MyBatis学习-使用Druid连接池将Maybatis整合到spring

前言

MyBatis学习-连接oracle实现CURD操作实现了MyBatis基本配置与CRUD操作。但是每次都是手工创建SqlSessionFactory本篇将通过spring来管理bean,同时使用Druid连接池替换自带的连接池。

什么是Druid连接池

Druid是一个JDBC组件,它包括三部分:

  • DruidDriver 代理Driver,能够提供基于Filter-Chain模式的插件体系。
  • DruidDataSource 高效可管理的数据库连接池。
  • SQLParser

Druid可以做什么?

  1. 可以监控数据库访问性能,Druid内置提供了一个功能强大的StatFilter插件,能够详细统计SQL的执行性能,这对于线上分析数据库访问性能有帮助。
  2. 替换DBCP和C3P0。Druid提供了一个高效、功能强大、可扩展性好的数据库连接池。
  3. 数据库密码加密。直接把数据库密码写在配置文件中,这是不好的行为,容易导致安全问题。DruidDruiver和DruidDataSource都支持PasswordCallback。
  4. SQL执行日志,Druid提供了不同的LogFilter,能够支持Common-Logging、Log4j和JdkLog,你可以按需要选择相应的LogFilter,监控你应用的数据库访问情况。

扩展JDBC,如果你要对JDBC层有编程的需求,可以通过Druid提供的Filter-Chain机制,很方便编写JDBC层的扩展插件。

导入库包

连接oracle

如果我们要连接oracle数据库,需要导入oralce的jdbc的包。但是由于oracle收费, 因此maven没有oracle库包,需要我们自己手工导入外部包。或者也可以将oracle的jar导入到maven库中。具体导入步骤可以查看Maven添加Oracle的依赖及驱动

<dependency>
  <groupId>com.oracle.jdbc</groupId>
  <artifactId>ojdbc6</artifactId>
  <version>11.2.0.1.0</version>
</dependency>

连接mysql

由于mysql是免费的,我们可以通过maven直接安装mysql的jdbc数据库连接包

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.21</version>
</dependency>

导入mybatis

<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.5.5</version>
</dependency>

导入druid

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.11</version>
</dependency>

导入spring-jdbc包

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>

导入spring包

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>

导入spring事务相关包

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>

导入mybatis-spring整合包


<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>1.3.1</version>
</dependency>

配置

下面使用过mysql数据库为例。

数据库配置

在resources目录下新建一个mysql.properities文件,用于配置连接数据库的相关配置。

druid.url=jdbc:mysql://localhost:3306/mysql?serverTimezone=UTC
#这个可以缺省的,会根据url自动识别
druid.driverClassName=com.mysql.cj.jdbc.Driver
druid.username=root
druid.password=123456

##初始连接数,默认0
druid.initialSize=10
#最大连接数,默认8
druid.maxActive=30
#最小闲置数
druid.minIdle=10
#获取连接的最大等待时间,单位毫秒
druid.maxWait=2000
#缓存PreparedStatement,默认false
druid.poolPreparedStatements=true
#缓存PreparedStatement的最大数量,默认-1(不缓存)。大于0时会自动开启缓存PreparedStatement,所以可以省略上一句设置
druid.maxOpenPreparedStatements=20

druid配置

在resources目录下新建一个applicationContext-mysql.xml文件,用于配置mysql的druid的数据库连接池配置以及注入到spring的bean。

  1. 数据源的配置从mysql.propertie获取的
  <!--从mysql.properties加载配置-->
    <context:property-placeholder location="classpath:mysql.properties" />
    <!--druid连接池-->
  <bean name="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
      <property name="url" value="${druid.url}" />
      <property name="driverClassName" value="${druid.driverClassName}" />
      <property name="username" value="${druid.username}" />
      <property name="password" value="${druid.password}" />
      <property name="initialSize" value="${druid.initialSize}"/>
      <property name="maxActive" value="${druid.maxActive}" />
      <property name="minIdle" value="${druid.minIdle}" />
      <property name="maxWait" value="${druid.maxWait}" />
      <property name="poolPreparedStatements" value="${druid.poolPreparedStatements}" />
      <property name="maxOpenPreparedStatements" value="${druid.maxOpenPreparedStatements}" />
  </bean>
  1. spring管理事务

