Spring注解编程

　　Spring多文件配置处理
　　通配符方式# 非web环境 ApplicationContext ctx = new ClassPathXmlApplicationContext(＂/applicationContext-*.xml＂);  # web环境    	contextConfigLocation 		classpath:applicationContext-*.xml import标签# applicationContext.xml 整合其他配置内容     ...# 非web环境 ApplicationContext ctx = new ClassPathXmlApplicationContext(＂/applicationContext.xml＂);  # web环境    	contextConfigLocation 		classpath:applicationContext.xml 接口的契约性
　　注解的契约性
　　Spring的基础注解
　　在Spring框架应用注解时，如果对注解配置的内容不满意，可以通过Spring配置文件进行覆盖。对象创建相关注解
　　》》》搭建开发环境 
　　》》》对象相关注解
　　1）@Component : 替换原有Spring配置文件中bean标签显示指定工厂创建对象的id值：@Component(＂u＂)；
　　Spring配置文件覆盖注解配置内容：
　　2）@Component 的衍生注解以下三种注解能更加准确的表达一个类型的作用
　　@Repository ===》XXXDAO
　　@Service ===》XXXService
　　@Controller
　　注意：①本质上这些衍生注解就是@Component，作用、细节、用法完全一致
　　②Spring整合MyBatis开发过程中，不使用@Repository、@Component,原因是DAO的对象是动态代理创建的
　　3）@Scope : 控制简单对象创建次数
　　注意：不添加@Scope Spring提供默认值singleton
　　4) @Lazy ：延迟创建单实例对象
　　注意：使用@Lazy注解后，Spring使用这个对象的时候，才会进行对象的创建
　　5）生命周期相关注解
　　注入相关注解
　　》》》@Autowired ===> 用户自定义类型
　　① @Autowired基于类型进行注入：注入对象的类型，必须与目标成员变量类型相同或者是其子类（实现类）===> 推荐
　　② @Autowired @Qualifier 基于名字进行注入
　　③ @Autowired放置位置
　　a) 放置在对应成员变量的set方法上
　　b) 放置在成员变量之上，Spring通过反射直接对成员变量进行注入（赋值）===> 推荐
　　④JavaEE规范中类似功能的注解
　　JSR250 @Resource(name=＂userDAOImpl＂)基于名字进行注入
　　@Autowired()
　　@Qualifier(＂userDAOImpl＂)
　　注意：如果在应用Resource注解时，名字没有配对成功，那么会继续按照类型进行注入
　　JSR330 @Inject作用 @Autowired完全一致 基于类型进行注入 ===> EJB3.0   javax.inject   javax.inject   1 
　　》》》JDK类型
　　1）@Value注解①不能应用在静态成员变量上，否则赋值（注入）失败
　　②该注解+Properties这种方式，不能注入集合类型，YMAL/YML配置方式替代
　　2）@PropertySource
　　注解扫描# 当前包及其子包 
　　》》》排除方式
　　》》》包含方式
　　注解开发的思考
　　》》》配置互通
　　》》》注解和配置文件使用的条件程序员自己开发的类型，可以加入对应的注解，进行对象创建。
　　非程序员开发的类型，需要配置文件(bean标签来完成)进行配置。（如：SqlSessionFactoryBean、MapperScannerConfigure）SSM半注解DAO(Spring + MyBatis)
　　Service
　　ControllerSpring的高级注解配置Bean
　　@Configuration实际上是@Component的衍生注解
　　》》》配置日志
　　基于注解开发，不能集成log4j, 发现没有日志打印
　　基于注解开发，集成的是logback    org.slf4j   slf4j-api   1.7.25      org.slf4j   jcl-over-slf4j   1.7.25      ch.qos.logback   logback-classic   1.2.3      ch.qos.logback   logback-core   1.2.3      org.logback-extensions   logback-ext-spring   0.1.4  <?xml version=＂1.0＂ encoding=＂UTF-8＂ ?>                  					             %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n                                   AnnotationConfigApplicationContext
　　@Bean注解
　　等同于XML配置文件中bean标签
　　》》》对象的创建简单对象：直接通过new方式创建的对象
　　复杂对象：不能通过new方式创建的对象（如：Connection, SqlSessionFactory）
　　package com.demo;  import com.demo.bean.User; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;  import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException;  @Configuration public class AppConfig {      /**      * 简单对象      * @return      */     @Bean     public User user() {         return new User();     }      /**      * 复杂对象(推荐使用)      *     Connection不能直接通过new创建      * @return      */     @Bean     public Connection conn() {         Connection conn = null;         try {             Class.forName(＂com.mysql.cj.jdbc.Driver＂);             conn = DriverManager.getConnection(＂jdbc:mysql://192.168.XXX.222:3306/ssm_db?useSSL=false＂, ＂root＂, ＂root＂);         } catch (ClassNotFoundException e) {             e.printStackTrace();         } catch (SQLException throwables) {             throwables.printStackTrace();         }          return conn;     } }package com.demo.bean;  import org.springframework.beans.factory.FactoryBean;  import java.sql.Connection; import java.sql.DriverManager;  public class ConnectionFactoryBean implements FactoryBean {      @Override     public Connection getObject() throws Exception {         Class.forName(＂com.mysql.cj.jdbc.Driver＂);         Connection conn = DriverManager.getConnection(＂jdbc:mysql://192.168.XXX.222:3306/ssm_db?useSSL=false＂, ＂root＂, ＂root＂);          return conn;     }      @Override     public Class<?> getObjectType() {         return Connection.class;     }      @Override     public boolean isSingleton() {         return false;     } }/**      *  遗留系统使用该方式创建      *      很少自己写ConnectionFactoryBean，来创建复杂对象      * @return      */ @Bean public Connection conn() {     Connection conn = null;     try {         ConnectionFactoryBean factoryBean = new ConnectionFactoryBean();         conn = factoryBean.getObject();     } catch (Exception e) {         e.printStackTrace();     }      return conn; }
　　》》》自定义id值
　　@Bean(＂id＂)
　　》》》控制对象创建次数@Bean
　　@Scope(＂singleton|prototype＂) 默认值singleton@Bean注解的注入
