SpringBoot HelloWorld 之 实现注册功能

一.配置

创建数据库big_event

CREATE TABLE `user` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'ID',
  `username` varchar(20) COLLATE utf8_unicode_ci NOT NULL COMMENT '用户名',
  `password` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '密码',
  `nickname` varchar(10) COLLATE utf8_unicode_ci DEFAULT '' COMMENT '昵称',
  `email` varchar(128) COLLATE utf8_unicode_ci DEFAULT '' COMMENT '邮箱',
  `user_pic` varchar(128) COLLATE utf8_unicode_ci DEFAULT '' COMMENT '头像',
  `create_time` datetime NOT NULL COMMENT '创建时间',
  `update_time` datetime NOT NULL COMMENT '修改时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `username` (`username`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='用户表'

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>
    <groupId>com.javalearn</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>demo</description>
    <properties>
        <java.version>17</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>3.0.2</spring-boot.version>
    </properties>
    <dependencies>
        <!-- MySQL Driver -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
<!--&lt;!&ndash;        persistence&ndash;&gt;-->
<!--        <dependency>-->
<!--            <groupId>javax.persistence</groupId>-->
<!--            <artifactId>persistence-api</artifactId>-->
<!--            <version>1.0</version>-->
<!--        </dependency>-->
<!--jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!-- Spring Boot Starter Data JPA -->
        <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>

<!--        mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>3.0.0</version>
        </dependency>
<!--        -->
<!--        -->
<!--        -->
        <!--mybatis依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>3.0.0</version>
        </dependency>

        <!--mysql驱动依赖-->
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
        </dependency>

        <!--lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <!--validation依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

        <!--java-jwt坐标-->
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>4.4.0</version>
        </dependency>

        <!--单元测试的坐标-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>

        <!--pageHelper坐标-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.4.6</version>
        </dependency>

        <!--阿里云oss依赖坐标-->
        <dependency>
            <groupId>com.aliyun.oss</groupId>
            <artifactId>aliyun-sdk-oss</artifactId>
            <version>3.15.1</version>
        </dependency>
<!--        -->
<!--        -->
<!--        -->

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>17</source>
                    <target>17</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
                <configuration>
                    <mainClass>com.javalearn.demo.DemoApplication</mainClass>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

src/main/resources/application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/big_event
    username: root
    password: root
server:
  port: 8080

mybatis:
  configuration:
    map-underscore-to-camel-case: true #开启驼峰命名和下划线命名的自动转换
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

二.controller控制层

src/main/java/com/javalearn/demo/controller/UserController.java

package com.javalearn.demo.controller;

import com.javalearn.demo.pojo.Result;
import com.javalearn.demo.pojo.User;
import com.javalearn.demo.service.UserService;
import org.springframework.web.bind.annotation.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @PostMapping("/register")
    public Result register(String username, String password) {
        // 查询用户
        User u = userService.findByUsername(username);
        if (u == null) {
            // 没有占用
            // 注册
            userService.register(username, password);
            return Result.success();
        } else {
            return Result.error("用户名已占用");
        }
    }

}

三.service业务层

src/main/java/com/javalearn/demo/service/UserService.java

package com.javalearn.demo.service;

import com.javalearn.demo.pojo.User;
import java.util.List;

public interface UserService {
    // 根据用户名查询
    User findByUsername(String username);
    // 注册
    void register(String username, String password);

}

src/main/java/com/javalearn/demo/service/impl/UserServiceImpl.java

package com.javalearn.demo.service.impl;

import com.javalearn.demo.pojo.User;
import com.javalearn.demo.mapper.UserMapper;
import com.javalearn.demo.service.UserService;
import com.javalearn.demo.utils.Md5Util;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public User findByUsername(String username) {
        User u = userMapper.findByUsername(username);
        return u;
    }

    @Override
    public void register(String username, String password){
        // 加密
        String md5String = Md5Util.getMD5String(password);
        // 添加
        userMapper.add(username, md5String);
    }
}

四.mapper（Dao）持久层

src/main/java/com/javalearn/demo/mapper/UserMapper.java

package com.javalearn.demo.mapper;

import com.javalearn.demo.pojo.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;


@Mapper
public interface UserMapper {
    // 根据用户名查询用户
    @Select("select * from user where username = #{username}")
    User findByUsername(String username);

    // 添加
    @Insert("insert into user(username, password, create_time, update_time)" +
            " values(#{username}, #{password},now(),now())")
    void add(@Param("username") String uasername, @Param("password") String password);
}

五.pojo（简单java对象）

src/main/java/com/javalearn/demo/pojo/Result.java

package com.javalearn.demo.pojo;



import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

//统一响应结果
@NoArgsConstructor
@AllArgsConstructor
@Data
public class Result<T> {
    private Integer code;//业务状态码  0-成功  1-失败
    private String message;//提示信息
    private T data;//响应数据

    //快速返回操作成功响应结果(带响应数据)
    public static <E> Result<E> success(E data) {
        return new Result<>(0, "操作成功", data);
    }

    //快速返回操作成功响应结果
    public static Result success() {
        return new Result(0, "操作成功", null);
    }

    public static Result error(String message) {
        return new Result(1, message, null);
    }
}

src/main/java/com/javalearn/demo/pojo/User.java

package com.javalearn.demo.pojo;

import lombok.Data;
import java.time.LocalDateTime;

@Data
public class User {
    private Integer id;//主键ID
    private String username;
    private String password;
    private String nickname;//昵称
    private String email;
    private String userPic;//用户头像地址
    private String createTime;
    private String updateTime;
}

六.utils（工具）

src/main/java/com/javalearn/demo/utils/Md5Util.java

package com.javalearn.demo.utils;


import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Md5Util {
    /**
     * 默认的密码字符串组合，用来将字节转换成 16 进制表示的字符,apache校验下载的文件的正确性用的就是默认的这个组合
     */
    protected static char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    protected static MessageDigest messagedigest = null;

    static {
        try {
            messagedigest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException nsaex) {
            System.err.println(Md5Util.class.getName() + "初始化失败，MessageDigest不支持MD5Util。");
            nsaex.printStackTrace();
        }
    }

    /**
     * 生成字符串的md5校验值
     *
     * @param s
     * @return
     */
    public static String getMD5String(String s) {
        return getMD5String(s.getBytes());
    }

    /**
     * 判断字符串的md5校验码是否与一个已知的md5码相匹配
     *
     * @param password  要校验的字符串
     * @param md5PwdStr 已知的md5校验码
     * @return
     */
    public static boolean checkPassword(String password, String md5PwdStr) {
        String s = getMD5String(password);
        return s.equals(md5PwdStr);
    }


    public static String getMD5String(byte[] bytes) {
        messagedigest.update(bytes);
        return bufferToHex(messagedigest.digest());
    }

    private static String bufferToHex(byte bytes[]) {
        return bufferToHex(bytes, 0, bytes.length);
    }

    private static String bufferToHex(byte bytes[], int m, int n) {
        StringBuffer stringbuffer = new StringBuffer(2 * n);
        int k = m + n;
        for (int l = m; l < k; l++) {
            appendHexPair(bytes[l], stringbuffer);
        }
        return stringbuffer.toString();
    }

    private static void appendHexPair(byte bt, StringBuffer stringbuffer) {
        char c0 = hexDigits[(bt & 0xf0) >> 4];// 取字节中高 4 位的数字转换, >>>
        // 为逻辑右移，将符号位一起右移,此处未发现两种符号有何不同
        char c1 = hexDigits[bt & 0xf];// 取字节中低 4 位的数字转换
        stringbuffer.append(c0);
        stringbuffer.append(c1);
    }

}