Spring04_IOC和DI实战

2020-05-25 16:08:06来源：博客园阅读 ()

Spring04_IOC和DI实战

本教程源码请访问：tutorial_demo

学习本篇教程之前，需要了解（会用就行）以下内容：

数据库连接池c3p0；

Apache Commons DbUtils。

只学习不练习一切都是假的，接下来我们利用之前学习的IOC和DI的知识结合Apache Commons DbUtils实现单表的CRUD操作。

一、需求和技术要求

1.1、需求

实现单表的CRUD

1.2、技术要求

使用Spring的IOC实现对象的管理；
使用Spring的DI实现属性的注入；
使用Apache Commons DbUtils进行持久层操作；
使用c3p0数据库连接池。

二、实现过程

2.1、建库建表

DROP DATABASE IF EXISTS springlearn;
CREATE DATABASE springlearn;
USE springlearn;


DROP TABLE IF EXISTS account;
CREATE TABLE account (
  id int(11) NOT NULL AUTO_INCREMENT,
  name varchar(40) DEFAULT NULL,
  money float DEFAULT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8mb4;

INSERT INTO account VALUES ('1', 'aaa', '1000');
INSERT INTO account VALUES ('2', 'bbb', '1000');
INSERT INTO account VALUES ('3', 'ccc', '1000');
INSERT INTO account VALUES ('5', 'cc', '10000');
INSERT INTO account VALUES ('6', 'abc', '10000');
INSERT INTO account VALUES ('7', 'abc', '10000');

2.2、创建Maven工程并添加相关坐标

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.codeaction</groupId>
    <artifactId>account</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

2.3、编写Account实体类

package org.codeaction.domain;

import java.io.Serializable;

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 +
                '}';
    }
}

2.4、编写持久层接口IAccountDao

package org.codeaction.dao;

import org.codeaction.domain.Account;

import java.util.List;

public interface IAccountDao {
    List<Account> findAll();
    Account findById(Integer id);
    void save(Account account);
    void update(Account account);
    void delete(Integer id);
}

2.5、编写持久层实现类IAccountDaoImpl

package org.codeaction.dao.impl;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.codeaction.dao.IAccountDao;
import org.codeaction.domain.Account;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import java.sql.SQLException;
import java.util.List;

public class AccountDaoImpl implements IAccountDao {
    private QueryRunner queryRunner;

    public void setQueryRunner(QueryRunner queryRunner) {
        this.queryRunner = queryRunner;
    }

    @Override
    public List<Account> findAll() {
        List<Account> list = null;
        try {
            list = queryRunner.query("select * from account", new BeanListHandler<Account>(Account.class));
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }

    @Override
    public Account findById(Integer id) {
        Account account = null;
        try {
            account = queryRunner.query("select * from account where id = ?",
                    new BeanHandler<Account>(Account.class), id);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return account;
    }

    @Override
    public void save(Account account) {
        Object[] params = {account.getName(), account.getMoney()};
        try {
            queryRunner.update("insert into account(name, money) values(?, ?)", params);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void update(Account account) {
        Object[] params = {account.getName(), account.getMoney(), account.getId()};
        try {
            queryRunner.update("update account set name=?, money=? where id=?", params);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void delete(Integer id) {
        Object[] params = {id};
        try {
            queryRunner.update("delete from account where id=?", id);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

2.6、编写业务层接口IAccountService

package org.codeaction.service;

import org.codeaction.domain.Account;

import java.util.List;

public interface IAccountService {
    List<Account> findAll();
    Account findById(Integer id);
    void save(Account account);
    void update(Account account);
    void delete(Integer id);
}

2.7、编写业务层实现类IAccountServiceImpl

package org.codeaction.service.impl;

import org.codeaction.dao.IAccountDao;
import org.codeaction.domain.Account;
import org.codeaction.service.IAccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

public class AccountServiceImpl implements IAccountService {
    private IAccountDao accountDao;

    public void setAccountDao(IAccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public List<Account> findAll() {
        return accountDao.findAll();
    }

    @Override
    public Account findById(Integer id) {
        return accountDao.findById(id);
    }

    @Override
    public void save(Account account) {
        accountDao.save(account);
    }

    @Override
    public void update(Account account) {
        accountDao.update(account);
    }

    @Override
    public void delete(Integer id) {
        accountDao.delete(id);
    }
}

2.8、编写XML配置文件（重点）

XML配置文件在resource目录下

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 配置service -->
    <bean id="accountService" class="org.codeaction.service.impl.AccountServiceImpl">
        <!-- 通过set方法注入dao实现类的对象 -->
        <property name="accountDao" ref="accountDao"></property>
    </bean>
    <!-- 配置dao -->
    <bean id="accountDao" class="org.codeaction.dao.impl.AccountDaoImpl">
        <!-- 通过set方法注入queryRunner实现类的对象 -->
        <property name="queryRunner" ref="queryRunner"></property>
    </bean>
    <!-- 配置queryRunner -->
    <bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype">
        <!-- 通过构造方法注入连接池 -->
        <constructor-arg name="ds" ref="dataSource"></constructor-arg>
    </bean>
    <!-- 配置连接池 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!-- 通过set方法注入四大参数 -->
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/springlearn"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
</beans>

Spring配置文件是这个项目的核心，同时也是通过这个配置文件的配置实现IOC和DI。结合前面的Java代码，bean的配置通过IOC的方式由Spring容器管理，属性通过DI的方式由Spring容器注入。

2.9、编写测试类

package org.codeaction.test;

import org.codeaction.domain.Account;
import org.codeaction.service.IAccountService;
import org.codeaction.service.impl.AccountServiceImpl;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

public class MyTest {
    private IAccountService accountService;
    @Before
    public void init() {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        accountService = context.getBean("accountService", AccountServiceImpl.class);
    }

    @Test
    public void testFindAll() {
        List<Account> accounts = accountService.findAll();
        for (Account account : accounts) {
            System.out.println(account);
        }
    }

    @Test
    public void testFindById() {
        Account account = accountService.findById(3);
        System.out.println(account);
    }

    @Test
    public void testSave() {
        Account account = new Account();
        account.setName("abc");
        account.setMoney(10000F);

        accountService.save(account);

        System.out.println(account);
    }

    @Test
    public void testDelete() {
        accountService.delete(4);
    }

    @Test
    public void testUpdate() {
        Account account = new Account();
        account.setId(5);
        account.setName("ab111111111c111");
        account.setMoney(10000F);
        accountService.update(account);
    }
}

分别运行测试方法进行测试。

原文链接:https://www.cnblogs.com/codeaction/p/12957614.html
如有疑问请与原作者联系

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