開發工具
下載IDEA
Idea下maven的配置和使用
IntelliJ IDEA: 無法創建Java Class文件
數據庫工具
下載mysql安裝工具,安裝到PC
下載Navicat Premium作爲可視化的數據工具
測試工具
下載postman進行測試
開始
demo的結構如圖:
StudentController.java
package com.example.controller;
import com.example.entity.Student;
import com.example.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
@RestController //控制層註解並實現返回格式爲json
@RequestMapping("/s") //配置訪問路徑
public class StudentController {
@Autowired
private StudentService studentService;
@PostMapping("/add")
public Student save(Student student){
return studentService.save(student);
}
@PostMapping("/update")
public Student update(Student student){
Student s = studentService.findStuById(student.getId());
s.setName(student.getName());
s.setAge(student.getAge());
s.setSex(student.getSex());
return studentService.save(s);
}
@GetMapping("/del/{id}")
public String del(@PathVariable int id){
studentService.delete(id);
return "yes";
}
@GetMapping("/findByName/{name}")
public List<Student> findByName(@PathVariable String name){
return studentService.findStuByName(name);
}
@GetMapping("/query")
public Page<Student> findByPage(Integer page, HttpServletResponse response){
response.setHeader("Access-Control-Allow-Origin","*");
if (page == null || page <= 0) {
page = 0;
} else {
page -= 1;
}
return studentService.findAll(page,5);
}
}
StudentDao.java
package com.example.dao;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import com.example.entity.Student;
import java.util.List;
public interface StudentDao extends JpaRepository<Student,Integer> {
//簡單的增刪改查不需要寫,這個只不過爲了辨別寫了個名,不寫也有底層的findById方法
Student findStudentById(Integer id);
//稍複雜的SQL語句需要自定義,格式如下
@Query(name = "findStuByName",nativeQuery = true,value = "select * from student where name=:name")
List<Student> findStuByName(@Param("name") String name);
}
Student.java
package com.example.entity;
import javax.persistence.*;
@Entity
@Table(name="student")
public class Student {
@Id //設置主鍵
@GeneratedValue(strategy = GenerationType.IDENTITY) //自增
private Integer id;
private String name;
private int age;
private String sex;
public Student() {
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
", sex='" + sex + '\'' +
'}';
}
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 int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
}
StudentService.java
package com.example.service;
import org.springframework.data.domain.Page;
import com.example.entity.Student;
import java.util.List;
public interface StudentService {
Student save(Student student);
void delete(Integer id);
Student findStuById(Integer id);
List<Student> findStuByName(String name);
Page<Student> findAll(int page, int pageSize);
}
StudentServiceImpl.java
package com.example.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import com.example.entity.Student;
import java.util.List;
import com.example.dao.StudentDao;
@Service //告訴springboot控制層實現類不然找不到注入
public class StudentServiceImpl implements StudentService{
@Autowired
private StudentDao studentDao;
@Override
public Student save(Student student) {
return studentDao.save(student);
}
@Override
public void delete(Integer id) {
studentDao.deleteById(id);
}
@Override
public Student findStuById(Integer id) {
return studentDao.findStudentById(id);
}
@Override
public List<Student> findStuByName(String name) {
return studentDao.findStuByName(name);
}
@Override
public Page<Student> findAll(int page, int pageSize) {
Pageable pageable= (Pageable) PageRequest.of(page,pageSize);
return studentDao.findAll(pageable);
}
}
springBoot學習筆記之application.yml配置文件
在application.properties 文件的同級目錄下新建一個 application.yml 文件,刪除了application.properties
,application.yml 文件的配置:
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/springboot?useUnicode=true&autoReconnect=true&useSSL=false&zeroDateTimeBehavior=convertToNull&serverTimezone=UTC
username: root
password: root
jpa:
show-sql: true
database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
database: mysql
hibernate:
ddl-auto: update
server:
port: 8088
注意:
1. ddl-auto: update一定要配置,要不然不能自動生成表格
2.SpringbootApplication一定和controller文件夾同級,要不然同樣不能自動生成表格
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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- druid數據庫連接池-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper-spring-boot-starter -->
<!--分頁插件-->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.10</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
如果沒有錯誤的話,就可以運行了,通過postman來測試
application.yml文件裏有port: 8088,說明端口是8080,然後嘗試訪問StudentController裏的add方法
@RestController //控制層註解並實現返回格式爲json
@RequestMapping("/s") //配置訪問路徑
public class StudentController {
@Autowired
private StudentService studentService;
@PostMapping("/add")
public Student save(Student student){
return studentService.save(student);
}
postman訪問:POST localhost:8088/s/add?name=你好&age=20&sex=男,就可以在數據庫中查看到這幾個字段
其他方法:
GET: localhost:8088/s/query
GET:localhost:8088/s/del/1
GET:localhost:8088/s/update?id=1&name=測試2&age=30&sex=女
findByName方法有個問題,如果按照這樣寫,只能接收非中文的參數,比如
GET:localhost:8088/s/findByName/112
如果要支持中文,需要寫成這樣:
@GetMapping("/findByName")
public List<Student> findByName(@RequestParam String name){
return studentService.findStuByName(name);
}
GET:localhost:8088/s/findByName?name=測試1
參考資料:
簡單springboot項目實現增刪改查加分頁