Spring Boot知识点复习java北有孤酒的博客-

知识点复习： 

1、IoC的具体应用

 装配Bean的注解：
   @Service
   @Component
   @Repository
   @Controller
  
  @Bean : 用在方法上面，将方法的返回值装配成Bean

2、AOP的具体应用
3、MVC
4、RESTfull
5、DAO层

      MySQL、MyBatis
      NoSQL 

事务

 6、拦截器
 7、登录认证

    JWT

8、应用程序打包部署

    操作系统：Linux/Unix
    前后端分离部署：
    
         Webserver   App server
         nginx        tomcat
         HttpServer/nginx   WebSphere/Weblogic/JBoss
    
    部署手册

导excel第三方包：
1、 JXL 
2、POI

 依赖：         <dependency>             <groupId>org.apache.poi</groupId>             <artifactId>poi</artifactId>             <version>4.1.2</version>         </dependency>         <dependency>             <groupId>org.apache.poi</groupId>             <artifactId>poi-ooxml</artifactId>             <version>4.1.2</version>         </dependency>

为了让小伙伴更快对Spring Boot有一个系统的总结,下面以代码形式

所需的工具：idea+MySQL以及postman测试工具

MySQL：

T_EMP表

 CREATE TABLE `T_EMP` (   `empno` int(11) NOT NULL,   `ename` varchar(765) COLLATE utf8_bin DEFAULT NULL,   `mgr` int(11) DEFAULT NULL,   `hiredate` datetime DEFAULT NULL,   `job` varchar(150) COLLATE utf8_bin DEFAULT NULL,   `sal` float DEFAULT NULL,   `comm` float DEFAULT NULL,   `deptno` int(11) DEFAULT NULL,   PRIMARY KEY (`empno`),   KEY `hiredate_idx` (`hiredate`),   KEY `hiredate_name_idx` (`hiredate`,`ename`),   KEY `name_hiredate_idx` (`ename`,`hiredate`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;

T_DEPT表 

 CREATE TABLE `T_DEPT` (   `deptno` int(11) DEFAULT NULL,   `dname` varchar(765) COLLATE utf8_bin DEFAULT NULL,   `loc` varchar(300) COLLATE utf8_bin DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;

