我爱Java系列---【使用 spring 的 IOC 的实现账户的 增删改查CRUD】

一、环境搭建

　　1.创建 maven 工程quickstart,并导入坐标

pom.xml 中的依赖：

<dependencies>

<!-- junit单元测试 -->

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
<!--spring整合测试类-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.0.2.RELEASE</version>
    </dependency>

<!-- spring框架 -->
    <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.0.2.RELEASE</version>
  </dependency>

<!-- dbutils

DBUtils封装了对JDBC的操作，简化了JDBC操作，可以少写代码。

org.apache.commons.dbutils

DbUtils 关闭链接等操作

QueryRunner 进行查询的操作

org.apache.commons.dbutils.handlers 处理结果集

 -->
　　<dependency>
      <groupId>commons-dbutils</groupId>
      <artifactId>commons-dbutils</artifactId>
      <version>1.4</version>
    </dependency>

<!-- mysql驱动-->
　　<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.26</version>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.9</version>
    </dependency>
  </dependencies>

2.创建数据库和编写实体类

//创建数据库
create table account
(
  id       int auto_increment primary key,
  name     varchar(32) ,
  password varchar(32),
  money    int         
);

//编写实体类
public class Account {

  private long id;
  private String name;
  private String password;
  private long money;


  public long getId() {
    return id;
  }

  public void setId(long id) {
    this.id = id;
  }


  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }


  public String getPassword() {
    return password;
  }

  public void setPassword(String password) {
    this.password = password;
  }


  public long getMoney() {
    return money;
  }

  public void setMoney(long money) {
    this.money = money;
  }

  @Override
  public String toString() {
    return "Account{" +
            "id=" + id +
            ", name='" + name + '\'' +
            ", password='" + password + '\'' +
            ", money=" + money +
            '}';
  }
}

3.编写持久层代码

//定义接口
public interface AccountDao {

    //1.增加账户
    public int save(Account account);

    //2.根据id查询账户
    public Account findById(int id);

}

//编写实现类
public  class AccountDaoImpl implements AccountDao {
    private QueryRunner queryRunner;

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

    //1.增加账户
    public int save(Account account){
        String sql ="insert into account values (null,?,?,?) ";
        try {
         return   queryRunner.update(sql,account.getName(),account.getPassword(),account.getMoney());
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    //2.根据id查询账户信息
    @Override
    public Account findById(int id) {
        String sql ="select * from account where id=?";
        try {
            return queryRunner.query(sql,new BeanHandler<>(Account.class),id);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}

4.编写业务层代码

//定义接口
public interface AccountService {

    //1.增加账户
    public int save(Account account);

    //2.根据id查询账户信息
    public Account findById(int id);
}

//编写实现类
public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;

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

    //1.增加账户
    @Override
    public int save(Account account) {

       return accountDao.save(account);
    }

    //2.根据id查询账户
    @Override
    public Account findById(int id) {
        return accountDao.findById(id);
    }
}

二、创建配置文件

1.创建配置文件并导入约束

<?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">

    <!--分析：service - dao - queryRunner - dateSource,从后往前配 -->

    <!--1.配置dateSource-->
    <bean id="dateSource" class="com.alibaba.druid.pool.DruidDataSource">

        <property name="url" value="jdbc:mysql:///heima?characterEncoding=utf-8"/>
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>

    </bean>

    <!--2.配置queryRunner-->
    <bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner">
        <constructor-arg name="ds" ref="dateSource"></constructor-arg>
    </bean>

    <!--3.配置AccountDao-->
    <bean id="accountDao" class="com.itheima.dao.impl.AccountDaoImpl">

        <property name="queryRunner" ref="queryRunner"/>
    </bean>

    <!--4.配置AccountService，并解决依赖注入-->
    <bean id="accountService" class="com.itheima.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
    
</beans>

三、测试代码

 

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations="classpath:beans.xml")
public class AccountTest {
    @Autowired
    private AccountService accountService;

//1.增加账户

@Test public void testSave() {
 Account account = new Account();
 account.setId(2); account.setName("亚瑟"); 
account.setPassword("yuji"); 
account.setMoney(3000);  
int i = accountService.save(account); 
if (i == 1) { System.out.println("添加账户成功"); } else { System.out.println("添加账户失败"); } }

 //2.根据id查询账户信息

@Test public void testFindById(){
  Account accountById = accountService.findById(2);
 System.out.println(accountById);
 } 
}

 

至此，增和查的功能已经完成，删改功能同理可得。