<!--事务管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="druidDataSource"/>
</bean>
<!-- 使用annotation注解方式配置事务 -->
<tx:annotation-driven transaction-manager="transactionManager"/>
  1. 根据mapper生成代理

sqlSessionFactory需要注入数据源和配置文件路径,spring会生成runoob_tblMapper,我们通过这个值取bean就能对数据库进行操作了。


<!-- 配置sqlSessionFactory,SqlSessionFactoryBean是用来产生sqlSessionFactory的 -->

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!--注入数据源-->
    <property name="dataSource" ref="druidDataSource"/>
    <property name="configLocation" value="classpath:conf.xml"/>
</bean>

<!-- MapperFactoryBean:根据mapper接口生成的代理对象 -->

<bean id="runoob_tblMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="mapperInterface" value="mysql.dao.runoob_tblMapper"/>
    <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>

完整配置如下

<context:property-placeholder location="classpath:mysql.properties" />

  <!--druid连接池-->
<bean name="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
    <property name="url" value="${druid.url}" />
    <property name="driverClassName" value="${druid.driverClassName}" />
    <property name="username" value="${druid.username}" />
    <property name="password" value="${druid.password}" />
    <property name="initialSize" value="${druid.initialSize}"/>
    <property name="maxActive" value="${druid.maxActive}" />
    <property name="minIdle" value="${druid.minIdle}" />
    <property name="maxWait" value="${druid.maxWait}" />
    <property name="poolPreparedStatements" value="${druid.poolPreparedStatements}" />
    <property name="maxOpenPreparedStatements" value="${druid.maxOpenPreparedStatements}" />
</bean>

<!--事务管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="druidDataSource"/>
</bean>
<!-- 使用annotation注解方式配置事务 -->
<tx:annotation-driven transaction-manager="transactionManager"/>

<!--mybatis工厂-->

<!-- 配置sqlSessionFactory,SqlSessionFactoryBean是用来产生sqlSessionFactory的 -->

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!--注入数据源-->
    <property name="dataSource" ref="druidDataSource"/>
    <property name="configLocation" value="classpath:conf.xml"/>
</bean>

<!-- MapperFactoryBean:根据mapper接口生成的代理对象 -->

<bean id="runoob_tblMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="mapperInterface" value="mysql.dao.runoob_tblMapper"/>
    <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
  1. 添加conf.xml 配置映射的文件
<configuration>
    <mappers>
        <mapper resource="mapper/runoob_tblMapper.xml"></mapper>
    </mappers>
</configuration>

  1. 在resources/mapper下添加runoob_tblMapper.xml

<mapper namespace="mysql.dao.runoob_tblMapper">

   <insert id="insert" parameterType="mysql.dto.runoob_tbl" keyProperty="runoob_id" useGeneratedKeys="true">
    insert into runoob_tbl(runoob_title, runoob_author, submission_date) values(#{runoob_title},#{runoob_author},#{submission_date})
  </insert>
</mapper>

添加一个dto

在mysql.dto添加类


public class runoob_tbl {

    public  String runoob_id;
    public  String runoob_title;
    public  String runoob_author;
    public Date  submission_date;
    @Override
    public String toString() {
        return this.runoob_id + "," + this.runoob_title + "," + this.runoob_author + "," + this.submission_date;
    }

    public String getRunoob_id() {
        return runoob_id;
    }

    public void setRunoob_id(String runoob_id) {
        this.runoob_id = runoob_id;
    }

    public String getRunoob_title() {
        return runoob_title;
    }

    public void setRunoob_title(String runoob_title) {
        this.runoob_title = runoob_title;
    }

    public String getRunoob_author() {
        return runoob_author;
    }

    public void setRunoob_author(String runoob_author) {
        this.runoob_author = runoob_author;
    }

    public Date getSubmission_date() {
        return submission_date;
    }

    public void setSubmission_date(Date submission_date) {
        this.submission_date = submission_date;
    }
}

