springboot脚手架搭建

①首先配置java的环境，也就是下载jdk1.8

验证是否安装成功：

②下载apache maven

 ③用idea创建工程

配置如下：

 

 编码配置：

删除无用图片：

改写文件后缀：

④用postman测试接口

postman下载地址：Download Postman | Get Started for Free

 先尝试创建一个数据库：

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '名称',
  `age` int(11) NULL DEFAULT NULL COMMENT '年龄',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 3 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, '张三', 20);
INSERT INTO `user` VALUES (2, '李四', 21);

DROP TABLE IF EXISTS `book`;
CREATE TABLE `book`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `mc` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '名称',
  `price` double(10, 2) NULL DEFAULT NULL COMMENT '价格',
  `user_id` int(11) NULL DEFAULT NULL COMMENT '用户id',
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `user_id`(`user_id`) USING BTREE,
  CONSTRAINT `book_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE = InnoDB AUTO_INCREMENT = 27 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci COMMENT = '书籍表' ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of book
-- ----------------------------
INSERT INTO `book` VALUES (7, '红楼梦', 66.01, 1);
INSERT INTO `book` VALUES (8, '西游记三', 55.00, 2);
INSERT INTO `book` VALUES (9, '三国演义', 33.00, 2);
INSERT INTO `book` VALUES (10, '三国演义', 34.00, 2);
INSERT INTO `book` VALUES (11, '红楼梦', 66.01, 1);
INSERT INTO `book` VALUES (12, '西游记三', 55.00, 2);
INSERT INTO `book` VALUES (13, '三国演义', 33.00, 2);
INSERT INTO `book` VALUES (14, '三国演义', 34.00, 2);
INSERT INTO `book` VALUES (15, '红楼梦', 66.01, 1);
INSERT INTO `book` VALUES (16, '西游记三', 55.00, 2);
INSERT INTO `book` VALUES (17, '三国演义', 33.00, 2);
INSERT INTO `book` VALUES (18, '三国演义', 34.00, 2);
INSERT INTO `book` VALUES (19, '红楼梦', 66.01, 1);
INSERT INTO `book` VALUES (20, '西游记三', 55.00, 2);
INSERT INTO `book` VALUES (21, '三国演义', 33.00, 2);
INSERT INTO `book` VALUES (22, '三国演义', 34.00, 2);
INSERT INTO `book` VALUES (23, '红楼梦', 66.01, 1);
INSERT INTO `book` VALUES (24, '西游记三', 55.00, 2);
INSERT INTO `book` VALUES (25, '三国演义', 33.00, 2);
INSERT INTO `book` VALUES (26, '三国演义', 34.00, 2);

然后在application.properties文件编写如下代码：

server.port=9090//这里是设置自己想要运行的端口号
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot
//springboot是我设置在3306端口的数据库名
spring.datasource.username=root
spring.datasource.password=123456

然后创建如下图文件：

 WebController：

package com.example.springboot.controller;

import com.example.springboot.entity.Book;
import com.example.springboot.mapper.BookMapper;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

@RestController
public class WebController {
    @Resource
    BookMapper bookMapper;

    @RequestMapping("/")  //   / 是可以省略的
    public String hello1233() {
        return "你好啊";
    }
    @RequestMapping(value = "/user" , method = RequestMethod.POST)
    public void insertBook(@RequestBody Book book){
        bookMapper.insert(book);
    }

    @RequestMapping(value = "/user", method = RequestMethod.PUT)
    public void updateBook(@RequestBody Book book) {
        bookMapper.updateById(book);
    }

    @RequestMapping(value = "/user", method = RequestMethod.GET)
    public List listBook() {
        return bookMapper.listBook();
    }
}

 Book：

package com.example.springboot.entity;

public class Book {
    private Integer id;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getMc() {
        return mc;
    }

    public void setMc(String mc) {
        this.mc = mc;
    }

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    public Integer getUser_id() {
        return user_id;
    }

    public void setUser_id(Integer user_id) {
        this.user_id = user_id;
    }

    private String mc;
    private Double price;
    private Integer user_id;
}

BookMapper：

package com.example.springboot.mapper;

import com.example.springboot.entity.Book;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import java.util.List;

@Mapper
public interface BookMapper {
    @Insert("INSERT INTO book (mc, price, user_id) VALUES(#{mc}, #{price}, #{user_id})")
    void insert(Book book);

    @Update("UPDATE book SET mc = #{mc} , price = #{price} , user_id=#{user_id} where id=#{id}")
    void updateById(Book book);

    @Select("select * from book order by id desc ")
    List listBook();
}

运行项目：

 

 增加数据：

修改数据：

 

 

获取数据：