一起学习Spring boot 2.1.X | 第五篇：Mybatis Druid 数据库(注解版)

雨点打透心脏的1/2处 2022-03-30 14:36 189阅读 0赞

## 运行展示 ##

![20190522162341699.png][]

## 正题 ##

Spring boot ：2.１.5RELEASE ；数据库（Mysql、Oracle）；Mybatis；阿里云的连接池 : Druid ；

## 步骤 ##

１．POM依赖

<dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    
    
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    
    
    
    
    
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.16</version>
    </dependency>

２．application.properties

#Mybatis+MySQL+Druid
    #Mysql时区异常URL后添加serverTimezone=GMT%2B8/连接池:typr/初始化连接:initialSize/最大空闲数:maxActive/最小空闲数:minIdle/获取连接等待时间:maxWait/最小等待时间:minEvictableIdleTimeMillis/关闭后不自动提交:defaultAutoCommit
    spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
    spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&serverTimezone=GMT%2B8&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false
    #spring.datasource.url=jdbc:oracle:thin:@127.0.0.1:1521:test
    spring.datasource.username=root
    spring.datasource.password=root
    spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
    
    # 初始化大小，最小，最大
    spring.datasource.initialSize=5
    spring.datasource.minIdle=5
    spring.datasource.maxActive=20
    # 配置获取连接等待超时的时间
    spring.datasource.maxWait=60000
    # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
    spring.datasource.timeBetweenEvictionRunsMillis=60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    spring.datasource.minEvictableIdleTimeMillis=300000
    spring.datasource.validationQuery=SELECT 1 FROM DUAL
    spring.datasource.testWhileIdle=true
    spring.datasource.testOnBorrow=false
    spring.datasource.testOnReturn=false
    # 打开PSCache，并且指定每个连接上PSCache的大小
    spring.datasource.poolPreparedStatements=true
    spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    spring.datasource.filters=stat,wall,log4j
    # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
    spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
    # 合并多个DruidDataSource的监控数据
    #spring.datasource.useGlobalDataSourceStat=true
    
    spring.datasource.defaultAutoCommit=false

3.其他文件生成

User.java

public class User {
    
        public Integer uid;
        public String uname;
        public String upassword;
    
        public Integer getUid() {
            return uid;
        }
    
        public void setUid(Integer uid) {
            this.uid = uid;
        }
    
        public String getUanme() {
            return uname;
        }
    
        public void setUanme(String uanme) {
            this.uname = uanme;
        }
    
        public String getUpassword() {
            return upassword;
        }
    
        public void setUpassword(String upassword) {
            this.upassword = upassword;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "uid=" + uid +
                    ", uname='" + uname + '\'' +
                    ", upassword='" + upassword + '\'' +
                    '}';
        }
    }

UserDao.java

import com.spring.boot.bean.User;
    import org.apache.ibatis.annotations.Select;
    import org.apache.ibatis.annotations.Update;
    
    import java.util.List;
    
    @Mapper
    public interface UserDao {
    
        @Select("select * from user")
        public List<User> AllUser();
    
        @Update("<script> " + "update user" +
                "<set>"+  "<if test='uname!=null'>uname=#{uname},</if>"+
                "<if test='upassword!=null'>upassword=#{upassword},</if>"+
                "</set>"+ "where uid=#{uid}"+
                " </script> ")
        public int Update(User user);
    
    }

UserService.java

import com.spring.boot.bean.User;
    import java.util.List;
    
    public interface UserService {
    
        public List<User> AllUser();
    
        public int Update(User user);
    
    }

UserImpl.java  
主要是注解问题Service可以命名，主要还是看自己的日常使用

import com.spring.boot.bean.User;
    import com.spring.boot.dao.UserDao;
    import com.spring.boot.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import java.util.List;
    
    @Service
    public class UserImpl implements UserService {
    
        @Autowired
        private UserDao userDao;
    
        @Override
        public List<User> AllUser() {
    
            return userDao.AllUser();
        }
    
        @Override
        public int Update(User user) {
            return userDao.Update(user);
        }
    }

UserController.java

import com.spring.boot.bean.User;
    import com.spring.boot.service.impl.UserImpl;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.RequestMapping;
    import javax.servlet.http.HttpServletRequest;
    
    @RestController
    public class UserController {
    
        @Autowired
        private  HttpServletRequest request;
    
        @Autowired
        private UserImpl userimpl;
    
         @RequestMapping("/api/login")
        public String Login(User user) {
    
            HttpSession session = request.getSession();
    
            //存入Session
            //session.setAttribute("user", user);
            //单位为秒，设置为-1时不再失效
            //session.setMaxInactiveInterval(60 * 60 * 24 * 30);
            //注销登陆
            //request.getSession().removeAttribute("user");
    
            return userimpl.UserAll(user).toString();
        }
    }

注：userDao报红解决方法![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxOTIwNzMy_size_16_color_FFFFFF_t_70][]

注：启动类加入注解@MapperScan("路径)  
小编这是Java web项目，@Controller注解是界面、@RestController是写接口

[20190522162341699.png]: /images/20220330/13e9a8a397a949f383694f6c4f55f088.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxOTIwNzMy_size_16_color_FFFFFF_t_70]: /images/20220330/abb7166bd3f14dfd9fdfa2d1beff6c83.png