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数据源配置参考：https://blog.csdn.net/const_/article/details/96977428

准备数据库表。

CREATE TABLE `user`  (  `id` int(32) NOT NULL AUTO_INCREMENT,  `user_name` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,  `password` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,  `real_name` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,  PRIMARY KEY (`id`) USING BTREE) ENGINE = InnoDB AUTO_INCREMENT = 32 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;INSERT INTO `user` VALUES (2, 'tom', '123', 'tomjames');INSERT INTO `user` VALUES (3, 'James', '123456', 'LenJames');

导入依赖

       
    
     mysql
        
    
     mysql-connector-java
        
        
    
     5.1.42
        
    
     runtime
    
   
       
    
     org.mybatis.spring.boot
        
    
     mybatis-spring-boot-starter
        
    
     2.0.1
    
   
   
       
    
     tk.mybatis
        
    
     mapper-spring-boot-starter
        
    
     2.0.2
    
   
   
       
    
     com.github.pagehelper
        
    
     pagehelper-spring-boot-starter
        
    
     1.2.5
    
   

MyBatis配置

1、application.yml

spring:  datasource:    driver-class-name: com.mysql.jdbc.Driver    url: jdbc:mysql://localhost:3306/test?autoReconnect=true&autoReconnectForPools=true&useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&useSSL=true    username: root    password: 123456mybatis:  # mapper配置文件路径  mapper-locations: classpath:mapper/*Mapper.xml  # 配置实体类包路径  type-aliases-package: com.example.demo.entity  configuration:    # 开启自动驼峰    map-underscore-to-camel-case: true    # 设置生成的主键值会被回显到插入对象中    use-generated-keys: true# 通用Mappermapper:  # 设置以后，会去判断 insert 和 update 中符串类型!=’’  not-empty: true  # 枚举按简单类型处理，如果有枚举字段则需要加上该配置才会做映射  enum-as-simple-type: truelogging:  level:    # 打印sql语句    com.example.demo.mapper: debug

2、SpringBoot 启动类

@SpringBootApplication// 扫描mapper接口路径//如果使用通用Mapper，应该导入import tk.mybatis.spring.annotation.MapperScan这个包@MapperScan("com.example.demo.mapper")public class SpringbootStudyApplication {
   	public static void main(String[] args) {
   		SpringApplication.run(SpringbootStudyApplication.class, args);	}}

3、UserMapper.java

@Mapperpublic interface UserMapper extends BaseMapper
   
    {
       User Sel(int id);}
   

4、UserMapper.xml

   
       
            
             
             
             
         
            
    
           id, user_name, password, real_name    
        
            select  from t_user where id=#{id}            
    
             insert into t_user (id, user_name, password,        real_name)        values (#{id,jdbcType=INTEGER}, #{userName,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},        #{realName,jdbcType=VARCHAR})    
    
   

使用Java文件配置方式和Druid数据源

项目整体目录结构。

1、导入依赖

2、数据库信息配置

在resources目录下创建 jdbc2.properties 配置文件。

jdbc.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8jdbc.username=rootjdbc.password=123456jdbc.initialSize=5jdbc.maxActive=5jdbc.maxIdle=5jdbc.minIdle=1jdbc.maxWait=6000jdbc.validationQuery=SELECT 1 FROM DUAL

3、数据源配置

实体类包路径修改成自己的实体类包路径。

import com.alibaba.druid.pool.DruidDataSource;import lombok.Getter;import lombok.Setter;import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.PropertySource;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import javax.sql.DataSource;@Configuration@PropertySource(value = "classpath:jdbc2.properties")@ConfigurationProperties(prefix = "jdbc")@Getter@Setterpublic class DruidConfig {
       private String url;    private String username;    private String password;    private Integer initialSize;    private Integer maxActive;    private String maxIdle;    private String minIdle;    private Long maxWait;    private String validationQuery;    @Bean    public DataSource druidDataSource() {
           DruidDataSource dataSource = new DruidDataSource();        dataSource.setUrl(url);        dataSource.setUsername(username);        dataSource.setPassword(password);        dataSource.setInitialSize(initialSize);        dataSource.setMaxActive(maxActive);        dataSource.setMaxWait(maxWait);        dataSource.setTimeBetweenEvictionRunsMillis(60000);        dataSource.setMinEvictableIdleTimeMillis(300000);        dataSource.setValidationQuery(validationQuery);        dataSource.setTestWhileIdle(true);        dataSource.setTestOnBorrow(false);        dataSource.setTestOnReturn(false);        dataSource.setPoolPreparedStatements(true);        return dataSource;    }    @Bean(name = "sqlSessionFactory")    public SqlSessionFactory sqlSessionFactory() throws Exception{
           SqlSessionFactoryBean factory = new SqlSessionFactoryBean();        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();        factory.setDataSource(druidDataSource());        // 每张表对应的xml文件        factory.setMapperLocations(resolver.getResources(("classpath:mapper/*Mapper.xml")));        // 每一张表对应的实体类        factory.setTypeAliasesPackage("com.example.Entity");		/*        // mybatis配置文件的位置        // factory.setConfigLocation(resolver.getResource(("classpath:mybatis/mybatis-config.xml")));		*/        org.apache.ibatis.session.Configuration configuration = factory.getObject().getConfiguration();        // 开启自动驼峰-下划线命名规则,默认false: Table(create_time) -> Entity(createTime)        configuration.setMapUnderscoreToCamelCase(true);        return factory.getObject();    }}

