeroad.entity;

import lombok.Data;

@Data
public class Student {
private long id;
private String name;
private int age;
}

3、StudentRepository

package com.janeroad.repository;

import com.janeroad.entity.Student;

import java.util.Collection;

public interface StudentRepository {
    public Collection<Student> findAll();
    public Student findById(long id);
    public void saveOrUpdate(Student student);
    public void deleteById(long id);
}

4、StudentRepositoryImpl

package com.janeroad.repository.impl;

import com.janeroad.entity.Student;
import com.janeroad.repository.StudentRepository;
import org.springframework.stereotype.Repository;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
@Repository
public class StudentRepositoryImpl implements StudentRepository {
private static Map<Long,Student> studentMap;
static {
    studentMap = new HashMap<>();
    studentMap.put(1L,new Student(1L,"张三",22));
    studentMap.put(2L,new Student(2L,"李四",23));
    studentMap.put(3L,new Student(3L,"王五",24));
}

    @Override
    public Collection<Student> findAll() {
        return studentMap.values();
    }

    @Override
    public Student findById(long id) {
        return studentMap.get(id);
    }

    @Override
    public void saveOrUpdate(Student student) {
        studentMap.put(student.getId(),student);
    }

    @Override
    public void deleteById(long id) {
        studentMap.remove(id);
    }
}

5、StudentHandler

package com.janeroad.controller;

import com.janeroad.entity.Student;
import com.janeroad.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@RestController
@RequestMapping("/student")
public class StudentHandler {
    @Autowired
    private StudentRepository studentRepository;
    @GetMapping("/findAll")
    public Collection<Student> findAll(){
        return studentRepository.findAll() ;
    }
    @GetMapping("/findById/{id}")
    public  Student findById(@PathVariable("id") long id){
        return studentRepository.findById(id);
    }
    @PostMapping("/save")
    public void save(@RequestBody Student student){
        studentRepository.saveOrUpdate(student);
    }
    @PutMapping("/update")
    public void update(@RequestBody Student student){
        studentRepository.saveOrUpdate(student);
    }
    @DeleteMapping("/deleteById/{id}")
    public void deleteById(@PathVariable("id") long id){
        studentRepository.deleteById(id);
    }
}

6、application.yml

server:
  port: 9090

7、启动类

package com.janeroad;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

@SpringBootApplication 表示当前类是 Spring Boot 的入口,Application 类的存放位置必须是其他相关业务类的存放位置的父级。

Spring Boot 整合 JSP

  • pom.xml
<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.0.7.RELEASE</version>
</parent>

<dependencies>
  <!-- web -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>

  <!-- 整合JSP -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
  </dependency>
  <dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
  </dependency>

  <!-- JSTL -->
  <dependency>
    <groupId>jstl</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
  </dependency>

  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
  </dependency>
</dependencies>
  • 创建配置文件 application.yml
server:
  port: 8181
spring:
  mvc:
    view:
      prefix: /
      suffix: .jsp
  • 创建 Handler
package com.janeroad.controller;

import com.janeroad.entity.Student;
import com.janeroad.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("/hello")
public class HelloHandler {
    @Autowired
    private StudentRepository studentRepository;
    @GetMapping("/index")
    public ModelAndView index(){
      ModelAndView modelAndView=new ModelAndView();
      modelAndView.setViewName("index");
      modelAndView.addObject("list",studentRepository.findAll());
      return modelAndView;
    }
    @GetMapping("/deleteById/{id}")
    public String deleteById(@PathVariable("id") long id){
        studentRepository.deleteById(id);
        return "redirect:/hello/index";
    }
    @PostMapping("/save")
    public String save(Student student){
        studentRepository.saveOrUpdate(student);
        return "redirect:/hello/index";
    }
    @PostMapping("/update")
    public String update(Student student){
        studentRepository.saveOrUpdate(student);
        return "redirect:/hello/index";
    }
    @GetMapping("/findById/{id}")
    public ModelAndView findById(@PathVariable("id") long id){
        ModelAndView modelAndView=new ModelAndView();
        modelAndView.setViewName("update");
        modelAndView.addObject("student",studentRepository.findById(id));
        return modelAndView;
    }
}
  • JSP

