重点内容IoC和AOP
Spring
Spring是分层的 Java SE/EE应用 full-stack 轻量级开源框架，以 IoC（Inverse Of Control：反转控制）和 AOP（Aspect Oriented Programming：面向切面编程）为内核，提供了展现层 SpringMVC 和持久层 Spring JDBC 以及业务层事务管理等众多的企业级应用技术，还能整合开源世界众多著名的第三方框架和类库，逐渐成为使用最多的Java EE 企业应用开源框架
spring 的体系结构
编写XML 配置spring账户转账案例
实体类Account .java
package com.neusoft.domain;
import java.io.Serializable;
/**
* @author Eric Lee
* @date 2020/9/5 11:01
*/
public class Account implements Serializable {
private Integer id;
private String name;
private Float money;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Float getMoney() {
return money;
}
public void setMoney(Float money) {
this.money = money;
}
@Override
public String toString() {
return "Account{" +
"id=" + id +
", name='" + name + '\'' +
", money=" + money +
'}';
}
}
Dao
package com.neusoft.dao;
import com.neusoft.domain.Account;
import java.util.List;
public interface IAccountDao {
List<Account> findAllAccount();
Account findAccountById(Integer accountId);
void saveAccount(Account account);
void updateAccount(Account account);
void deleteAccount(Integer accountId);
}
impl
package com.neusoft.dao.Impl;
import com.neusoft.dao.IAccountDao;
import com.neusoft.domain.Account;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.sql.SQLException;
import java.util.List;
/**
* @author Eric Lee
* @date 2020/9/5 11:10
*/
public class AccountDaoImpl implements IAccountDao {
private QueryRunner runner;
public void setRunner(QueryRunner runner) {
this.runner = runner;
}
@Override
public List<Account> findAllAccount() {
try {
return runner.query("select * from account", new BeanListHandler<Account>(Account.class));
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public Account findAccountById(Integer accountId) {
try {
return runner.query("select * from account where id = ?", new BeanHandler<Account>(Account.class), accountId);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void saveAccount(Account account) {
try {
runner.update("insert into account(name,money) values (?, ?)",account.getName(), account.getMoney());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void updateAccount(Account account) {
try {
runner.update("update account set name= ? , money = ? where id=? ",account.getName(), account.getMoney(), account.getId());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void deleteAccount(Integer accountId) {
try {
runner.update("delete from account where id = ?", accountId);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
bean.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- 配置service-->
<bean id="accountService" class="com.neusoft.service.impl.AccountServiceImpl">
<property name="accountDao" ref="accountDao"></property>
</bean>
<!-- 配置dao-->
<bean id="accountDao" class="com.neusoft.dao.Impl.AccountDaoImpl">
<!-- 注入qr-->
<property name="runner" ref="runner"></property>
</bean>
<!-- 配置QueryRunner-->
<bean id="runner" class="org.apache.commons.dbutils.QueryRunner">
<!-- 注入数据源-->
<constructor-arg name="ds" ref="dataSource"></constructor-arg>
</bean>
<!-- 配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/java9_spring"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
</beans>
service
package com.neusoft.service;
import com.neusoft.domain.Account;
import java.util.List;
public interface IAccountService {
// 查询所有
List<Account> findAllAccount();
Account findAccountById(Integer accountId);
void saveAccount(Account account);
void updateAccount(Account account);
void deleteAccount(Integer accountId);
}
实现
package com.neusoft.service.impl;
import com.neusoft.dao.IAccountDao;
import com.neusoft.dao.Impl.AccountDaoImpl;
import com.neusoft.domain.Account;
import com.neusoft.service.IAccountService;
import java.util.List;
/**
* @author Eric Lee
* @date 2020/9/5 11:39
*/
public class AccountServiceImpl implements IAccountService {
private IAccountDao accountDao;
public void setAccountDao(IAccountDao accountDao) {
this.accountDao = accountDao;
}
@Override
public List<Account> findAllAccount() {
return accountDao.findAllAccount();
}
@Override
public Account findAccountById(Integer accountId) {
return accountDao.findAccountById(accountId);
}
@Override
public void saveAccount(Account account) {
accountDao.saveAccount(account);
}
@Override
public void updateAccount(Account account) {
accountDao.updateAccount(account);
}
@Override
public void deleteAccount(Integer accountId) {
accountDao.deleteAccount(accountId);
}
}
Test
package com.neusoft.test;
import com.neusoft.domain.Account;
import com.neusoft.service.IAccountService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.util.List;
/**
* @author Eric Lee
* @date 2020/9/5 14:09
*/
public class TestAccountService {
ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
IAccountService as = ac.getBean("accountService", IAccountService.class);
@Test
public void testFindAll() {
//3.执行方法
List<Account> accounts = as.findAllAccount();
for(Account account : accounts){
System.out.println(account);
}
}
@Test
public void testFindOne() {
//3.执行方法
Account account = as.findAccountById(1);
System.out.println(account);
}
@Test
public void testSave() {
Account account = new Account();
account.setName("test");
account.setMoney(12345f);
//3.执行方法
as.saveAccount(account);
}
@Test
public void testUpdate() {
//3.执行方法
Account account = as.findAccountById(4);
account.setMoney(23456f);
as.updateAccount(account);
}
@Test
public void testDelete() {
//3.执行方法
as.deleteAccount(4);
}
}
使用注解进行配置
bean.xml
<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.neusoft">
</context:component-scan>
<!-- 配置QueryRunner-->
<bean id="runner" class="org.apache.commons.dbutils.QueryRunner">
<!-- 注入数据源-->
<constructor-arg name="ds" ref="dataSource"></constructor-arg>
</bean>
<!-- 配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/java9_spring"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
</beans>
核心修改
将对象交给spring去管理， 指定扫描的包名
<context:component-scan base-package="com.neusoft">
</context:component-scan>
service层
dao层
@Component
- 作用
把资源让 spring 来管理。相当于在 xml 中配置一个 bean。 - 属性
value：指定 bean 的 id。如果不指定 value 属性，默认 bean 的 id 是当前类的类名。首字母小写。
@Controller @Service @Repository
他们三个注解都是针对一个的衍生注解，他们的作用及属性都是一模一样的。
他们只不过是提供了更加明确的语义化。
@Controller ：一般用于表现层的注解。
@Service ：一般用于业务层的注解。
@Repository ：一般用于持久层的注解
细节：如果注解中有且只有一个属性 要赋值时是 ，且名称是 value ，value 在赋值是可以不写
@Autowired
作用：自动按照类型注入。当使用注解注入属性时，set方法可以省略。它只能注入其他 bean 类型。当有多个类型匹配时，使用要注入的对象变量名称作为 bean 的 id，在 spring 容器查找，找到了也可以注入成功。找不到就报错。
相当于： <property name="accountDao" ref="accountDao"></property>
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