SpringBoot 2 -SpringBoot入门

r囧r小猫 2023-10-14 15:40 39阅读 0赞

#### SpringBoot 2 -SpringBoot入门 ####

*   *  1.简介
     *  2.第一个SpringBoot程序
     *  3.升级
     *  4.响应封装类配置

### 1.简介 ###

springboot是什么

Spring Boot它本身并不提供Spring框架的核心特性以及扩展功能，只是用于快速、敏捷地开发新一代基于Spring框架的应用程序。
    也就是说，它并不是用来替代Spring的解决方案，而是和Spring框架紧密结合用于提升Spring开发者体验的工具
    
    同时它集成了大量常用的第三方库配置（例如Jackson, JDBC, Mongo, Redis, Mail等等），
    Spring Boot应用中这些第三方库几乎可以零配置的开箱即用（out-of-the-box），大部分的Spring Boot应用都
    只需要非常少量的配置代码，开发者能够更加专注于业务逻辑

注1：敏捷式开发

注2：spring boot其实不是什么新的框架，它默认配置了很多框架的使用方式，  
就像maven整合了所有的jar包，spring boot整合了所有的框架

注3：基于Spring框架的一站式解决方案

### 2.第一个SpringBoot程序 ###

![image-20230807222029193][]

![image-20230807222726691][]

![image-20230807223609802][]

排除，配置默认不加载数据源

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
    public class Testspringboot02Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Testspringboot02Application.class, args);
        }
    
    }

再次运行

![image-20230807224628773][]

这样我们第一个程序做好了

安装 Convert YAML and Properties File 的插件

application.properties

# 应用名称
    spring.application.name=testspringboot02
    # 应用服务 WEB 访问端口
    server.port=8081
    #下面这些内容是为了让MyBatis映射
    #指定Mybatis的Mapper文件
    mybatis.mapper-locations=classpath:mappers/*xml
    #指定Mybatis的实体目录
    mybatis.type-aliases-package=com.zking.testspringboot02.mybatis.entity

选中application.properties右键点击 Convert YAML and Properties File

application.yml

mybatis:
        mapper-locations: classpath:mappers/*xml
        type-aliases-package: com.zking.testspringboot02.mybatis.entity
    server:
        port: 8081
    spring:
        application:
            name: testspringboot02

![image-20230807225632410][]

变成

![image-20230807225648536][]

### 3.升级 ###

在Controller文件夹中新建一个DemoCOntroller.java

package com.hyx.springboot01.controller;
    
    import com.hyx.springboot01.entity.Demo;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.Arrays;
    import java.util.HashMap;
    import java.util.Map;
    
    @RestController
    @RequestMapping("/demo")
    public class DemoController {
        
        @RequestMapping("/list")
        public Map list(){
        
            Map map = new HashMap();
            map.put("data", Arrays.asList(
                    new Demo(1,"足球"),
                    new Demo(2,"篮球"),
                    new Demo(3,"排球"),
                    new Demo(4,"羽毛球"),
                    new Demo(5,"台球")
            ));
            map.put("total",168);
            map.put("msg","查询成功");
            map.put("code",200);
            return map;
        }
    
        @RequestMapping("/add")
        public Map add(){
        
            Map map = new HashMap();
            map.put("msg","新增成功");
            map.put("code",200);
            return map;
        }
    
        @RequestMapping("/load")
        public Map load(){
        
            Map map = new HashMap();
            map.put("msg","加载成功");
            map.put("data",new Demo(3,"排球"));
            map.put("code",200);
            return map;
        }
    
    
        @RequestMapping("/edit")
        public Map edit(){
        
            Map map = new HashMap();
            map.put("msg","修改成功");
            map.put("code",200);
            return map;
        }
    
        @RequestMapping("/delete")
        public Map delete(){
        
            Map map = new HashMap();
            map.put("msg","删除成功");
            map.put("code",200);
            return map;
        }
    
    
    }

新建一个实体类

package com.hyx.springboot01.entity;
    
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    import lombok.ToString;
    
    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    @ToString
    public class Demo {
        
        private int id;
        private String name;
    }

![image-20230807230811114][]

运行，随便测试一下接口

![image-20230807230259950][]

### 4.响应封装类配置 ###

新建一个Result包

新建三个java类

![image-20230807233144695][]

package com.hyx.springboot01.result;
    
    public class Result<T> {
        
    
        private int code;
        private String msg;
        //因为返回的数据不知道是什么类型，所以定义一个泛型
        private T data;
        private long total;
    
        public long getTotal() {
        
            return total;
        }
    
        public void setTotal(long total) {
        
            this.total = total;
        }
    
        /**
         * 成功的时候调用
         */
        public static <T> Result<T> ok(T data) {
        
            return new Result<T>(data);
        }
        public static <T> Result<T> ok(int code,String msg) {
        
            return new Result<>(code,msg);
        }
        public static <T> Result<T> ok(int code,String msg,T data) {
        
            Result<T> success = ok(data);
            success.setCode(code);
            success.setMsg(msg);
            return success;
        }
        public static <T> Result<T> ok(int code,String msg,T data,long total) {
        
            Result<T> success = ok(code,msg,data);
            success.setTotal(total);
            return success;
        }
    
        /**
         * 失败的时候调用
         */
        public static <T> Result<T> error(CodeMsg codeMsg) {
        
            return new Result<T>(codeMsg);
        }
    
        private Result(T data) {
        
            this.data = data;
        }
    
        private Result(int code, String msg) {
        
            this.code = code;
            this.msg = msg;
        }
    
        private Result(CodeMsg codeMsg) {
        
            if (codeMsg != null) {
        
                this.code = codeMsg.getCode();
                this.msg = codeMsg.getMsg();
            }
        }
    
        public int getCode() {
        
            return code;
        }
    
        public void setCode(int code) {
        
            this.code = code;
        }
    
        public String getMsg() {
        
            return msg;
        }
    
        public void setMsg(String msg) {
        
            this.msg = msg;
        }
    
        public T getData() {
        
            return data;
        }
    
        public void setData(T data) {
        
            this.data = data;
        }
    }

package com.hyx.springboot01.result;
    
    public class CodeMsg {
        
    
        private int code;
        private String msg;
    