index.jsp

<%--
  Created by IntelliJ IDEA.
  User: JaneRoad
  Date: 2020/3/14
  Time: 13:50
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>学生系统</title>
</head>
<body>
<h1>学生信息</h1>
<table>
    <tr>
        <th>学生编号</th>
        <th>学生姓名</th>
        <th>学生年龄</th>
        <th>操作</th>
    </tr>
    <c:forEach items="${list}" var="student">
        <tr>
            <td>${student.id}</td>
            <td>${student.name}</td>
            <td>${student.age}</td>
            <td>
                <a href="/hello/findById/${student.id}">修改</a>
                <a href="/hello/deleteById/${student.id}">删除</a>
            </td>
        </tr>
    </c:forEach>
</table>
<a href="/save.jsp">添加学生</a>
</body>
</html>

save.jsp(添加操作)

<%--
  Created by IntelliJ IDEA.
  User: JaneRoad
  Date: 2020/3/14
  Time: 14:29
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加</title>
</head>
<body>
<form action="/hello/save" method="post">
    ID:<input type="text" name="id"/><br/>
    name:<input type="text" name="name"/><br/>
    age:<input type="text" name="age"/><br/>
    <input type="submit" value="提交"/>
</form>
</body>
</html>

update.jsp(修改操作)

<%--
  Created by IntelliJ IDEA.
  User: JaneRoad
  Date: 2020/3/14
  Time: 14:31
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>修改</title>
</head>
<body>
<form action="/hello/update" method="post">
    ID:<input type="text" name="id" value="${student.id}" readonly/><br/>
    name:<input type="text" name="name" value="${student.name}"/><br/>
    age:<input type="text" name="age" value="${student.age}" /><br/>
    <input type="submit" value="提交"/>
</form>
</body>
</html>

Spring Boot HTML

Spring Boot 可以结合 Thymeleaf 模版来整合 HTML,使用原生的 HTML 作为视图。

Thymeleaf 模版是面向 Web 和独立环境的 Java 模版引擎,能够处理 HTML、XML、JavaScript、CSS 等。

<p th:text="${message}"></p>
  • pom.xml
<!-- 继承父包 -->
<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.0.7.RELEASE</version>
</parent>

<dependencies>
  <!-- web启动jar -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>

  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
  </dependency>

  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
  </dependency>
</dependencies>
  • appliction.yml
server:
  port: 9090
spring:
  thymeleaf:
    prefix: classpath:/templates/
    suffix: .html
    mode: HTML5
    encoding: UTF-8
  • Handler
package com.janeroad.controller;

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


@Controller
@RequestMapping("/index")
public class IndexHandler {
    @GetMapping("/index")
    public String index(){
        System.out.println("index...");
        return "index";
    }
}
  • HTML
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Hello World</title>
</head>
<body>
    <h1>Hello World</h1>
</body>
</html>

如果希望客户端可以直接访问 HTML 资源,将这些资源放置在 static 路径下即可,否则必须通过 Handler 的后台映射才可以访问静态资源。

Thymeleaf 常用语法

  • 赋值、拼接
@GetMapping("/index2")
public String index2(Map<String,String> map){
  map.put("name","张三");
  return "index";
}
<p th:text="${name}"></p>
<p th:text="'学生姓名是'+${name}+2"></p>
<p th:text="|学生姓名是,${name}|"></p>
  • 条件判断:if/unless

th:if 表示条件成立时显示内容,th:unless 表示条件不成立时显示内容

@GetMapping("/if")
public String index3(Map<String,Boolean> map){
    map.put("flag",true);
    return "index";
}
<p th:if="${flag == true}" th:text="if判断成立"></p>
<p th:unless="${flag != true}" th:text="unless判断成立"></p>
  • 循环
@GetMapping("/index")
public String index(Model model){
    System.out.println("index...");
    List<Student> list = new ArrayList<>();
    list.add(new Student(1L,"张三",22));
    list.add(new Student(2L,"李四",23));
    list.add(new Student(3L,"王五",24));
    model.addAttribute("list",list);
    return "index";
}
<table>
  <tr>
    <th>index</th>
    <th>count</th>
    <th>学生ID</th>
    <th>学生姓名</th>
    <th>学生年龄</th>
  </tr>
  <tr th:each="student,stat:${list}" th:style="'background-color:'+@{${stat.odd}?'#F2F2F2'}">
    <td th:text="${stat.index}"></td>
    <td th:text="${stat.count}"></td>
    <td th:text="${student.id}"></td>
    <td th:text="${student.name}"></td>
    <td th:text="${student.age}"></td>
  </tr>
</table>

stat 是状态变量,属性:

