SpringBoot的dao层、JdbcTemplate多数据源访问实例

前言：

Spring boot集成mybatis大致过程如下：

（1）新建maven project，在pom.xml文件中引入相关依赖。
（2）配置文件application.yml（application.properties）
（3）编写pojo实体类
（4）编写Mapper接口
（5）编写Service类
（6）编写Controller类
（7）编写启动的主类

用JdbcTemplate就不必写Service类，但需要写个Configuration类中配置JdbcTemplate的bean实例。

一、项目目录结构

二、新建MVN项目

创建过程需要填写groupId和artifactId，这里都是springboottest。

三、pom.xml把依赖的库都填进去。内容如下：

<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>springboottest</groupId>
	<artifactId>springboottest</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>springboot-mybatis</name>
	<description>Demo project for Spring Boot</description>


	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.8.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.0</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>

四、创建数据库表user及配置：

见Spring Mybatis实例SqlSessionDaoSupport混用xml配置和注解。为了演示多数据源，分别在yiibai和test2中建user表，插入的数据内容不一样（随便写、只要两个不也一样就行）。

-- Database: `yiibai`
INSERT INTO `user` (`id`, `name`, `dept`, `website`, `phone`, `birthday`) VALUES
(1, 'yiibai1', 'Tech', 'http://www.yiibai.com', '13800009911', '1973-11-05'),
(2, '依依2', 'Tech', 'http://www.zjptcc.com', '13800009922', '1973-11-05'),
(3, 'yiibai3', 'Tech', 'http://www.zjptcc.com', '13800009900', '1973-11-05'),
(4, 'yiibai4', 'Tech', 'http://www.zjuni.com', '13800009900', '1973-11-05');


--
-- Database: `test2`
--
INSERT INTO `user` (`id`, `name`, `dept`, `website`, `phone`, `birthday`) VALUES
(1, 'yiibai1', 'Tech', 'http://www.yiibai.com', '13800009911', '1973-11-05'),
(2, '依蓓2', 'Tech', 'http://www.zjptcc.com', '13800009900', '1973-11-05'),
(3, '依蓓3', 'Tech', 'http://www.zjptcc.com', '13800009900', '1973-11-05'),
(4, '依依4', 'Tech', 'http://www.zjuni.com', '13800009900', '1973-11-05');

数据源的配置在MVN项目的application.yml中

spring:  
  datasource:  
    url : jdbc:mysql://localhost:3306/yiibai?useSSL=false  
    username : your-user  
    password : your-passwd  
    driver-class-name : com.mysql.jdbc.Driver
  test2ds:  
    url : jdbc:mysql://localhost:3306/test2?useSSL=false  
    username :  your-user 
    password : your-passwd  
    driver-class-name : com.mysql.jdbc.Driver

修改username和password以适应你的数据库环境

五、DAO层接口和实体类

和Spring Mybatis实例SqlSessionDaoSupport混用xml配置和注解中的例子类似。其中IUser加@Mapper
注释并去掉public User oneByID(int id);方法。修改后内容如下：

package com.yiibai.mybatis.dao;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.yiibai.mybatis.models.User;

@Mapper
public interface IUser {
    @Select("select * from user where id= #{id}")
    public User getUserByID(int id);
    
    @Insert("insert into user(id,name, dept,phone,website,birthday) values(#{id},#{name}, #{dept},#{phone}, #{website}, #{birthday})")
    public int insertUser(User user);
    
    @Delete("delete from user where id=#{id}")
    public int deleteUserById(int id);
    
    @Update("update user set name=#{name},dept=#{dept},phone=#{phone},website=#{website},birthday=#{birthday} where id=#{id}")
    public int updateUser(User user);
    
    @Select("select * from user")
    public List<User> getAllUser();

}

User类内容不变。加一个UserRowMapper类JdbcTemplate函数中使用，具体作用见Spring 的持久化实例中的三第2点中有详细说明。内容如下：

package com.yiibai.mybatis.models;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.RowMapper;

public class UserRowMapper implements RowMapper<User> {

	public User mapRow(ResultSet rs, int arg1) throws SQLException {
		// TODO 自动生成的方法存根
		return new User(rs.getInt("id"),rs.getString("name"),rs.getString("dept")
				,rs.getString("phone"),rs.getString("website"),rs.getDate("birthday"));
	}
}