 T_EMP表中的数据：

 INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (1,'王慧云',3,'2018-05-02 00:00:00','Java工程师',8000,200,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (2,'唐思远',NULL,'2020-03-12 00:00:00','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (3,'刘早',NULL,'2018-05-03 00:00:00','Java工程师',2506,200,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (4,'周敏',3,'2018-05-03 15:40:17','Java工程师',1500,10,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (5,'刘丽丽',3,'2018-10-10 00:00:00','Java工程师',9001,0,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (6,'汤灿',3,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7,'刘丽丽2',3,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (8,'刘丽丽3',11,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (9,'刘丽丽4',11,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (10,'刘丽丽5',11,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (11,'刘丽丽6',NULL,'2018-10-10 08:08:08','C++工程师',9000,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (12,'刘丽丽x',1,'2018-10-10 00:00:00','C++工程师',9000,0,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (13,'刘丽丽8',1,'2018-10-10 08:08:08','C++工程师',9000,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (14,'刘丽丽9',1,'2018-10-10 08:08:08','C++工程师',9000,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (15,'刘丽丽10',1,'2018-10-10 08:08:08','C++工程师',9000,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (17,'刘丽丽12',1,'2018-10-10 08:08:08','C++工程师',9000,NULL,4); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (18,'刘丽丽13',1,'2018-10-10 00:00:00','C++工程师',9000,3,4); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (19,'昌寒阳',NULL,'2020-03-05 00:00:00',NULL,NULL,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (20,'张三',NULL,'2018-10-10 00:00:00','C++工程师',10000,0,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (21,'刘丽丽16',NULL,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (22,'刘丽丽17',NULL,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (23,'刘丽丽18',NULL,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (24,'马方',NULL,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (25,'王圆',21,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (26,'谢文彬',21,'2018-10-10 00:00:00','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (27,'刘丽丽20',21,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (28,'刘丽丽21',21,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (29,'刘丽丽22',21,'2018-10-10 08:08:08','C++工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (31,'刘丽丽24',21,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (32,'刘丽丽25',21,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (33,'刘丽丽26',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (34,'刘丽丽27',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (35,'刘丽丽28',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (36,'刘丽丽28',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (37,'刘丽丽30',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (38,'刘丽丽31',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (39,'刘丽丽32',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (40,'刘丽丽33',NULL,'2018-10-10 08:08:08','Python工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (41,'刘丽丽x',NULL,'2018-10-10 08:08:08','Java工程师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (43,'jack',NULL,'2018-10-10 08:08:08','Java讲师',9000,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (45,'小丽丽',NULL,'2019-09-16 00:00:00','销售经理',10000,30,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (90,'小崔',NULL,'2020-03-04 00:00:00',NULL,NULL,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (99,'强哥',NULL,'2019-09-26 00:00:00','Java工程师',7776,7788,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (100,'张六哥',NULL,'2019-12-26 00:00:00',NULL,NULL,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (101,'小五',NULL,'2019-12-17 00:00:00',NULL,NULL,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (120,'张芳',NULL,'2019-12-05 11:55:14',NULL,NULL,NULL,5); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (121,'强哥',NULL,'2019-10-10 00:00:00','C工程师',0,0,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (122,'尹俊华Y',NULL,'2019-10-10 00:00:00','Java工程师',4444,0,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (123,'尹俊华Y',NULL,'2019-10-10 00:00:00','Java工程师',0,0,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (124,'唐思远',1,'2020-03-12 00:00:00','Java工程师',10000,4000,5); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (125,'吴昊',1,'2020-03-12 00:00:00','测试主管',12000,1000,4); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (222,'付明强X',NULL,'1998-10-10 08:00:00',NULL,NULL,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (333,'Jordan',NULL,'2020-03-12 00:00:00',NULL,9000,NULL,5); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (334,'Jackson',NULL,'2020-03-12 00:00:00',NULL,9000,NULL,3); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (446,'寒阳X',NULL,'2020-04-16 00:00:00','Java工程师',9000,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (665,'邹鑫3',NULL,'2020-03-04 08:00:00',NULL,NULL,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (666,'何绪辉',NULL,'2020-03-12 00:00:00',NULL,9999,NULL,6); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (667,'谢文彬',NULL,NULL,'Java攻城狮',10000,1,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (669,'陈鹏',NULL,'2020-04-14 00:00:00','程序员',9999,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (777,'唐思远',NULL,'2020-03-17 00:00:00',NULL,4500,NULL,2); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (888,'邹鑫',NULL,'2020-03-23 10:59:07','Java工程师',5000,NULL,NULL); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (993,'兰翔',NULL,'2020-04-16 00:00:00','Java工程师',9990,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7777,'Jams',NULL,'2020-03-25 10:00:46','前端工程师',NULL,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7778,'陈宇',NULL,NULL,NULL,9999,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7779,'陈宇2',NULL,NULL,NULL,8999,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7780,'陈宇3X',NULL,'2020-04-10 00:00:00','Java工程师',7999,NULL,1); INSERT INTO `T_EMP` (`empno`,`ename`,`mgr`,`hiredate`,`job`,`sal`,`comm`,`deptno`) VALUES (7781,'天宇',NULL,'2020-04-08 00:00:00','Java工程师',10000,NULL,NULL);

T_DEPT表 里的数据 

 INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (1,'开发一部','长沙'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (2,'开发二部','北京'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (3,'开发三部','深圳'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (4,'销售部','长沙'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (5,'推广部','长沙'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (6,'公关部','深圳'); INSERT INTO `T_DEPT` (`deptno`,`dname`,`loc`) VALUES (7,'后勤部','长沙'); 

工程目录：

application.properties(配置信息)

 server.port=8080  spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mydb?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai #数据库名 spring.datasource.username=root #数据库密码 spring.datasource.password=root #数据库引擎 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

Dept.java

 package com.example.demo.pojo;  import java.io.Serializable;   public class Dept implements Serializable {      private Integer deptno;     private String dname;     private String loc;      public Dept() {     }      public Dept(Integer deptno, String dname, String loc) {         this.deptno = deptno;         this.dname = dname;         this.loc = loc;     }      public Integer getDeptno() {         return deptno;     }      public void setDeptno(Integer deptno) {         this.deptno = deptno;     }      public String getDname() {         return dname;     }      public void setDname(String dname) {         this.dname = dname;     }      public String getLoc() {         return loc;     }      public void setLoc(String loc) {         this.loc = loc;     } } 

Emp.java

 package com.example.demo.pojo;   import com.fasterxml.jackson.annotation.JsonFormat;  import java.io.Serializable; import java.util.Date;   public class Emp implements Serializable {      private Integer empno;     private String ename;     @JsonFormat(pattern = "yyyy-MM-dd")     private Date hiredate;      private Dept  dept;      public Integer getEmpno() {         return empno;     }      public void setEmpno(Integer empno) {         this.empno = empno;     }      public String getEname() {         return ename;     }      public void setEname(String ename) {         this.ename = ename;     }      public Date getHiredate() {         return hiredate;     }      public void setHiredate(Date hiredate) {         this.hiredate = hiredate;     }      public Dept getDept() {         return dept;     }      public void setDept(Dept dept) {         this.dept = dept;     } } 