  • index 集合中元素的index(从0开始)

  • count 集合中元素的count(从1开始)

  • size 集合的大小

  • current 当前迭代变量

  • even/odd 当前迭代是否为偶数/奇数(从0开始计算)

  • first 当前迭代的元素是否是第一个

  • last 当前迭代的元素是否是最后一个

  • URL

Thymeleaf 对于 URL 的处理是通过 @{...} 进行处理,结合 th:href 、th:src

@GetMapping("/img")
public String img(Model model){
    model.addAttribute("src","https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1584293836681&di=e54530c8c4d213c6a08a74695bc5b8f1&imgtype=0&src=http%3A%2F%2Ftc.sinaimg.cn%2Fmaxwidth.800%2Ftc.service.weibo.com%2Fmmbiz_qpic_cn%2F33192185666f3c91d5f7065eab5bc87f.jpg");
    return "index";
}
<h1>Hello World</h1>
<a th:href="@{http://www.baidu.com}">跳转</a>
<a th:href="@{http://localhost:9090/index/url/{na}(na=${name})}">跳转2</a>
<img th:src="${src}">
<div th:style="'background:url('+ @{${src}} +');'">
<br/>
<br/>
<br/>
</div>
  • 三元运算
@GetMapping("/eq")
public String eq(Model model){
    model.addAttribute("age",30);
    return "index";
}
<input th:value="${age gt 30?'中年':'青年'}"/>
  • gt great than 大于

  • ge great equal 大于等于

  • eq equal 等于

  • lt less than 小于

  • le less equal 小于等于

  • ne not equal 不等于

  • switch

@GetMapping("/switch")
public String switchTest(Model model){
    model.addAttribute("gender","女");
    return "index";
}
<div th:switch="${gender}">
  <p th:case="女">女</p>
  <p th:case="男">男</p>
  <p th:case="*">未知</p>
</div>
  • 基本对象
    • #ctx :上下文对象
    • #vars:上下文变量
    • #locale:区域对象
    • #request:HttpServletRequest 对象
    • #response:HttpServletResponse 对象
    • #session:HttpSession 对象
    • #servletContext:ServletContext 对象
@GetMapping("/object")
public String object(HttpServletRequest request){
    request.setAttribute("request","request对象");
    request.getSession().setAttribute("session","session对象");
    return "index";
}
<p th:text="${#request.getAttribute('request')}"></p>
<p th:text="${#session.getAttribute('session')}"></p>
<p th:text="${#locale.country}"></p>
  • 内嵌对象

可以直接通过 # 访问。

1、dates:java.util.Date 的功能方法

2、calendars:java.util.Calendar 的功能方法

3、numbers:格式化数字

4、strings:java.lang.String 的功能方法

5、objects:Object 的功能方法

6、bools:对布尔求值的方法

7、arrays:操作数组的功能方法

8、lists:操作集合的功能方法

9、sets:操作集合的功能方法

10、maps:操作集合的功能方法

@GetMapping("/util")
public String util(Model model){
    model.addAttribute("name","zhangsan");
    model.addAttribute("users",new ArrayList<>());
    model.addAttribute("count",22);
    model.addAttribute("date",new Date());
    return "index";
}
<!-- 格式化时间 -->
<p th:text="${#dates.format(date,'yyyy-MM-dd HH:mm:sss')}"></p>
<!-- 创建当前时间,精确到天 -->
<p th:text="${#dates.createToday()}"></p>
<!-- 创建当前时间,精确到秒 -->
<p th:text="${#dates.createNow()}"></p>
<!-- 判断是否为空 -->
<p th:text="${#strings.isEmpty(name)}"></p>
<!-- 判断List是否为空 -->
<p th:text="${#lists.isEmpty(users)}"></p>
<!-- 输出字符串长度 -->
<p th:text="${#strings.length(name)}"></p>
<!-- 拼接字符串 -->
<p th:text="${#strings.concat(name,name,name)}"></p>
<!-- 创建自定义字符串 -->
<p th:text="${#strings.randomAlphanumeric(count)}"></p>