　　》》》用户自定义注入package com.demo;  import com.demo.injection.UserDAO; import com.demo.injection.UserDAOImpl; import com.demo.injection.UserService; import com.demo.injection.UserServiceImpl; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;  @Configuration public class AppConfig {     @Bean     public UserDAO userDAO() {         return new UserDAOImpl();     }      @Bean     public UserService userService(UserDAO userDAO) {         UserServiceImpl userService = new UserServiceImpl();         userService.setUserDAO(userDAO);          return userService;     } }package com.demo;  import com.demo.injection.UserDAO; import com.demo.injection.UserDAOImpl; import com.demo.injection.UserService; import com.demo.injection.UserServiceImpl; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;  @Configuration public class AppConfig {     @Bean     public UserDAO userDAO() {         return new UserDAOImpl();     }    	// 简化写法（没有把userDAO作为形参传入）     @Bean     public UserService userService() {         UserServiceImpl userService = new UserServiceImpl();         userService.setUserDAO(userDAO());          return userService;     } }
　　》》》JDK类型注入@Bean public Customer customer() {     Customer customer = new Customer();     // 硬代码 耦合     customer.setId(1);     customer.setName(＂zhangsan＂);      return customer; }package com.demo;  import com.demo.bean.Customer; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.PropertySource;  /**  *  读取配置文件init.properties,解决耦合问题 */ @Configuration @PropertySource(＂classpath:init.properties＂) public class AppConfig {          @Value(＂${id}＂)     private Integer id;     @Value(＂${name}＂)     private String name;      @Bean     public Customer customer() {         Customer customer = new Customer();         customer.setId(id);         customer.setName(name);          return customer;     } } @ComponentScan注解@ComponentScan等同于XML配置文件中的标签
　　目的：扫描注解 （如：@Component、@Value、@Autowired ...）
　　》》》排除、包含的使用
　　1）排除
　　2）包含
　　Spring多种配置方式
　　》》》配置优先级配置文件bean标签 > @Bean > @Component及其衍生注解
　　优先级高的配置 覆盖 优先级低的配置
　　配置的优先级能解决耦合问题
　　ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig4.class, AppConfig5.class);  ApplicationContext ctx = new AnnotationConfigApplicationContext(＂com.demo.config＂);多个配置信息
　　》》》多配置信息整合
　　① 多个配置Bean的整合
　　1) base-package进行多个配置Bean的整合
　　2) @Import
　　1. 可以创建对象
　　2. 多配置bean的整合
　　3) 指定多个配置Bean的Class对象ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig1.class, AppConfig2.class,...);
　　② 配置Bean与@Component相关注解的整合
　　③ 配置Bean与Spring XML配置文件的整合
　　跨配置的注入
　　配置Bean底层实现原理
　　Spring在配置Bean中加入了@Configuration注解后，底层就会通过CGlib的代理方式，来进行对象相关的配置、处理四维一体的开发思想
　　基于schema
　　基于特定功能注解 ===> 推荐
　　基于原始      
　　基于@Bean注解 ===> 推荐package com.demo;  import org.springframework.context.annotation.*; import org.springframework.context.support.PropertySourcesPlaceholderConfigurer; import org.springframework.core.io.ClassPathResource;  @Configuration @ComponentScan(basePackages = ＂com.demo＂) public class AppConfig {      @Bean     public PropertySourcesPlaceholderConfigurer configurer() {         PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();         configurer.setLocation(new ClassPathResource(＂init.properties＂));          return configurer;     } }纯注解版AOP编程
　　package com.demo.aop;  public interface UserService {     void register();     void login(); }package com.demo.aop;  import org.springframework.stereotype.Service;  @Service public class UserServiceImpl implements UserService {     @Override     public void register() {         System.out.println(＂UserServiceImpl.register＂);     }      @Override     public void login() {         System.out.println(＂UserServiceImpl.login＂);     } }package com.demo.aop;  import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.springframework.stereotype.Component;  @Aspect @Component public class MyAspect {      @Pointcut(＂execution(* com.demo.aop..*.*(..))＂)     public void pointCut() {}      @Around(＂pointCut()＂)     public Object arroud(ProceedingJoinPoint joinPoint) throws Throwable {          System.out.println(＂-------Log-----------＂);          Object proceed = joinPoint.proceed();          return proceed;     } }package com.demo.aop;  import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.EnableAspectJAutoProxy;  @Configuration @ComponentScan(basePackages = ＂com.demo.aop＂) @EnableAspectJAutoProxy public class AOPConfig { }
　　》》》注解AOP细节分析Spring AOP 代理 默认：JDK
　　SpringBoot AOP 代理默认：CGlib
　　纯注解版Spring+MyBatis整合基础配置（配置Bean）
