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springboot_數據訪問之mybatis整合

close all dst from dao層 版本 template 編寫 text

一:引言:

    大部分系統都涉及到數據訪問,數據庫包SQL(關系型數據庫)和NOSQL(非關系型數據庫),SQL包括:sqlserver,Oracle,Mysql;NOSQL包括:MongoDB和redis。

二:spring boot與jdbc整合

1.1 首先添加依賴

     <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>

1.2 數據源配置

  

spring:
  datasource:
    url: jdbc:mysql://192.168.1.102:3306/jdbc
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver

測試類:測試:

@RunWith(SpringRunner.class)
@SpringBootTest
public class springbootjdbc {
    @Autowired
    DataSource dataSource;

    @Test
    public void contextLoads() throws SQLException {
        System.out.println("---------------");
        System.out.println(dataSource.getClass());
        Connection connection 
= dataSource.getConnection(); System.out.println("================="); System.out.println(connection); connection.close(); } }

  控制臺輸出:

---------------
class com.zaxxer.hikari.HikariDataSource
2019-05-03 09:25:32.889  INFO 13768 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2019-05-03 09:25:33.500  INFO 13768 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
=================
[email protected] wrapping [email protected]

springboot默認的數據源就是:class com.zaxxer.hikari.HikariDataSource,數據源的相關配置都在DataSourceProperties裏面;

我們也可以自己默認數據源:spring.datasource.type可以自定義。

1.3 DataSourceInitializer

  作用:

?     1)、runSchemaScripts();運行建表語句;

?     2)、runDataScripts();運行插入數據的sql語句;

默認只需要將文件命名為: 

schema-*.sql、data-*.sql
默認規則:schema.sql,schema-all.sql;
可以使用   
    schema:
      - classpath:department.sql
      指定位置

1.4 操作數據庫

  springboot自動配置了JdbcTemplate操作數據庫。

@Controller
public class jdbc {
    @Autowired
    JdbcTemplate jdbcTemplate;

    @ResponseBody
    @RequestMapping("/h1")
    public Map<String, Object> selectAll() {
       List< Map<String, Object>> maps = jdbcTemplate.queryForList("select  *from user ");
        System.out.println(maps.toString());
        return  maps.get(0);
    }
}

訪問地址:http://localhost:8686/h1

技術分享圖片

控制臺打印:[{id=1, name=lisi, age=12}, {id=2, name=wangwu, age=13}]

二:整合Druid數據源

1.1 導入依賴(版本可選擇最新的)

  <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>

1.2 .1配置文件:

spring:
  datasource:
    url: jdbc:mysql://192.168.1.102:3306/jdbc
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
   #數據源其他配置
    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
  #配置監控統計攔截的filters,去掉後監控界面sql無法統計,‘wall‘用於防火墻
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

1.2.2 編寫配置類 druidConfig 並以引入日誌依賴

@Configuration
public class druidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid() {
        return new DruidDataSource();
    }
}
      <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

在之前的測試類中:debug測試:

  技術分享圖片

  可以看到和我們之前在配置文件配置的一樣。

1.2.3 在配置類中 配置druid後臺監控;

@Configuration
public class druidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid() {
        return new DruidDataSource();
    }
//    配置Druid的監控
//    1、配置一個管理後臺的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String,String> initParams = new HashMap<>();

        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");
        //默認就是允許所有訪問
        initParams.put("deny","192.168.15.21");
        bean.setInitParameters(initParams);
        return bean;
    }

    //2、配置一個web監控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());
        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*");

        bean.setInitParameters(initParams);
        bean.setUrlPatterns(Arrays.asList("/*"));
        return  bean;
    }

}

這樣就可以通過後臺監控數據源的訪問情況了。

輸入:

  技術分享圖片

三:整合mybatis

  1.1添加依賴

      <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-sta1rter</artifactId>
            <version>1.3.2</version>
        </dependency>

1.2.1 註解版

  1)、配置數據源相關屬性(見上一節Druid)

?    2)、給數據庫建表

?    3)、創建JavaBean

  dao層:

@Mapper
public interface userMapper {
    @Select("select *from user where id=#{id}")
    User selelctById(Integer id);

    @Delete("delete from user where id=#{id}")
    Integer delectById(Integer id);

    @Insert("insert into user(name,age) values(#{name},#{age}) ")
    User insertUser(User user);

    @Update("update user set name=#{name}where id=#{id}")
    Integer updateById(Integer id);
}

測試userController:

  

@RestController
public class UserController {

    @Autowired
    userMapper usermapper;

    @RequestMapping("/selectById")
    public User selectById(){
        return usermapper.selelctById(2);
    }
}

測試結果:

  技術分享圖片

1.2.2 配置文件版

配置文件添加:

mybatis:
  mapper-locations: classpath:mybatis/mapper/*.xml  指定sql映射文件的位置

type-aliases-package: com.springboot.springboot.pojo 指定實體類所在的包

springboot_數據訪問之mybatis整合