<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

spring:
  datasource:
    username: root
    password: 123456
    #?serverTimezone=UTC解決時區(qū)的報錯
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8

package com.kk;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootTest
class Springboot04DataApplicationTests {

    @Autowired
    DataSource dataSource;
    @Test
    void contextLoads() throws SQLException {
        //查看默認的數(shù)據(jù)源 class com.zaxxer.hikari.HikariDataSource   dbcp
        System.out.println(dataSource.getClass());
        //獲得數(shù)據(jù)庫連接
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();


    }

}

@Bean
public ConfigurableServletWebServerFactory webServerFactory() {
    TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory();
    factory.addConnectorCustomizers(new TomcatConnectorCustomizer() {
        @Override
        public void customize(Connector connector) {
            connector.setProperty("relaxedQueryChars", "|{}[]");
        }
    });
    return factory;
}

package com.kk.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;
import java.util.Map;

@RestController
public class JDBCController {
    
    //JdbcTemplate 是 core 包的核心類，用于簡化 JDBC操作，還能避免一些常見的錯誤，如忘記關閉數(shù)據(jù)庫連接
    //Spring Boot 默認提供了數(shù)據(jù)源，默認提供了 org.springframework.jdbc.core.JdbcTemplate
    //JdbcTemplate 中會自己注入數(shù)據(jù)源，使用起來也不用再自己來關閉數(shù)據(jù)庫連接
    @Autowired
    JdbcTemplate jdbcTemplate;
    
   	//查詢數(shù)據(jù)庫的所有信息
    //沒有實體類，數(shù)據(jù)庫中的東西怎么獲取? Map
   	//List 中的1個 Map 對應數(shù)據(jù)庫的 1行數(shù)據(jù)
    //Map 中的 key 對應數(shù)據(jù)庫的字段名，value 對應數(shù)據(jù)庫的字段值
    @GetMapping("/userList")
    public List<Map<String ,Object>> userList(){
        String sql="select * from user";
        List<Map<String, Object>> list_maps = jdbcTemplate.queryForList(sql);
        return list_maps;
    }

    @GetMapping("/addUser")
    public String addUser(){
        String sql="insert into mybatis.user(id,name,pwd) values(2,'dabai','123456')";
       jdbcTemplate.update(sql);
        return "update-ok";
    }

    @GetMapping("/updateUser/{id}")
    public String updateUser(@PathVariable("id") int id){
        String sql="update mybatis.user set name=?,pwd=? where id="+id;
        //封裝
        Object[] objects = new Object[2];
        objects[0]="xiaobai";
        objects[1]="9999999";
        jdbcTemplate.update(sql,objects);
        return "updateUser-ok";
    }

    @GetMapping("/deleteUser/{id}")
    public String deleteUser(@PathVariable("id") int id){
        String sql="delete from mybatis.user where id=?";
        jdbcTemplate.update(sql,id);
        return "deleteUser-ok";
    }
}

	 @Configuration
    @ConditionalOnMissingBean({DataSource.class})
    @ConditionalOnProperty(
        name = {"spring.datasource.type"}
    )
    static class Generic {
        Generic() {
        }

        @Bean
        public DataSource dataSource(DataSourceProperties properties) {
            return properties.initializeDataSourceBuilder().build();
        }
    }

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.6</version>
</dependency>

type: com.alibaba.druid.pool.DruidDataSource

#Spring Boot 默認是不注入這些屬性值的，需要自己綁定
#druid 數(shù)據(jù)源專有配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
#配置監(jiān)控統(tǒng)計攔截的filters，stat:監(jiān)控統(tǒng)計、log4j：日志記錄、wall：防御sql注入
#如果允許時報錯  java.lang.ClassNotFoundException: org.apache.log4j.Priority
#則導入 log4j 依賴即可，Maven 地址： https://mvnrepository.com/artifact/log4j/log4j
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>

public class SpringbootDemoDataApplicationTests {

    //注入數(shù)據(jù)源
    @Autowired
    DataSource dataSource;

    @Test
    public void contextLoads() throws SQLException {
        //看一下默認數(shù)據(jù)源
        System.out.println(dataSource.getClass());
        //獲得連接
        Connection connection =   dataSource.getConnection();
        System.out.println(connection);

        DruidDataSource druidDataSource = (DruidDataSource) dataSource;
        System.out.println("druidDataSource 數(shù)據(jù)源最大連接數(shù)：" + druidDataSource.getMaxActive());
        System.out.println("druidDataSource 數(shù)據(jù)源初始化連接數(shù)：" + druidDataSource.getInitialSize());

        //關閉連接
        connection.close();
    }

}

package com.kk.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.Filter;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")  //關聯(lián)application.yaml中的spring.datasource
    @Bean
    public DataSource druidDataSource(){
        return new DruidDataSource();
    }