Spring Boot 数据校验

package com.janeroad.entity;

import lombok.Data;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;

@Data
public class User {
    @NotNull(message = "id不能为空")
    private Long id;
    @NotEmpty(message = "姓名不能为空")
    @Length(min=2,message = "姓名长度不能小于两位")
    private String name;
    @Min(value=16,message = "年龄必须大于16")
    private int age;
}
@GetMapping("/validator")
    public void validatorUser(@Valid User user, BindingResult bindingResult) {
    System.out.println(user);
    if (bindingResult.hasErrors()) {
    List<ObjectError> list=bindingResult.getAllErrors();
    for(ObjectError objectError:list){
        System.out.println(objectError.getCode()+"-"+objectError.getDefaultMessage());
    }
    }
}

Spring Boot 整合 JDBC

  • pom.xml
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.11</version>
</dependency>
  • application.yml
server:
  port: 9090
spring:
  thymeleaf:
    prefix: classpath:/templates/
    suffix: .html
    mode: HTML5
    encoding: UTF-8
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
  • User
package com.janeroad.entity;

import lombok.Data;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;

@Data
public class User {
    @NotNull(message = "id不能为空")
    private Long id;
    @NotEmpty(message = "姓名不能为空")
    @Length(min=2,message = "姓名长度不能小于两位")
    private String name;
    @Min(value=60,message = "成绩必须大于60")
    private double score;
}
  • UserRepository
package com.janeroad.repository;
import com.janeroad.entity.User;
import java.util.List;
public interface UserRepository {
    public List<User> findAll();
    public User findById(long id);
    public void save(User user);
    public void update(User user);
    public void deleteById(long id);
}
  • UserRepositoryImpl
package com.janeroad.repository.impl;


import com.janeroad.entity.User;
import com.janeroad.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
public class UserRepositoryImpl implements UserRepository {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public List<User> findAll() {
        return jdbcTemplate.query("select * from user",new BeanPropertyRowMapper<>(User.class));
    }

    @Override
    public User findById(long id) {
        return jdbcTemplate.queryForObject("select * from user where id = ?",new Object[]{id},new BeanPropertyRowMapper<>(User.class));
    }

    @Override
    public void save(User user) {
        jdbcTemplate.update("insert into user(name,score) values(?,?)",user.getName(),user.getScore());
    }

    @Override
    public void update(User user) {
        jdbcTemplate.update("update user set name = ?,score = ? where id = ?",user.getName(),user.getScore(),user.getId());
    }

    @Override
    public void deleteById(long id) {
        jdbcTemplate.update("delete from user where id = ?",id);
    }
}
  • Handler
package com.janeroad.controller;

import com.janeroad.entity.User;
import com.janeroad.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserHandler {
    @Autowired
    private UserRepository userRepository;

    @GetMapping("/findAll")
    public List<User> findAll(){
        return userRepository.findAll();
    }
    @GetMapping("/findById/{id}")
    public User findById(@PathVariable("id") long id){
        return userRepository.findById(id);
    }

    @PostMapping("/save")
    public void save(@RequestBody User user){
        userRepository.save(user);
    }

    @PutMapping("/update")
    public void update(@RequestBody User user){
        userRepository.update(user);
    }

    @DeleteMapping("/deleteById/{id}")
    public void deleteById(@PathVariable("id") long id){
        userRepository.deleteById(id);
    }
}

Spring Boot 整合 MyBatis

  • pom.xml
<?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>com.janeroad</groupId>
    <artifactId>springbootmybatis</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <artifactId>spring-boot-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.1.5.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
</project>
  • 创建数据表
create table student(
    id int primary key auto_increment,
    name varchar(11),
    score double,
    birthday date
);
  • 创建实体类
package com.janeroad.entity;

import lombok.Data;

import java.util.Date;

