简单springboot项目实现增删改查加分页

一、创建springboot项目


二、完善目录结构

三、配置pom.xml中的依赖

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.kudesoft</groupId>
    <artifactId>kudesoft</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>kudesoft</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>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </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>
        </dependency>
        <!-- druid数据库连接池-->
        <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 -->
        <!--分页插件-->
        <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>

四、配置application.properties

#数据源配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useSSL=false&useUnicode=true&characterEncoding=utf-8&autoReconnect=true&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.initialSize=20
spring.datasource.minIdle=50
spring.datasource.maxActive=500


#上下文配置
server.port=8888
server.servlet.context-path=/kude


#配置jpa
#帮我们自动生成表结构
spring.jpa.properties.hibernate.hbm2ddl.auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql= true
spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

五、编写实体类Student

package com.kudesoft.kudesoft.entity;

import javax.persistence.*;

/**
 * @author：杜習田
 * @date 2019/5/1 17:35
 */
@Entity //告诉springboot这是实体类，有需要，来这找
@Table(name = "student") //对应数据库中的表，配合application.properties可以自动生成student表
public class Student {

    @Id //设置主键
    @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;
    }
}

六、编写student的dao接口StudentDao

package com.kudesoft.kudesoft.dao;

import com.kudesoft.kudesoft.entity.Student;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

import java.util.List;

/**
 * @author：杜習田
 * @date 2019/5/1 17:45
 */
public interface StudentDao extends JpaRepository<Student,Integer> {
    //简单的增删改查不需要写，这个只不过为了辨别写了个名，不写也有底层的findById方法
    Student findStudentById(Integer id);
    //稍复杂的SQL语句需要自定义，格式如下
    @Query(name = "findStuByName",nativeQuery = true,value = "select * from student where name=:name")
    List<Student> findStuByName(@Param("name") String name);

}

七、编写服务层接口StudentService

package com.kudesoft.kudesoft.service;

import com.kudesoft.kudesoft.entity.Student;
import org.springframework.data.domain.Page;

import java.util.List;

/**
 * @author：杜習田
 * @date 2019/5/1 17:54
 */
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);

}

八、编写服务层接口的实现类StudentServiceImpl,可以仔细的看一下，很神奇,简单的增删改查SQL语句一点都不用写

package com.kudesoft.kudesoft.service;

import com.kudesoft.kudesoft.dao.StudentDao;
import com.kudesoft.kudesoft.entity.Student;
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 java.util.List;

/**
 * @author：杜習田
 * @date 2019/5/1 17:58
 */
@Service  //告诉springboot控制层实现类不然找不到注入
public class StudentServiceImpl implements StudentService {

    @Autowired //自动注入
    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 = PageRequest.of(page,pageSize);
        return studentDao.findAll(pageable);
    }
}

九、编写控制层类StudentController实现网络访问

package com.kudesoft.kudesoft.controller;

import com.kudesoft.kudesoft.entity.Student;
import com.kudesoft.kudesoft.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.HttpServletResponse;
import java.util.List;

/**
 * @author：杜習田
 * @date 2019/5/1 18:02
 */
@RestController  //控制层注解并实现返回格式为json
@RequestMapping("/s") //配置访问路径
public class StudentController {

    @Autowired
    private StudentService studentService;

    @PostMapping("/add") //post请求
    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}") //get请求 RESTful风格
    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","*");//解决跨域请求

        if (page == null || page <= 0) {
            page = 0;
        } else {
            page -= 1;
        }
        return studentService.findAll(page, 5);
    }

}

十、运行
运行成功的样子是这样的

十一、测试
怎么测试呢？也没有web网页，这里我们需要一个专业的工具，谷歌的postman浏览器插件，但是这里需要翻墙麻烦，所以这里给大家提供pc版的postman
链接：https://pan.baidu.com/s/1P0DDDQlaR-jsPMym_5oAaw
提取码：5hg0
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这个项目源码已上传至码云
https://gitee.com/ywhc/kudesoft