SpringBoot from getting started to giving up, Chapter 4
I. springboot integrates JDBC and DRUID
1,POM
<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>
2,application.yml
server: port: 8080 spring: datasource: username: root password: 123456 url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC driver-class-name: com.mysql.jdbc.Driver
3,jdbcTemplate
@RestController public class HelloJdbcController { @Autowired private JdbcTemplate jdbcTemplate; @GetMapping("/jdbcData") public List jdbcData(){ return jdbcTemplate.queryForList("select * from student"); } }
4, result
[{"id":1,"stuname":"s1","classid":1},{"id":2,"stuname":"s2","classid":1}, {"id":3,"stuname":"s3","classid":1},{"id":4,"stuname":"s4","classid":2}, {"id":5,"stuname":"s5","classid":3},{"id":6,"stuname":"s6","classid":3}]
5. Source code interpretation
Location: JDBC under org.springframework.boot: spring boot autoconfigure: 2.2.1.release package
DataSource injection
DataSourceConfiguration imports the
abstract class DataSourceConfiguration { protected static <T> T createDataSource(DataSourceProperties properties, Class<? extends DataSource> type) { return (T) properties.initializeDataSourceBuilder().type(type).build(); } @Configuration(proxyBeanMethods = false) @ConditionalOnClass(HikariDataSource.class) @ConditionalOnMissingBean(DataSource.class) @ConditionalOnProperty(name = "spring.datasource.type", havingValue = "com.zaxxer.hikari.HikariDataSource", matchIfMissing = true) static class Hikari { @Bean @ConfigurationProperties(prefix = "spring.datasource.hikari") HikariDataSource dataSource(DataSourceProperties properties) { HikariDataSource dataSource = createDataSource(properties, HikariDataSource.class); if (StringUtils.hasText(properties.getName())) { dataSource.setPoolName(properties.getName()); } return dataSource; } } .... }
We can see from the above: if we configure spring.datasource.type as com.alibaba.druid.pool.DruidDataSource and import the related Druid package, we can also replace the data source
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency>
DataSourceProperties injects the configuration information in the application into the
@ConfigurationProperties(prefix = "spring.datasource") public class DataSourceProperties implements BeanClassLoaderAware, InitializingBean{ private String url; private String username; private String password; private String driverClassName; private List<String> schema; .... public DataSourceBuilder<?> initializeDataSourceBuilder() { return DataSourceBuilder.create(getClassLoader()).type(getType()).driverClassName(determineDriverClassName()) .url(determineUrl()).username(determineUsername()).password(determinePassword()); } }
We can configure automatic table creation statements in YML:
spring: datasource: schema: - classpath:user.sql - classpath:order.sql
The automatic configuration source code is as follows:
boolean createSchema() { List<Resource> scripts = getScripts("spring.datasource.schema", this.properties.getSchema(), "schema"); if (!scripts.isEmpty()) { if (!isEnabled()) { logger.debug("Initialization disabled (not running DDL scripts)"); return false; } String username = this.properties.getSchemaUsername(); String password = this.properties.getSchemaPassword(); runScripts(scripts, username, password); } return !scripts.isEmpty(); }
6. Integrate DRUID
pom
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency>
YML
server: port: 8080 spring: datasource: username: root password: 123456 url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC driver-class-name: com.mysql.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource druid: initial-size: 8 min-idle: 1 max-active: 20 max-wait: 60000 time-between-eviction-runsMillis: 60000 min-evictable-idle-timeMillis: 300000 validation-query: select 'x' FROM DUAL test-while-idle: true test-on-borrow: false test-on-return: false pool-prepared-statements: true max-open-prepared-statements: 20 max-pool-prepared-statement-per-connection-size: 20 filters: stat connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 use-global-data-source-stat: true //The following can also be added: #Monitoring configuration # For the configuration of WebStatFilter, please refer to the Druid Wiki, configuration, and configure WebStatFilter spring.datasource.druid.web-stat-filter.enabled= #Enable StatFilter default value true spring.datasource.druid.web-stat-filter.url-pattern= spring.datasource.druid.web-stat-filter.exclusions= spring.datasource.druid.web-stat-filter.session-stat-enable= spring.datasource.druid.web-stat-filter.session-stat-max-count= spring.datasource.druid.web-stat-filter.principal-session-name= spring.datasource.druid.web-stat-filter.principal-cookie-name= spring.datasource.druid.web-stat-filter.profile-enable= # For StatViewServlet configuration, please refer to Druid Wiki for instructions, and configure StatViewServlet configuration spring.datasource.druid.stat-view-servlet.enabled= #Enable StatViewServlet default value true spring.datasource.druid.stat-view-servlet.url-pattern= spring.datasource.druid.stat-view-servlet.reset-enable= spring.datasource.druid.stat-view-servlet.login-username= spring.datasource.druid.stat-view-servlet.login-password= spring.datasource.druid.stat-view-servlet.allow= spring.datasource.druid.stat-view-servlet.deny=
Start class APP
@SpringBootApplication public class BootJdbcApplication { public static void main(String[] args) { SpringApplication.run(BootJdbcApplication.class, args); } }
Visit:
Note: if Druid spring boot starter is not introduced, it is as follows
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.10</version> </dependency>
Some column parameters in YML cannot be automatically added to DruidDataSource. We need to add code to the configuration file as follows:
@Bean @ConfigurationProperties(prefix = "spring.datasource")//The parameters under spring.datasource will be automatically injected into the DruidDataSource public DataSource getDataSource() { return new DruidDataSource(); }
YML remove DRUID
server: port: 8080 spring: datasource: username: root password: 123456 url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC driver-class-name: com.mysql.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource initial-size: 8 min-idle: 1 max-active: 20 max-wait: 60000 time-between-eviction-runsMillis: 60000 min-evictable-idle-timeMillis: 300000 validation-query: select 'x' FROM DUAL test-while-idle: true test-on-borrow: false test-on-return: false pool-prepared-statements: true max-open-prepared-statements: 20 max-pool-prepared-statement-per-connection-size: 20 filters: stat connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 use-global-data-source-stat: true
Because the configuration source code in Druid spring boot starter is as follows:
@ConfigurationProperties("spring.datasource.druid") public class DruidStatProperties { }
And added in the startup class
@Bean public ServletRegistrationBean druidStatViewServlet() { //ServletRegistrationBean provides the registration of the class ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*"); //Add initialization parameter: initParams //White list: servletRegistrationBean.addInitParameter("allow", "127.0.0.1"); //IP blacklist (deny takes precedence over allow when it exists at the same time) //If deny is met, it will prompt: sorry, you are not allowed to view this page servletRegistrationBean.addInitParameter("deny", "192.168.1.73"); //Account and password for logging in to view information servletRegistrationBean.addInitParameter("loginUsername", "admin"); servletRegistrationBean.addInitParameter("loginPassword", "123456"); servletRegistrationBean.addInitParameter("resetEnable", "false"); return servletRegistrationBean; } @Bean public FilterRegistrationBean druidStatFilter() { FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter()); //Add filter rule filterRegistrationBean.addUrlPatterns("/*"); //Add formatting information to ignore filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif," + "*.jpg,*.png, *.css,*.ico,/druid/*"); return filterRegistrationBean; }
II. SpringBoot integrates Mybatis
1,POM
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency>
Let's look at the jar package dependency of mybatis
2,entity
@Data @ToString public class Student { private Integer id; private String stuName; private Integer classId; }
3,mapper
//Or directly add @ MapperScan scanning package on startup class -- > recommend @ MapperScan @Mapper public interface StudentMapper { List<Student> findAll(); }
4,Controller
@RestController public class HelloJdbcController { @Autowired private StudentMapper studentMapper; @GetMapping("/findAll") public List<Student> findAllStudent(){ return studentMapper.findAll(); } }
5,Mapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.lee.bootjdbc.mapper.StudentMapper"> <select id="findAll" resultType="com.lee.bootjdbc.entity.Student"> select * from student </select> </mapper>
6. Global configuration of mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <settings> <setting name="mapUnderscoreToCamelCase" value="true"/> </settings> </configuration>
7,application.yml
server: port: 8080 spring: datasource: username: root password: 123456 url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC driver-class-name: com.mysql.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource druid: initial-size: 8 min-idle: 1 max-active: 20 max-wait: 60000 time-between-eviction-runsMillis: 60000 min-evictable-idle-timeMillis: 300000 validation-query: select 'x' FROM DUAL test-while-idle: true test-on-borrow: false test-on-return: false pool-prepared-statements: true max-open-prepared-statements: 20 max-pool-prepared-statement-per-connection-size: 20 filters: stat connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 use-global-data-source-stat: true mybatis: config-location: classpath:mybatis/mybatis-config.xml mapper-locations: classpath:mybatis/mapper/*.xml
8. Access test
http://localhost:8080/findAll //Result: [{"id":1,"stuName":"s1","classId":1},{"id":2,"stuName":"s2","classId":1}, {"id":3,"stuName":"s3","classId":1},{"id":4,"stuName":"s4","classId":2}, {"id":5,"stuName":"s5","classId":3},{"id":6,"stuName":"s6","classId":3}]
9. Source code analysis
Under the autoconfigure package in org.mybatis.spring.boot:mybatis-spring-boot-autoconfigure:1.3.1
MybatisAutoConfiguration
Here, sqlSessionFactory is injected into mybatis, and configuration information is loaded automatically
@Configuration@ConditionalOnClass({SqlSessionFactory.class, SqlSessionFactoryBean.class})@ConditionalOnBean({DataSource.class})@EnableConfigurationProperties({MybatisProperties.class})@AutoConfigureAfter({DataSourceAutoConfiguration.class})public class MybatisAutoConfiguration { @Bean @ConditionalOnMissingBean public SqlSessionFactory sqlSessionFactory(DataSource dataSource){ ... } @Bean @ConditionalOnMissingBean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) { ... } public static class AutoConfiguredMapperScannerRegistrar{ } public void setBeanFactory(BeanFactory beanFactory){ this.beanFactory = beanFactory; } }
The configuration information of mybatis in the application will be loaded here, and start with mybatis
@ConfigurationProperties( prefix = "mybatis") public class MybatisProperties { public static final String MYBATIS_PREFIX = "mybatis"; private String configLocation; private String[] mapperLocations; private String typeAliasesPackage; private String typeHandlersPackage; private boolean checkConfigLocation = false; private ExecutorType executorType; private Properties configurationProperties; ... }