在数据库中添加表

create table runoob_tbl
(
    runoob_id int unsigned auto_increment primary key,
    runoob_title    varchar(100) not null,
    runoob_author   varchar(40)  not null,
    submission_date date null
)charset = utf8;

创建mapper

在mysql.dao添加runoob_tblMapper.java

这个接口名需要和runoob_tblMapper配置的命名空间一致


public interface runoob_tblMapper {
    int insert(runoob_tbl tbl);
}

添加入库的单元测试

需要在pom引入junit包

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>

添加ruidmybatistest单元测试,插入一条记录。


public class ruidmybatistest {

    @Test
    public void testGetUserList(){
        try
        {
            ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-mysql.xml");
            runoob_tblMapper mapper = ctx.getBean("runoob_tblMapper",runoob_tblMapper.class);
            runoob_tbl tbl = new runoob_tbl();
            tbl.setRunoob_author("jake");
            tbl.setRunoob_title("redis");
            tbl.setSubmission_date(new Date());
            int count =  mapper.insert(tbl);
            System.out.println(count);
        }catch (Exception exception)
        {
            System.out.println(exception.getMessage());
        }
    }

}

通过MapperScannerConfigurer减少配置

通过上面配置,每个mapper都需要配置bean,若mapper比较多,配置的就很麻烦,可以通过MapperScannerConfigurer实现自动扫描,而无需配置mapper了
在sqlSessionFactory添加一个mapperLocations属性,映射mapper下所有Mapper结尾的配置。

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!--注入数据源-->
    <property name="dataSource" ref="druidDataSource"/>
    <property name="configLocation" value="classpath:mapperConf.xml"/>
    <property name="mapperLocations" value="classpath:mapper/*Mapper.xml"/>
</bean>
<!--    <bean id="runoob_tblMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">-->
<!--        <property name="mapperInterface" value="mysql.dao.runoob_tblMapper"/>-->
<!--        <property name="sqlSessionFactory" ref="sqlSessionFactory" />-->
<!--    </bean>-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="mysql.dao" />
</bean>

新增一个student表

create table student
(
	name varchar(32) null,
	age int null,
	id int auto_increment,
	constraint student_pk
		primary key (id)
);

添加studentdto


public class student {

    public  String id;
    public  String name;
    public  int age;
    @Override
    public String toString() {
        return this.id + "," + this.name + "," + this.age;
    }

    public String getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

添加studentdao


public interface studentMapper {
    List<runoob_tbl>  selectByNames(List<String> name);
}

添加studentmapper.xml

在resources/mapper下添加studentmapper.xml


<mapper namespace="mysql.dao.studentMapper">

    <select id="selectByNames" resultType="mysql.dto.student">
          select * from student where name in
          <foreach item="name" index="index" collection="list" open="(" separator="," close=")">#{name}</foreach>
   </select>
</mapper>

添加单元测试


public class studenttest {

    @Test
    public void testGetList(){
        try
        {
            ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-mysql.xml");
            studentMapper mapper = ctx.getBean("studentMapper",studentMapper.class);
            List<Integer> ages=  new ArrayList<Integer>();
            ages.add(10);
            ages.add(20);
            List<student> blog = mapper.selectByAge(ages);
            for (student item : blog) {
                System.out.println(item);
            }
        }catch (Exception exception)
        {
            System.out.println(exception.getMessage());
        }
    }

}

参考文献

  1. Maven添加Oracle的依赖及驱动
posted @ 2020-08-17 18:21  杰哥很忙  阅读(1528)  评论(0编辑  收藏  举报