springboot使用Mybatis(xml和注解)过程全解析

 <?xml version="1.0" encoding="UTF-8"?>

 4.0.0
 com.example
 mybatis-test
 0.0.1-SNAPSHOT
 jar
 mybatis-test
 Demo project for Spring Boot
 
  org.springframework.boot
  spring-boot-starter-parent
  2.0.3.RELEASE
   
 
 
  UTF-8
  UTF-8
  1.8
 
 
  
   org.springframework.boot
   spring-boot-starter-web
  
  
   MySQL
   mysql-connector-java
   runtime
  
  
  
   org.mybatis.spring.boot
   mybatis-spring-boot-starter
   1.3.2
  
  
  
   com.alibaba
   druid-spring-boot-starter
   1.1.9
  
  
  
   com.github.pagehelper
   pagehelper-spring-boot-starter
   1.2.5
  
  
   org.springframework.boot
   spring-boot-starter-test
   test
  
 
 
  
   
    org.springframework.boot
    spring-boot-maven-plugin
   
  
 

@SpringBootApplication
@MapperScan("com.example.mybatistest.dao")
public class MybatisTestApplication {
 public static void main(String[] args) {
  SpringApplication.run(MybatisTestApplication.class, args);
 }
}

mybatis:
 #对应实体类路径
 type-aliases-package: com.example.mybatistest.entity
 #对应mapper映射文件路径
 mapper-locations: classpath:mapper/*.xml
#pagehelper物理分页配置
pagehelper:
 helper-dialect: mysql
 reasonable: true
 support-methods-arguments: true
 params: count=countSql
 returnPageInfo: check
server:
 port: 8081
spring:
 datasource:
 name: mysqlTest
 type: com.alibaba.druid.pool.DruidDataSource
 #druid连接池相关配置
 druid:
  #监控拦截统计的filters
  filters: stat
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true
  username: root
  password: 123456
  #配置初始化大小，最小，最大
  initial-size: 1
  min-idle: 1
  max-active: 20
  #获取连接等待超时时间
  max-wait: 6000
  #间隔多久检测一次需要关闭的空闲连接
  time-between-eviction-runs-millis: 60000
  #一个连接在池中的最小生存时间
  min-evictable-idle-time-millis: 300000
  #打开PSCache，并指定每个连接上PSCache的大小。oracle设置为true，mysql设置为false。分库分表设置较多推荐设置
  pool-prepared-statements: false
  max-pool-prepared-statement-per-connection-size: 20
 http:
 encoding:
  charset: utf-8
  enabled: true

CREATE TABLE `user` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(255) NOT NULL,
 `age` tinyint(4) NOT NULL DEFAULT '0',
 `password` varchar(255) NOT NULL DEFAULT '123456',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

public class User {
 private int id;
 private String name;
 private int age;
 private String password;
 public User(int id, String name, int age, String password) {
  this.id = id;
  this.name = name;
  this.age = age;
  this.password = password;
 }
 public User(){}
 //getter setter自行添加
}

public interface UserDao {
 //插入用户
 int insert(User user);
 //根据id查询
 User selectById(String id);
 //查询所有
 List selectAll();
}

<?xml version="1.0" encoding="utf-8" ?>


 
  user
 
 
  id,name,age,password
 
 
  INSERT INTO 
  
   name,password,
   
    age
   
  
  
   #{name,jdbcType=VARCHAR},#{password},
   
    #{age}
   
  
 
 
  select
   
  from
   
  where id=#{id}
 
 
  select
   
  from
   
 

@Component
public class UserService {
 @Autowired
 private UserDao userDao;
 public User getByUserId(String id){
  return userDao.selectById(id);
 }
 //获取全部用户
 public List getAll(){
  return userDao.selectAll();
 }
 //测试分页
 public PageInfo getAll(int pageNum,int pageSize){
  PageHelper.startPage(pageNum,pageSize);
  List users = userDao.selectAll();
  System.out.println(users.size());
  PageInfo result = new PageInfo<>(users);
  return result;
 }
 public int insert(User user){
  return userDao.insert(user);
 }
}

@RestController
public class UserController {
 @Autowired
 private UserService userService;
 @GetMapping("/user/{userId}")
 public User getUser(@PathVariable String userId){
  return userService.getByUserId(userId);
 }
 @GetMapping("/user")
 public List getAll(){
  return userService.getAll();
 }
 @GetMapping("/user/page/{pageNum}")
 public Object getPage(@PathVariable int pageNum,
       @RequestParam(name = "pageSize",required = false,defaultValue = "10") int pageSize){
  return userService.getAll(pageNum,pageSize);
 }
 @PostMapping("/user")
 public Object addOne(User user){
  userService.insert(user);
  return user;
 }
}

public interface UserDao {
 //插入用户
 @Insert("insert into user(name,age,password) value(#{name},#{age},#{password})")
 @Options(useGeneratedKeys=true,keyColumn="id",keyProperty="id")
 int insert(User user);
 //根据id查询
 @Select("select * from user where id=#{id}")
 User selectById(String id);
 //查询所有
 @Select("select * from user")
 List selectAll();
}