        //通用的错误码
        public static CodeMsg SUCCESS = new CodeMsg(200, "success");
        public static CodeMsg SERVER_ERROR = new CodeMsg(500, "服务端异常");
        public static CodeMsg BIND_ERROR = new CodeMsg(500101, "参数校验异常：%s");
        public static CodeMsg REQUEST_ILLEGAL = new CodeMsg(500102, "请求非法");
        public static CodeMsg ACCESS_LIMIT_REACHED = new CodeMsg(500104, "访问太频繁！");
        //登录模块5002XX
        public static CodeMsg SESSION_ERROR = new CodeMsg(500210, "Session不存在或者已经失效");
        public static CodeMsg PASSWORD_EMPTY = new CodeMsg(500211, "登录密码不能为空");
        public static CodeMsg MOBILE_EMPTY = new CodeMsg(500212, "手机号不能为空");
        public static CodeMsg MOBILE_ERROR = new CodeMsg(500213, "手机号格式错误");
        public static CodeMsg MOBILE_NOT_EXIST = new CodeMsg(500214, "手机号不存在");
        public static CodeMsg PASSWORD_ERROR = new CodeMsg(500215, "密码错误");
    
        //商品模块5003XX
    
        //订单模块5004XX
        public static CodeMsg ORDER_NOT_EXIST = new CodeMsg(500400, "订单不存在");
    
        //秒杀模块5005XX
        public static CodeMsg MIAO_SHA_OVER = new CodeMsg(500500, "商品已经秒杀完毕");
        public static CodeMsg REPEATE_MIAOSHA = new CodeMsg(500501, "不能重复秒杀");
        public static CodeMsg MIAOSHA_FAIL = new CodeMsg(500502, "秒杀失败");
    
        private CodeMsg() {
        
        }
    
        private CodeMsg(int code, String msg) {
        
            this.code = code;
            this.msg = msg;
        }
    
        public int getCode() {
        
            return code;
        }
    
        public void setCode(int code) {
        
            this.code = code;
        }
    
        public String getMsg() {
        
            return msg;
        }
    
        public void setMsg(String msg) {
        
            this.msg = msg;
        }
    
        public CodeMsg fillArgs(Object... args) {
        
            int code = this.code;
            String message = String.format(this.msg, args);
            return new CodeMsg(code, message);
        }
    
        @Override
        public String toString() {
        
            return "CodeMsg [code=" + code + ", msg=" + msg + "]";
        }
    }

新建一个测试接口

package com.hyx.springboot01.controller;
    
    import com.hyx.springboot01.entity.Demo;
    import com.hyx.springboot01.result.CodeMsg;
    import com.hyx.springboot01.result.Result;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.Arrays;
    
    @RestController
    @RequestMapping("/demo2")
    public class NewDemoController {
        
        @RequestMapping("/list")
        public Result list(){
        
            return Result.ok(200,"查询成功",
                    Arrays.asList(
                            new Demo(1,"足球"),
                            new Demo(2,"篮球"),
                            new Demo(3,"排球"),
                            new Demo(4,"羽毛球"),
                            new Demo(5,"台球")
                    ),168);
        }
    
        @RequestMapping("/add")
        public Result add(){
        
            return Result.ok(200,"新增成功");
        }
    
        @RequestMapping("/load")
        public Result load(){
        
            return Result.ok(200,"加载成功",new Demo(3,"排球"));
        }
    
    
        @RequestMapping("/edit")
        public Result edit(){
        
            return Result.ok(200,"修改成功");
        }
    
        @RequestMapping("/delete")
        public Result delete(){
        
            return Result.ok(200,"删除成功");
        }
    
        @RequestMapping("/queryByUser")
        public Result queryByUser(){
        
            return Result.error(CodeMsg.BIND_ERROR.fillArgs("密码等级太低"));
        }
    }

随便测试一下

![image-20230807232244393][]

使用响应封装类配置后代码更加简介了

[image-20230807222029193]: https://img-blog.csdnimg.cn/img_convert/80bfb8db76265740c951302995d0c1b0.png
[image-20230807222726691]: https://img-blog.csdnimg.cn/img_convert/0958d500df20f336b4daa4ef28b01154.png
[image-20230807223609802]: https://img-blog.csdnimg.cn/img_convert/3bf245de82228f998899d23e534cdd3b.png
[image-20230807224628773]: https://img-blog.csdnimg.cn/img_convert/2eb294a496b8c8da7c6a62119d0178c9.png
[image-20230807225632410]: https://img-blog.csdnimg.cn/img_convert/0c235f9a6c6aff13034c678cd475bfb4.png
[image-20230807225648536]: https://img-blog.csdnimg.cn/img_convert/63310639cdcd4fdf8e99a05874545c3c.png
[image-20230807230811114]: https://img-blog.csdnimg.cn/img_convert/993105f7e18ac631bbde9fcb3e74e117.png
[image-20230807230259950]: https://img-blog.csdnimg.cn/img_convert/3bc0169ba32ea47e783c3a2029672787.png
[image-20230807233144695]: https://img-blog.csdnimg.cn/img_convert/b8ffcf60132517cb18c9c40b966c530c.png
[image-20230807232244393]: https://img-blog.csdnimg.cn/img_convert/e2e87bc5a4c02dcb503952d39e450409.png