Spring系列课程（6）— 注解编程

@Bean public DataSource dataSource(){ DruidDataSource dataSource = new DruidDataSource(); dataSource.setDriverClassName(“”); dataSource.setUrl(); … return dataSource; }

1. SqlSessionFactoryBean

   classpath:com.baizhiedu.mapper/*Mapper.xml

   @Bean public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource){

     SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
     sqlSessionFactoryBean.setDataSource(dataSource);
     sqlSessionFactoryBean.setTypeAliasesPackage("");
     ...
     return sqlSessionFactoryBean;

   }

2. MapperScannerConfigure

   @MapperScan(basePackages={“com.baizhiedu.dao”}) —-> 配置bean完成 ```

• 编码 ```markdown

1. 实体
2. 表
3. DAO接口
4. Mapper文件 ```

• 1. MapperLocations编码时通配的写法 ```java //设置Mapper文件的路径 sqlSessionFactoryBean.setMapperLocations(Resource..); Resource resouce = new ClassPathResouce(“UserDAOMapper.xml”)

sqlSessionFactoryBean.setMapperLocations(new ClassPathResource(“UserDAOMapper.xml”));

classpath:com.baizhiedu.mapper/*Mapper.xml 一组Mapper文件

ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); Resource[] resources = resolver.getResources(“com.baizhi.mapper/*Mapper.xml”); sqlSessionFactoryBean.setMapperLocations(resources)

- 2. 配置Bean数据耦合的问题
```java
mybatis.driverClassName = com.mysql.jdbc.Driver
mybatis.url = jdbc:mysql://localhost:3306/suns?useSSL=false
mybatis.username = root
mybatis.password = 123456
mybatis.typeAliasesPackages = com.baizhiedu.mybatis
mybatis.mapperLocations = com.baizhiedu.mapper/*Mapper.xml
@Component
@PropertySource("classpath:mybatis.properties")
public class MybatisProperties {
    @Value("${mybatis.driverClassName}")
    private String driverClassName;
    @Value("${mybatis.url}")
    private String url;
    @Value("${mybatis.username}")
    private String username;
    @Value("${mybatis.password}")
    private String password;
    @Value("${mybatis.typeAliasesPackages}")
    private String typeAliasesPackages;
    @Value("${mybatis.mapperLocations}")
    private String mapperLocations;
}
public class MyBatisAutoConfiguration {
    @Autowired
    private MybatisProperties mybatisProperties;
    @Bean
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(mybatisProperties.getDriverClassName());
        dataSource.setUrl(mybatisProperties.getUrl());
        dataSource.setUsername(mybatisProperties.getUsername());
        dataSource.setPassword(mybatisProperties.getPassword());
        return dataSource;
    }
    @Bean
    public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource) {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setTypeAliasesPackage(mybatisProperties.getTypeAliasesPackages());
        //sqlSessionFactoryBean.setMapperLocations(new ClassPathResource("UserDAOMapper.xml"));
        try {
            ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            Resource[] resources = resolver.getResources(mybatisProperties.getMapperLocations());
            sqlSessionFactoryBean.setMapperLocations(resources);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sqlSessionFactoryBean;
    }
}

10. 纯注解版事务编程

1. 原始对象 XXXService
   <bean id="userService" class="com.baizhiedu.service.UserServiceImpl">
     <property name="userDAO" ref="userDAO"/>
   </bean>
   @Service
   public class UserServiceImpl implements UserService{
         @Autowired
         private UserDAO userDAO;
   }
2. 额外功能
   <!--DataSourceTransactionManager-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource" ref="dataSource"/>
    </bean>
    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(DataSource dataSource){
          DataSourceTransactionManager dstm = new DataSourceTransactionManager();
          dstm.setDataSource(dataSource);
          return dstm 
    }
3. 事务属性
    @Transactional
    @Service
    public class UserServiceImpl implements UserService {
        @Autowired
        private UserDAO userDAO;
4. 基于Schema的事务配置 
   <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>
   @EnableTransactionManager ---> 配置Bean

1. ApplicationContext ctx = new AnnotationConfigApplicationContext("com.baizhiedu.mybatis");
   SpringBoot 实现思想
2. 注解版MVC整合，SpringMVC中进行详细讲解
   SpringMyBatis --->DAO  事务基于注解 --> Service   Controller 
   org.springframework.web.context.ContextLoaderListener ---> XML工厂 无法提供 new AnnotationConfigApplicationContext

11. Spring框架中YML的使用

1. 什么是YML

YML(YAML)是一种新形式的配置文件，比XML更简单，比Properties更强大。
YAML is a nice human-readable format for configuration, and it has some useful hierarchical properties. It's more or less a superset of JSON, so it has a lot of similar features.

2. Properties进行配置问题

1. Properties表达过于繁琐,无法表达数据的内在联系. 
2. Properties无法表达对象 集合类型

3. YML语法简介

1. 定义yml文件 
   xxx.yml xxx.yaml
2. 语法
   1. 基本语法
      name: suns
      password: 123456
   2. 对象概念 
      account: 
         id: 1
         password: 123456
   3. 定义集合 
      service: 
         - 11111
         - 22222

4. Spring与YML集成思路的分析

1. 准备yml配置文件 
   init.yml
   name: suns
   password: 123456
2. 读取yml 转换成 Properties
   YamlPropertiesFactoryBean.setResources( yml配置文件的路径 ) new ClassPathResource();
   YamlPropertiesFactoryBean.getObject() ---> Properties 
3. 应用PropertySourcesPlaceholderConfigurer
   PropertySourcesPlaceholderConfigurer.setProperties();
4. 类中 @Value注解 注入

5. Spring与YML集成编码

• 环境搭建

  <dependency>
  <groupId>org.yaml</groupId>
  <artifactId>snakeyaml</artifactId>
  <version>1.23</version>
  </dependency>
  最低版本 1.18

• 编码 ```java

1. 准备yml配置文件

2. 配置Bean中操作 完成YAML读取 与 PropertySourcePlaceholderConfigure的创建 @Bean public PropertySourcesPlaceholderConfigurer configurer() {

    YamlPropertiesFactoryBean yamlPropertiesFactoryBean = new YamlPropertiesFactoryBean();
    yamlPropertiesFactoryBean.setResources(new ClassPathResource("init.yml"));
    Properties properties = yamlPropertiesFactoryBean.getObject();
    PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
    configurer.setProperties(properties);
    return configurer;

   }

3. 类 加入 @Value注解 ```

6. Spring与YML集成的问题

1. 集合处理的问题
   SpringEL表达式解决
   @Value("#{'${list}'.split(',')}")
2. 对象类型的YAML进行配置时 过于繁琐 
   @Value("${account.name}")
SpringBoot  @ConfigurationProperties