前言
在MyBatis學習-連接oracle實現CURD操作實現了MyBatis基本配置與CRUD操作。但是每次都是手工創建SqlSessionFactory本篇將通過spring來管理bean,同時使用Druid連接池替換自帶的連接池。
什么是Druid連接池
Druid是一個JDBC組件,它包括三部分:
- DruidDriver 代理Driver,能夠提供基於Filter-Chain模式的插件體系。
- DruidDataSource 高效可管理的數據庫連接池。
- SQLParser
Druid可以做什么?
- 可以監控數據庫訪問性能,Druid內置提供了一個功能強大的StatFilter插件,能夠詳細統計SQL的執行性能,這對於線上分析數據庫訪問性能有幫助。
- 替換DBCP和C3P0。Druid提供了一個高效、功能強大、可擴展性好的數據庫連接池。
- 數據庫密碼加密。直接把數據庫密碼寫在配置文件中,這是不好的行為,容易導致安全問題。DruidDruiver和DruidDataSource都支持PasswordCallback。
- SQL執行日志,Druid提供了不同的LogFilter,能夠支持Common-Logging、Log4j和JdkLog,你可以按需要選擇相應的LogFilter,監控你應用的數據庫訪問情況。
擴展JDBC,如果你要對JDBC層有編程的需求,可以通過Druid提供的Filter-Chain機制,很方便編寫JDBC層的擴展插件。
導入庫包
連接oracle
如果我們要連接oracle數據庫,需要導入oralce的jdbc的包。但是由於oracle收費, 因此maven沒有oracle庫包,需要我們自己手工導入外部包。或者也可以將oracle的jar導入到maven庫中。具體導入步驟可以查看Maven添加Oracle的依賴及驅動
<dependency>
<groupId>com.oracle.jdbc</groupId>
<artifactId>ojdbc6</artifactId>
<version>11.2.0.1.0</version>
</dependency>
連接mysql
由於mysql是免費的,我們可以通過maven直接安裝mysql的jdbc數據庫連接包
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.21</version>
</dependency>
導入mybatis
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
導入druid
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.11</version>
</dependency>
導入spring-jdbc包
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.8.RELEASE</version>
</dependency>
導入spring包
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.8.RELEASE</version>
</dependency>
導入spring事務相關包
<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>
導入mybatis-spring整合包
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.1</version>
</dependency>
配置
下面使用過mysql數據庫為例。
數據庫配置
在resources目錄下新建一個mysql.properities文件,用於配置連接數據庫的相關配置。
druid.url=jdbc:mysql://localhost:3306/mysql?serverTimezone=UTC
#這個可以缺省的,會根據url自動識別
druid.driverClassName=com.mysql.cj.jdbc.Driver
druid.username=root
druid.password=123456
##初始連接數,默認0
druid.initialSize=10
#最大連接數,默認8
druid.maxActive=30
#最小閑置數
druid.minIdle=10
#獲取連接的最大等待時間,單位毫秒
druid.maxWait=2000
#緩存PreparedStatement,默認false
druid.poolPreparedStatements=true
#緩存PreparedStatement的最大數量,默認-1(不緩存)。大於0時會自動開啟緩存PreparedStatement,所以可以省略上一句設置
druid.maxOpenPreparedStatements=20
druid配置
在resources目錄下新建一個applicationContext-mysql.xml文件,用於配置mysql的druid的數據庫連接池配置以及注入到spring的bean。
- 數據源的配置從mysql.propertie獲取的
<!--從mysql.properties加載配置-->
<context:property-placeholder location="classpath:mysql.properties" />
<!--druid連接池-->
<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>
- spring管理事務
<!--事務管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="druidDataSource"/>
</bean>
<!-- 使用annotation注解方式配置事務 -->
<tx:annotation-driven transaction-manager="transactionManager"/>
- 根據mapper生成代理
sqlSessionFactory需要注入數據源和配置文件路徑,spring會生成runoob_tblMapper
,我們通過這個值取bean就能對數據庫進行操作了。
<!-- 配置sqlSessionFactory,SqlSessionFactoryBean是用來產生sqlSessionFactory的 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--注入數據源-->
<property name="dataSource" ref="druidDataSource"/>
<property name="configLocation" value="classpath:conf.xml"/>
</bean>
<!-- MapperFactoryBean:根據mapper接口生成的代理對象 -->
<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連接池-->
<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>
<!--事務管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="druidDataSource"/>
</bean>
<!-- 使用annotation注解方式配置事務 -->
<tx:annotation-driven transaction-manager="transactionManager"/>
<!--mybatis工廠-->
<!-- 配置sqlSessionFactory,SqlSessionFactoryBean是用來產生sqlSessionFactory的 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--注入數據源-->
<property name="dataSource" ref="druidDataSource"/>
<property name="configLocation" value="classpath:conf.xml"/>
</bean>
<!-- MapperFactoryBean:根據mapper接口生成的代理對象 -->
<bean id="runoob_tblMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="mysql.dao.runoob_tblMapper"/>
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
- 添加conf.xml 配置映射的文件
<configuration>
<mappers>
<mapper resource="mapper/runoob_tblMapper.xml"></mapper>
</mappers>
</configuration>
- 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>
添加一個dto
在mysql.dto添加類
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;
}
}
在數據庫中添加表
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;
創建mapper
在mysql.dao添加runoob_tblMapper.java
這個接口名需要和runoob_tblMapper配置的命名空間一致
public interface runoob_tblMapper {
int insert(runoob_tbl tbl);
}
添加入庫的單元測試
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單元測試,插入一條記錄。
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());
}
}
}
通過MapperScannerConfigurer減少配置
通過上面配置,每個mapper都需要配置bean,若mapper比較多,配置的就很麻煩,可以通過MapperScannerConfigurer實現自動掃描,而無需配置mapper了
在sqlSessionFactory添加一個mapperLocations屬性,映射mapper下所有Mapper結尾的配置。
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--注入數據源-->
<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>
新增一個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>
添加單元測試
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());
}
}
}