Spring
IOC
通过IOC容器创建对象步骤
(1)创建Maven项目,导入依赖
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
(2)定义类
public class Student {
private String name;
private int age;
}
(3)注册bean
<bean id="student" class="com.cskaoyan.Student"/>
(4)获取对象
属性赋值
XML
(1)通过Set方法给属性赋值
基本数据类型
<bean id="student" class="com.cskaoyan.Student">
<property name="name" value="xyz"/>
<property name="age" value="18"/>
</bean>
引用数据类型
<bean id="student" class="com.cskaoyan.Student">
<property name="name" value="xyz"/>
<property name="age" value="18"/>
<property name="address" ref="address"/>
</bean>
<bean id="address" class="com.cskaoyan.Address">
<property name="province" value="广东省"/>
<property name="city" value="广州市"/>
</bean>
(2)通过构造方法赋值
定义类
@Data
public class Address {
private String province;
private String city;
public Address(String province, String city){
this.province = province;
this.city = city;
}
}
通过构造方法给对象赋值
<bean id="address" class="com.cskaoyan.Address">
<constructor-arg name="province" value="广东省"></constructor-arg>
<constructor-arg name="city" value="广州市"></constructor-arg>
</bean>
自动赋值方式
byName
属性名与bean的id值相同
<bean id="student" class="com.cskaoyan.Student" autowire="byName">
<property name="name" value="xyz"/>
<property name="age" value="18"/>
</bean>
<bean id="address" class="com.cskaoyan.Address">
<constructor-arg name="province" value="广东省"></constructor-arg>
<constructor-arg name="city" value="广州市"></constructor-arg>
</bean>
byType
属性类型与bean的类型相同
<bean id="student" class="com.cskaoyan.Student" autowire="byType">
<property name="name" value="xyz"/>
<property name="age" value="18"/>
</bean>
<bean id="address" class="com.cskaoyan.Address">
<constructor-arg name="province" value="广东省"></constructor-arg>
<constructor-arg name="city" value="广州市"></constructor-arg>
</bean>
注解
定义类
Student
@Component(value = "student")
@Data
public class Student {
@Value("xyz")
private String name;
@Value("20")
private int age;
@Autowired
private Address address;
}
Address
@Component(value = "address")
public class Address {
@Value("广东省")
private String province;
@Value("广州市")
private String city;
}
注册扫描器
<!--组件扫描器-->
<context:component-scan base-package="com.cskaoyan"/>
AOP
AOP的底层实现就是动态代理
AspectJ是一个AOP框架
使用步骤
(1)新建Maven项目,导入依赖
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
(2)添加AOP约束文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation=
"http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">
(3)定义接口及其实现类
UserService
public interface UserService {
User selectUserById(int id);
}
UserServiceImpl
@Component
public class UserServiceImpl implements UserService {
@Override
public User selectUserById(int id) {
// 业务主体逻辑
System.out.println("根据用户id查找用户");
return null;
}
}
(4)注册Aspect组件
@Aspect
@Component
public class MyAspect {
// 定义增强方法
@Before("execution(* com.cskaoyan.service.Impl.UserServiceImpl.*(..))")
public void doLog(){
System.out.println("日志记录...");
}
}
(5)设置组件扫描器以及AspectJ自动生成代理
<!--组件扫描器-->
<context:component-scan base-package="com.cskaoyan"/>
<!--AspectJ自动生成代理对象-->
<aop:aspectj-autoproxy/>
AspectJ事务管理
AOP面向切面编程事务管理
配置如下
<!--datasource-->
<bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/test"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="datasource"/>
</bean>
<!--事务设置-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="transfer" rollback-for="java.lang.Exception"/>
</tx:attributes>
</tx:advice>
<!--切入点-->
<aop:config>
<aop:pointcut id="transactionPointcut" expression="execution(* com.cskaoyan.service..*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="transactionPointcut"/>
</aop:config>
Spring事务管理
声明式事务管理
(1)配置事务管理器
<!--事务管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="datasource"/>
</bean>
<!--使用注解声明事务-->
<tx:annotation-driven transaction-manager="transactionManager"/>
(2)在Service层所在事务方法添加注解
@Transactional
@Override
public void transfer(Integer fromId, Integer toId, Integer money) {
// 主体业务逻辑
// 获取余额
Integer sourceAccountBalance = accountMapper.selectBalanceById(fromId);
Integer targetAccountBalance = accountMapper.selectBalanceById(toId);
// 完成转账
sourceAccountBalance -= money;
targetAccountBalance += money;
// 更新账户余额
accountMapper.updateAccountBalance(fromId, sourceAccountBalance);
// 模拟异常情况
System.out.println(1 / 0);
accountMapper.updateAccountBalance(toId, targetAccountBalance);
}
Spring整合Mybatis
(1)新建Maven项目,导入依赖
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.15.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.8</version>
</dependency>
</dependencies>
(2)配置文件
<!--datasource-->
<bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/test"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--sqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource"/>
</bean>
<!--dao-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.cskaoyan.mapper"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
(3)Dao层
AccountDao
public interface AccountDao {
Integer selectBalanceById(Integer id);
int updateAccountBalance(@Param("id") Integer id, @Param("money") Integer money);
}
(4)Service层
AccountService
public interface AccountService {
void transfer(Integer fromId, Integer toId, Integer money);
}
AccountServiceImpl
@Component
public class AccountServiceImpl implements AccountService {
@Autowired
@Qualifier("accountMapper")
AccountMapper accountMapper;
@Override
public void transfer(Integer fromId, Integer toId, Integer money) {
// 主体业务逻辑
// 获取余额
Integer sourceAccountBalance = accountMapper.selectBalanceById(fromId);
Integer targetAccountBalance = accountMapper.selectBalanceById(toId);
// 完成转账
sourceAccountBalance -= money;
targetAccountBalance += money;
// 更新账户余额
accountMapper.updateAccountBalance(fromId, sourceAccountBalance);
accountMapper.updateAccountBalance(toId, targetAccountBalance);
}
}
(5)测试
// Spring容器
ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
// 获取组件
AccountService accountService = (AccountService) app.getBean("accountServiceImpl");
// 转账
accountService.transfer(1, 2, 1000);