六、Server类

package com.yiibai.mybatis.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.yiibai.mybatis.dao.IUser;
import com.yiibai.mybatis.models.User;

@Service(value="userService")
public class UserService {
	@Autowired
    private IUser iUser;
	public List<User> getAllUser() {
		// TODO 自动生成的方法存根
		return iUser.getAllUser();
	}
	
	public User getUserByID(int id) {
		// TODO 自动生成的方法存根
		return iUser.getUserByID(id);
	}
	
	public int deleteUserById(int id) {
		// TODO 自动生成的方法存根
		return iUser.deleteUserById(id);
	}

	public int updateUser(User user) {
		// TODO 自动生成的方法存根
		return iUser.updateUser(user);
	}
}

七、多数据源配置

package com.yiibai.mybatis.datasource;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.core.JdbcTemplate;

@Configuration
public class DataSourceConfig {
	@Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @ConfigurationProperties(prefix="spring.datasource")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @Primary
    @ConfigurationProperties(prefix="spring.test2ds")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "primaryJdbcTemplate")
    public JdbcTemplate primaryJdbcTemplate(
            @Qualifier("primaryDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

    @Bean(name = "secondaryJdbcTemplate")
    public JdbcTemplate secondaryJdbcTemplate(
            @Qualifier("secondaryDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

}

七、web控制类

这里实现了两个controller类，UserController注入了Service类实例、Ucontroller注入了JdbcTemplate类实例。代码如下：

package com.yiibai.mybatis.web;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.yiibai.mybatis.models.User;
import com.yiibai.mybatis.service.UserService;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    @Qualifier("userService")  // @Resource(name = "userService")
	private UserService userService;
    
    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public List<User> getUsers() {
        return userService.getAllUser();
    }
    
    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public User getUserByID(@PathVariable("id") int id) {
        return userService.getUserByID(id);
    }
}

其中 userService会使用默认数据源，也就是在DataSourceConfig中有@Primary注释的那个DataSource

也就是在application.yml中spring.test2ds（数据库test2）那个。

package com.yiibai.mybatis.web;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.yiibai.mybatis.models.User;
import com.yiibai.mybatis.models.UserRowMapper;

@RestController
@RequestMapping("/u")
public class Ucontroller {
	@Autowired
	@Qualifier("primaryJdbcTemplate")
	protected JdbcTemplate primaryJdbcTemplate;

	@Autowired
	@Qualifier("secondaryJdbcTemplate")
	protected JdbcTemplate secondaryJdbcTemplate;

	@RequestMapping(value = "/list", method = RequestMethod.GET)
	public List<User> getUsers() {
		String sql = "SELECT * FROM user";
		return primaryJdbcTemplate.query(sql, new UserRowMapper());
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.GET)
	public User getUserByID(@PathVariable("id") int id) {
		String sql= "SELECT * FROM user WHERE id =  '"+id+"' ";
		return secondaryJdbcTemplate.queryForObject(sql,new UserRowMapper());
	}
}

八、主类：


package com.yiibai.mybatis;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
import org.springframework.web.bind.annotation.RestController;


@SpringBootApplication
@RestController
public class SpringbootMutiDsApp  implements EmbeddedServletContainerCustomizer{

	public static void main(String[] args) {
		SpringApplication.run(SpringbootMutiDsApp.class, args);
	}

	public void customize(ConfigurableEmbeddedServletContainer container) {
		// TODO 自动生成的方法存根
		container.setPort(8080);
	}
}

九、运行：


  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.8.RELEASE)