　　package com.demo.mybatis;  import com.alibaba.druid.pool.DruidDataSource; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.Resource; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import org.springframework.core.io.support.ResourcePatternResolver;  import javax.sql.DataSource; import java.io.IOException;  @Configuration @ComponentScan(basePackages = ＂com.demo.mybatis＂) @MapperScan(basePackages = ＂com.demo.mybatis＂) public class MyBatisAutoConfiguration {      @Bean     public DataSource dataSource() {         DruidDataSource dataSource = new DruidDataSource();         dataSource.setDriverClassName(＂com.mysql.cj.jdbc.Driver＂);         dataSource.setUrl(＂jdbc:mysql://192.168.30.222:3306/ssm_db＂);         dataSource.setUsername(＂root＂);         dataSource.setPassword(＂root＂);          return dataSource;     }      @Bean     public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource) {         SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();          sqlSessionFactoryBean.setDataSource(dataSource);         sqlSessionFactoryBean.setTypeAliasesPackage(＂com.demo.mybatis＂); //        sqlSessionFactoryBean.setMapperLocations(new ClassPathResource(＂UserDAOMapper.xml＂));         try {             ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();             Resource[] resources = resolver.getResources(＂com/demo/mapper/*Mapper.xml＂);             sqlSessionFactoryBean.setMapperLocations(resources);         } catch (IOException e) {             e.printStackTrace();         }          return sqlSessionFactoryBean;     } }配置Bean耦合问题mybatis.driverClassName=com.mysql.cj.jdbc.Driver mybatis.url=jdbc:mysql://192.168.XXX.222:3306/ssm_db mybatis.username=root mybatis.password=root mybatis.typeAliasesPackages=com.demo.mybatis mybatis.mapperLocations=com/demo/mapper/*Mapper.xmlpackage com.demo.mybatis;  import lombok.Data; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.PropertySource; import org.springframework.stereotype.Component;  @Data @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; }package com.demo.mybatis;  import com.alibaba.druid.pool.DruidDataSource; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.Resource; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import org.springframework.core.io.support.ResourcePatternResolver;  import javax.sql.DataSource; import java.io.IOException;  @Configuration @ComponentScan(basePackages = ＂com.demo.mybatis＂) @MapperScan(basePackages = ＂com.demo.mybatis＂) 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;     } }纯注解版事务编程
　　package com.demo.mybatis;  public interface UserService {     void register(User user); }package com.demo.mybatis;  import lombok.Data; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional;  @Data @Service @Transactional public class UserServiceImpl implements UserService {      @Autowired     private UserDAO userDAO;      @Override     public void register(User user) {         userDAO.save(user);     } }package com.demo.mybatis;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.jdbc.datasource.DataSourceTransactionManager; import org.springframework.transaction.annotation.EnableTransactionManagement;  import javax.sql.DataSource;  @Configuration @EnableTransactionManagement public class TransactionAutoConfiguration {      @Autowired     private DataSource dataSource;      @Bean     public DataSourceTransactionManager dataSourceTransactionManager() {         DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();         dataSourceTransactionManager.setDataSource(dataSource);          return dataSourceTransactionManager;     } }Spring中YAML/YML使用
　　YML语法
　　Spring与YML集成
　　   org.yaml   snakeyaml   2.0 
　　》》》init.ymlaccount:   name: zhangsan   password: rootpackage com.demo.yml;  import lombok.Data; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Component;  @Data @Component public class Account {     @Value(＂${account.name＂)     private String name;     @Value(＂${account.password}＂)     private String password; }package com.demo.yml;  import org.springframework.beans.factory.config.YamlPropertiesFactoryBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.support.PropertySourcesPlaceholderConfigurer; import org.springframework.core.io.ClassPathResource;  import java.util.Properties;  @Configuration @ComponentScan(basePackages = ＂com.demo.yml＂) public class YmlAutoConfiguration {      @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;     } }Spring与YML集成问题
　　》》》init.ymlaccount:   name: zhangsan   password: root list: 111,222package com.demo.yml;  import lombok.Data; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Component;  import java.util.List;  @Data @Component public class Account {     @Value(＂${account.name＂)     private String name;     @Value(＂${account.password}＂)     private String password;     @Value(＂#{＂${list}＂.split(＂,＂)}＂)     private List list; }