ErrorInfo.java

 package com.example.demo.pojo;  public class ErrorInfo<T> {      private Integer code;     private  String info;     private  T data;      public Integer getCode() {         return code;     }      public void setCode(Integer code) {         this.code = code;     }      public String getInfo() {         return info;     }      public void setInfo(String info) {         this.info = info;     }      public T getData() {         return data;     }      public void setData(T data) {         this.data = data;     } } 

IEmpMapper.java

 package com.example.demo.mapper;   import com.example.demo.pojo.Emp; import org.apache.ibatis.annotations.Result; import org.apache.ibatis.annotations.Results; import org.apache.ibatis.annotations.Select;  import java.util.List;    public interface IEmpMapper {      @Select({             "SELECT EMPNO,ENAME,HIREDATE,b.DEPTNO,b.DNAME,LOC",             "FROM T_EMP a LEFT JOIN T_DEPT b",             "ON a.DEPTNO=b.DEPTNO",             "ORDER BY b.DEPTNO ASC"     })     @Results({             @Result(property = "empno", column = "EMPNO"),             @Result(property = "ename", column = "ENAME"),             @Result(property = "hiredate", column = "HIREDATE"),             @Result(property = "dept.deptno", column = "DEPTNO"),             @Result(property = "dept.dname", column = "DNAME"),             @Result(property = "dept.loc", column = "LOC")     })     public List<Emp> query(); } 

IEmpService.java

 package com.example.demo.service;    import com.example.demo.pojo.Emp;  import java.util.List;   public interface IEmpService {      /**      * 得到所有员工信息      * @return      */     public List<Emp> query(); } 

EmpServiceImpl.java

 package com.example.demo.service.impl;   import com.example.demo.mapper.IEmpMapper; import com.example.demo.pojo.Emp; import com.example.demo.service.IEmpService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  import java.util.List;   /**  * @author QuanLijian  */ @Service("empService") public class EmpServiceImpl implements IEmpService {      //需要将DAO注入至服务层     @Autowired     private IEmpMapper empMapper;       /**      * 得到所有员工信息      *      * @return      */     @Override     public List<Emp> query() {         return empMapper.query();     } } 

GlobalException.java

 package com.example.demo.excepetion;  import com.example.demo.pojo.ErrorInfo; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.RestControllerAdvice;  import java.util.HashMap; import java.util.Map;  @RestControllerAdvice public class GlobalException {      /**      * 用于处理异常      * @return      */     @ExceptionHandler(Exception.class) //标记用于处理异常的方法     public ErrorInfo<?> doException(Exception e){         ErrorInfo<Map<String,String>> info=new ErrorInfo<>();         info.setCode(500);         info.setInfo(e.getMessage());          Map<String,String> map=new HashMap<>();         map.put("uid","zhangsan");         map.put("realname","张三");         map.put("sex","F");         info.setData(map);          return info;     } } 

EmpController.java

 package com.example.demo.controller;   import com.example.demo.pojo.Emp; import com.example.demo.service.IEmpService; import org.springframework.http.HttpStatus; import org.springframework.http.ResponseEntity;  import org.springframework.web.bind.annotation.*;  import javax.annotation.Resource; import java.util.List;   @RestController//@Controller+@ResponseBody 组合 @RequestMapping("/api") public class EmpController {      //注入服务层     @Resource(name = "empService")     private IEmpService empService;       //直接返回数据     @GetMapping("/emp")     public ResponseEntity<?> query() {         //调用服务层获得数据         List<Emp> emps = empService.query();         ResponseEntity<?> resp = new ResponseEntity<>(emps, HttpStatus.OK);         return resp;     }      @GetMapping("/emp/{empno}")     public ResponseEntity<?> queryById(@PathVariable("empno") Integer empno){          Emp emp = null;         ResponseEntity<?> resp = new ResponseEntity<>(emp, HttpStatus.OK);         return resp;     }   } 

DemoApplication.java（别忘记@MapperScan）

 package com.example.demo;  import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;  @SpringBootApplication @MapperScan("com.example.**.mapper") public class DemoApplication {      public static void main(String[] args) {         SpringApplication.run(DemoApplication.class, args);     }  } 

程序运行，浏览器打开：

可以看到数据取到了，关于 Spring Boot知识点复习就到这，后续会说的Spring cloud,有问题的小伙伴，欢迎留言！！！