2017-11-01 09:02:22.233  INFO 5972 --- [           main] com.yiibai.mybatis.SpringbootMutiDsApp   : Starting SpringbootMutiDsApp on mymotif-Vostro-14-5480 with PID 5972 (/home/mymotif/workspace/SpringBootTest/target/classes started by mymotif in /home/mymotif/workspace/SpringBootTest)
2017-11-01 09:02:22.314  INFO 5972 --- [           main] com.yiibai.mybatis.SpringbootMutiDsApp   : No active profile set, falling back to default profiles: default
2017-11-01 09:02:22.458  INFO 5972 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@56de5251: startup date [Wed Nov 01 09:02:22 CST 2017]; root of context hierarchy
2017-11-01 09:02:26.092  INFO 5972 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-11-01 09:02:26.140  INFO 5972 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2017-11-01 09:02:26.141  INFO 5972 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.23
2017-11-01 09:02:26.341  INFO 5972 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-11-01 09:02:26.341  INFO 5972 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 3895 ms
2017-11-01 09:02:26.509  INFO 5972 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-11-01 09:02:26.514  INFO 5972 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-11-01 09:02:26.514  INFO 5972 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-11-01 09:02:26.515  INFO 5972 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-11-01 09:02:26.515  INFO 5972 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-11-01 09:02:27.587  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@56de5251: startup date [Wed Nov 01 09:02:22 CST 2017]; root of context hierarchy
2017-11-01 09:02:27.676  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/u/{id}],methods=[GET]}" onto public com.yiibai.mybatis.models.User com.yiibai.mybatis.web.Ucontroller.getUserByID(int)
2017-11-01 09:02:27.678  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/u/list],methods=[GET]}" onto public java.util.List<com.yiibai.mybatis.models.User> com.yiibai.mybatis.web.Ucontroller.getUsers()
2017-11-01 09:02:27.679  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/{id}],methods=[GET]}" onto public com.yiibai.mybatis.models.User com.yiibai.mybatis.web.UserController.getUserByID(int)
2017-11-01 09:02:27.680  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/list],methods=[GET]}" onto public java.util.List<com.yiibai.mybatis.models.User> com.yiibai.mybatis.web.UserController.getUsers()
2017-11-01 09:02:27.685  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2017-11-01 09:02:27.685  INFO 5972 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2017-11-01 09:02:27.718  INFO 5972 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-11-01 09:02:27.719  INFO 5972 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-11-01 09:02:27.759  INFO 5972 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-11-01 09:02:28.045  INFO 5972 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-11-01 09:02:28.230  INFO 5972 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-11-01 09:02:28.235  INFO 5972 --- [           main] com.yiibai.mybatis.SpringbootMutiDsApp   : Started SpringbootMutiDsApp in 7.301 seconds (JVM running for 9.627)

http://localhost:8080/user/list

http://localhost:8080/u/list

这里可以看出http://localhost:8080/user/list获得的是test2库中的user表数据

而http://localhost:8080/u/list获得的是yiibai库中（通过primaryJdbcTemplate）的user表数据

十、也可以写个：Repository类注入JdbcTemplate类实例

package com.yiibai.mybatis.repositories;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import com.yiibai.mybatis.models.User;
import com.yiibai.mybatis.models.UserRowMapper;

@Repository
public class UserRepository {
    @Autowired
	@Qualifier("primaryJdbcTemplate")
    private JdbcTemplate jdbcTemplate;
    @Transactional(readOnly = true)
    public List<User> findAll() {
        return jdbcTemplate.query("select * from user", new UserRowMapper());
    }
    

    @Transactional(readOnly = true)
    public User findUserById(int id) {
        return jdbcTemplate.queryForObject("select * from user where id=?", new Object[]{id}, new UserRowMapper());
    }

}

这时控制类改为这样：

package com.yiibai.mybatis.web;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.yiibai.mybatis.models.User;
import com.yiibai.mybatis.repositories.UserRepository;

@RestController
@RequestMapping("/u")
public class Ucontroller {
    @Autowired
    private UserRepository userRepository;

	@RequestMapping(value = "/list", method = RequestMethod.GET)
	public List<User> getUsers() {
		return userRepository.findAll();
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.GET)
	public User getUserByID(@PathVariable("id") int id) {
		return userRepository.findUserById(id);
	}
}

参考：

SpringBoot多数据源的配置(SpringBoot+MyBatis)

Spring中jdbcTemplate的用法实例（一）

Springboot中使用mybatis连接mysql数据库

Spring Mybatis实例SqlSessionDaoSupport混用xml配置和注解

Spring 的持久化实例

Spring Boot中mybatis的使用

SpringBoot的dao层、JdbcTemplate多数据源访问实例

Spring中jdbcTemplate的用法实例（一）

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