@Data
public class Student {
    private Long id;
    private String name;
    private Double score;
    private Date birthday;
}
  • 创建StudentRepository接口
package com.janeroad.repository;

import com.janeroad.entity.Student;

import java.util.List;

public interface StudentRepository {
    public List<Student> findAll();
    public Student findById(long id);
    public void save(Student student);
    public void update(Student student);
    public void deleteById(Long id);
}
  • 在resources/mapping路径下创建StudentRepository接口对应的Mapper.xml
<?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="com.janeroad.repository.StudentRepository">
    <select id="findAll" resultType="Student">
        select * from student 
    </select>

    <select id="findById" parameterType="java.lang.Long" resultType="Student">
        select * from student where id =#{id}
    </select>

    <insert id="save" parameterType="Student">
        insert into student(name,score,birthday) values(#{name},#{score},#{birthday})
    </insert>

    <update id="update" parameterType="Student">
        update student set name=#{name},score=#{score},birthday=#{birthday} where id=#{id}
    </update>

    <delete id="deleteById" parameterType="java.lang.Long">
        delete from student where id=#{id}
    </delete>

</mapper>
  • 创建StudentHandle,注入StudentRepository
package com.janeroad.controller;


import com.janeroad.entity.Student;
import com.janeroad.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class StudentHandler {
    @Autowired
    private StudentRepository studentRepository;

    @GetMapping("/findAll")
    public List<Student> findAll(){
        return studentRepository.findAll();
    }
    @GetMapping("/findById/{id}")
    public Student findById(@PathVariable("id") Long id){
        return studentRepository.findById(id);
    }

    @PostMapping("/save")
    public void save(@RequestBody Student student){
        studentRepository.save(student);
    }

    @PutMapping("/update")
    public void update(@RequestBody Student student){
        studentRepository.update(student);
    }

    @DeleteMapping("/deleteById/{id}")
    public void deleteById(@PathVariable("id") Long id){
        studentRepository.deleteById(id);
    }
}
  • resource中加入yml
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
  mapper-locations: classpath:/mapping/*.xml
  type-aliases-package: com.janeroad.entity
  • 创建Application
package com.janeroad;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.SpringApplication;
@SpringBootApplication
@MapperScan("com.janeroad.repository")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

Spring Boot 整合Spring Data JPA

JPA Hibernate 框架就是一个JPA的实现

Spring Data JPA不是对JPA规范的具体实现,本身是一个抽象层

  • pom.xml
<?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>com.janeroad</groupId>
    <artifactId>springbootmybatis</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <artifactId>spring-boot-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.1.5.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>


        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

    </dependencies>
</project>
  • Student实体类
package com.janeroad.entity;

import lombok.Data;

import javax.persistence.*;
import java.util.Date;

@Data
@Entity
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column
    private String name;
    @Column
    private Double score;
    @Column
    private Date birthday;
}
  • 创建StudentRepository接口
package com.janeroad.repository;


import com.janeroad.entity.Student;
import org.springframework.data.jpa.repository.JpaRepository;

public interface StudentRepository extends JpaRepository<Student,Long> {

}
  • 创建StudentHandler,注入StudentRepository
package com.janeroad.entity;

import com.janeroad.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;
@RestController
public class StudentHandler {
    @Autowired
    private StudentRepository studentRepository;

    @GetMapping("/findAll")
    public List<Student> findAll(){
        return studentRepository.findAll();
    }
    @GetMapping("/findById/{id}")
    public Student findById(@PathVariable("id") Long id){
        return studentRepository.getById(id);
    }
    @PostMapping("/save")
    public Student save(@RequestBody Student student){
        return studentRepository.save(student);
    }
    @PutMapping("/update")
    public Student update(@RequestBody Student student){
        return studentRepository.save(student);

    }
    @DeleteMapping("/deleteById/{id}")
    public void deleteById(@PathVariable("id") Long id){
        studentRepository.deleteById(id);
    }
}
  • application.yml
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8
    name: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    show-sql: true
    properties:
      hibernate:
        format_sql: true
  • 创建启动类
package com.janeroad;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.SpringApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

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