    //配置 Druid 監(jiān)控管理后臺的Servlet；
    //內(nèi)置 Servler 容器時沒有web.xml文件，所以使用 Spring Boot 的注冊 Servlet 方式
    @Bean
    public ServletRegistrationBean statViewServlet() {
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");

        Map<String, String> initParams = new HashMap<>();
        initParams.put("loginUsername", "admin"); //后臺管理界面的登錄賬號
        initParams.put("loginPassword", "123456"); //后臺管理界面的登錄密碼

        //后臺允許誰可以訪問
        //initParams.put("allow", "localhost")：表示只有本機可以訪問
        //initParams.put("allow", "")：為空或者為null時，表示允許所有訪問
        initParams.put("allow", "");
        //deny：Druid 后臺拒絕誰訪問
        //initParams.put("kuangshen", "192.168.1.20");表示禁止此ip訪問

        //設置初始化參數(shù)
        bean.setInitParameters(initParams);
        return bean;
        //這些參數(shù)可以在 com.alibaba.druid.support.http.StatViewServlet 的父類 com.alibaba.druid.support.http.ResourceServlet 中找到
    }



    //filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>();
        bean.setFilter(new WebStatFilter());

        //可以過濾哪些請求？
        HashMap<String, String> initParameters = new HashMap<>();
        //這些東西不進行統(tǒng)計
        initParameters.put("exclusions","*.js,*.css,/druid/*");


        bean.setInitParameters(initParameters);
        return bean;
    }
}

//filter
@Bean
public FilterRegistrationBean webStatFilter(){
    FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>();
    bean.setFilter(new WebStatFilter());

    //可以過濾哪些請求？
    HashMap<String, String> initParameters = new HashMap<>();
    //這些東西不進行統(tǒng)計
    initParameters.put("exclusions","*.js,*.css,/druid/*");


    bean.setInitParameters(initParameters);
    return bean;
}

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
</dependency>

# 數(shù)據(jù)庫驅(qū)動：
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
# 數(shù)據(jù)源名稱
spring.datasource.name=defaultDataSource
# 數(shù)據(jù)庫連接地址
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
# 數(shù)據(jù)庫用戶名&密碼：
spring.datasource.username=root
spring.datasource.password=123456

package com.kk;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.SQLException;

@SpringBootTest
class Springboot05MybatisApplicationTests {

    @Autowired
    DataSource dataSource;
    @Test
    void contextLoads() throws SQLException {
        System.out.println(dataSource.getClass());
        System.out.println(dataSource.getConnection());
    }

}

package com.kk;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.SQLException;

@SpringBootTest
class Springboot05MybatisApplicationTests {

    @Autowired
    DataSource dataSource;
    @Test
    void contextLoads() throws SQLException {
        System.out.println(dataSource.getClass());
        System.out.println(dataSource.getConnection());
    }

}

package com.kk.mapper;

import com.kk.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

//這個注解表示 這是一個mybatis 的mapper類
@Mapper  //controller層
@Repository  //spring
public interface UserMapper {


    List<User> queryUserList();

    User queryUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);

}

package com.kk.controller;

import com.kk.mapper.UserMapper;
import com.kk.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/queryUserList")
    public List<User> queryUserList(){
        List<User> userList = userMapper.queryUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        return userList;
    }

    //根據(jù)id選擇用戶
    @GetMapping("/queryUserById")
    public String selectUserById(){
        User user = userMapper.queryUserById(1);
        System.out.println(user);
        return "ok";
    }
    //添加一個用戶
    @GetMapping("/addUser")
    public String addUser(){
        userMapper.addUser(new User(1,"大黃","9999999"));
        userMapper.addUser(new User(3,"大黃","9999999"));
        userMapper.addUser(new User(4,"大黃","9999999"));

        return "ok";
    }
    //修改一個用戶
    @GetMapping("/updateUser")
    public String updateUser(){
        userMapper.updateUser(new User(5,"黃毛","999999"));
        return "ok";
    }
    //根據(jù)id刪除用戶
    @GetMapping("/deleteUser")
    public String deleteUser(){
        userMapper.deleteUser(5);
        return "ok";
    }
}

# 整合mybatis
# 設置別名以及設置能讓spring識別
#指定myBatis的核心配置文件與Mapper映射文件
# 注意：對應實體類的路徑
mybatis.type-aliases-package=com.kk.pojo
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

@ConfigurationProperties(
    prefix = "mybatis"
)
public class MybatisProperties {
    public static final String MYBATIS_PREFIX = "mybatis";
    private static final ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
    private String configLocation;
    private String[] mapperLocations;
    private String typeAliasesPackage;
    private Class<?> typeAliasesSuperType;
    private String typeHandlersPackage;
    private boolean checkConfigLocation = false;
    private ExecutorType executorType;
    private Class<? extends LanguageDriver> defaultScriptingLanguageDriver;
    private Properties configurationProperties;
    @NestedConfigurationProperty
    private Configuration configuration;