Spring

2020-09-05 本文已影响0人 __method__

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>

Spring

重点内容IoC和AOP

Spring

Dao

impl

bean.xml

service

Test

使用注解进行配置

@Component

@Controller @Service @Repository

@Autowired

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