项目目录结构

1. 导入依赖

创建 maven 工程，除了 Spring 的基本依赖外，还需要导入 Mybatis 和 Druid 的相关依赖：

org.springframeworkgroupId>

spring-jdbcartifactId>

${spring-base-version}version>

dependency>

mysqlgroupId>

mysql-connector-javaartifactId>

8.0.13version>

dependency>

com.oraclegroupId>

ojdbc6artifactId>

11.2.0.3.0version>

dependency>

org.mybatisgroupId>

mybatis-springartifactId>

1.3.2version>

dependency>

org.mybatisgroupId>

mybatisartifactId>

3.4.6version>

dependency>

com.alibabagroupId>

druidartifactId>

1.1.12version>

dependency>

2. web.xml 配置

在 web.xml 中配置 Spring 的前端控制器以及 Druid 的 Web 监控台，用于获取数据库的相关监控信息：

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee

http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"

version="3.1">

springMvcservlet-name>

org.springframework.web.servlet.DispatcherServletservlet-class>

contextConfigLocationparam-name>

classpath:springApplication.xmlparam-value>

init-param>

1load-on-startup>

servlet>

springMvcservlet-name>

/url-pattern>

servlet-mapping>

DruidStatViewservlet-name>

com.alibaba.druid.support.http.StatViewServletservlet-class>

resetEnableparam-name>

trueparam-value>

init-param>

loginUsernameparam-name>

druidparam-value>

init-param>

loginPasswordparam-name>

druidparam-value>

init-param>

servlet>

DruidStatViewservlet-name>

/druid/*url-pattern>

servlet-mapping>

DruidWebStatFilterfilter-name>

com.alibaba.druid.support.http.WebStatFilterfilter-class>

exclusionsparam-name>

*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*param-value>

init-param>

filter>

DruidWebStatFilterfilter-name>

/*url-pattern>

filter-mapping>

web-app>

3. 数据库配置

在 resources 文件夹下新建数据库配置文件 jdbc.properties：

# mysql 数据库配置

mysql.url=jdbc:mysql://localhost:3306/mysql

mysql.username=root

mysql.password=root

# oracle 数据库配置

oracle.url=jdbc:oracle:thin:@//IP 地址:端口号/数据库实例名

oracle.username=用户名

oracle.password=密码

4. Druid 连接池配置

在 resources 文件夹下创建 springApplication.xml 配置文件和 druid.xml 配置文件：

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"

xmlns:mvc="http://www.springframework.org/schema/mvc"

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-4.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

bean>

bean>

class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

bean>

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-4.1.xsd">

bean>

beans>

5. MyBatis 配置

新建 mybtais 配置文件，按照需求配置额外参数， 更多 settings 配置项可以参考 官方文档

settings>

configuration>

6. 数据查询

新建查询接口及其实现类，以下示例分别查询的是 MySQL 和 Oracle 中的字典表：

public interface MysqlDao {

List get();

}

SELECT help_keyword_id AS id,name

FROM HELP_KEYWORD

WHERE HELP_KEYWORD_ID = #{id}

select>

mapper>

public interface OracleDao {

ListqueryById(long id);

}

select * from APEX_030200.WWV_FLOW_CALS where ID = #{id}

select>

mapper>

7. 测试查询

新建测试类进行测试：

@RestController

public class MysqlController {

@Autowired

private MysqlDao mysqlDao;

@GetMapping("relation/{id}")

public String get(@PathVariable(name = "id") String id) {

return mysqlDao.queryById(id).get(0).toString();

}

}

@RestController

public class OracleController {

@Autowired

private OracleDao oracleDao;

@GetMapping("flow/{id}")

public String get(@PathVariable(name = "id") Long id) {

return oracleDao.queryById(id).get(0).toString();

}

}

8. Druid 监控台

Druid Web 页面访问地址为：http://localhost:8080/druid/index.html ，可以登录后查看数据库相关监控数据：

源码GitHub地址：https://github.com/heibaiying/spring-samples-for-all