Mapper扫描包路径修改成自己的mapper接口包路径。

import org.mybatis.spring.mapper.MapperScannerConfigurer;import org.springframework.boot.autoconfigure.AutoConfigureAfter;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;@Configuration// 注意，由于MapperScannerConfigurer执行的比较早，所以必须有下面的注解@AutoConfigureAfter(DruidConfig.class)public class MyBatisMapperScannerConfig {
       @Bean    public MapperScannerConfigurer mapperScannerConfigurer() {
           MapperScannerConfigurer mapperScanner = new MapperScannerConfigurer();        mapperScanner.setSqlSessionFactoryBeanName("sqlSessionFactory");        mapperScanner.setBasePackage("com.example.mapper");        return mapperScanner;    }}

4、创建entity实体、mapper接口

通用Mapper采用了JPA规范包中的注解。 实体：

import lombok.AllArgsConstructor;import lombok.Data;import lombok.NoArgsConstructor;@Data@NoArgsConstructor@AllArgsConstructor@Table(name = "user")public class User {
   	@Id	@GeneratedValue(strategy = GenerationType.IDENTITY)    private Integer id;    private String userName;    private String passWord;    private String realName;}

Mapper：

import com.example.demo.Entity.User;public interface UserMapper{
       public User selectById(Long id);    public Long insert(User user);}

5、编写Mapper配置文件

在resources创建mapper文件夹，并创建UserMapper.xml配置文件。 namespace修改成自己对应的Mapper接口类全路径名。 配置文件中的实体类只写了实体类名，因为在配置数据源的时候，配置了实体类别名的包路径。

   
       
            
             
             
             
         
            
            select * from user where id = #{id}        
    
             insert into user          (user_name, password, real_name)        values          (#{userName}, #{passWord}, #{realName})    
    
   

6、编写控制器

import com.example.mapper.UserMapper;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;@Controller@RequestMapping("/")public class UserController {
       @Autowired    UserMapper userMapper;    @GetMapping("/user")    @ResponseBody    public String demo() {
           return userMapper.selectById(2L).toString();    }}

8、访问测试

MyBatis多数据源

导入依赖

       
    
     org.mybatis.spring.boot
        
    
     mybatis-spring-boot-starter
        
    
     2.0.0
    
   
       
    
     com.alibaba
        
    
     druid-spring-boot-starter
        
    
     1.1.17
    
   
       
    
     mysql
        
    
     mysql-connector-java
        
    
     5.1.28
        
    
     runtime
    
   

多数据源application.properties中的配置

spring.datasource.one.url=jdbc:mysql://localhost:3306/test01?useUnicode=true&characterEncoding=utf-8spring.datasource.one.username=rootspring.datasource.one.password=123456spring.datasource.one.type=com.alibaba.druid.pool.DruidDataSourcespring.datasource.two.url=jdbc:mysql://localhost:3306/test02?useUnicode=true&characterEncoding=utf-8spring.datasource.two.username=rootspring.datasource.two.password=123456spring.datasource.two.type=com.alibaba.druid.pool.DruidDataSource

提供两个DataSource

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import javax.sql.DataSource;@Configurationpublic class DataSourceConfig {
       @Bean    @ConfigurationProperties(prefix = "spring.datasource.one")    DataSource dsOne() {
           return DruidDataSourceBuilder.create().build();    }    @Bean    @ConfigurationProperties(prefix = "spring.datasource.two")    DataSource dsTwo() {
           return DruidDataSourceBuilder.create().build();    }}

MyBatis配置（两个数据源在两个类中分开来配置）

第一个数据源配置

import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.mybatis.spring.SqlSessionTemplate;import org.mybatis.spring.annotation.MapperScan;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import javax.annotation.Resource;import javax.sql.DataSource;@Configuration@MapperScan(basePackages = "com.demo.mapper1",        sqlSessionFactoryRef = "sqlSessionFactory1",        sqlSessionTemplateRef = "sqlSessionTemplate1")public class MyBatisConfigOne {
       @Resource(name = "dsOne")    DataSource dsOne;    @Bean    SqlSessionFactory sqlSessionFactory1() {
           SqlSessionFactory sessionFactory = null;        try {
               SqlSessionFactoryBean bean = new SqlSessionFactoryBean();            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();            bean.setDataSource(dsOne);            // 每张表对应的xml文件            bean.setMapperLocations(resolver.getResources(("classpath:mapper/*Mapper.xml")));            // 每一张表对应的实体类            bean.setTypeAliasesPackage("com.demo.entity");            sessionFactory = bean.getObject();        } catch (Exception e) {
               e.printStackTrace();        }        return sessionFactory;    }    @Bean    SqlSessionTemplate sqlSessionTemplate1() {
           return new SqlSessionTemplate(sqlSessionFactory1());    }}

第二个数据源配置

import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.mybatis.spring.SqlSessionTemplate;import org.mybatis.spring.annotation.MapperScan;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import javax.annotation.Resource;import javax.sql.DataSource;@Configuration@MapperScan(basePackages = "com.demo.mapper2",        sqlSessionFactoryRef = "sqlSessionFactory2",        sqlSessionTemplateRef = "sqlSessionTemplate2")public class MyBatisConfigTwo {
       @Resource(name = "dsTwo")    DataSource dsTwo;    @Bean    SqlSessionFactory sqlSessionFactory2() {
           SqlSessionFactory sessionFactory = null;        try {
               SqlSessionFactoryBean bean = new SqlSessionFactoryBean();            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();            bean.setDataSource(dsTwo);            // 每张表对应的xml文件            bean.setMapperLocations(resolver.getResources(("classpath:mapper/*Mapper.xml")));            // 每一张表对应的实体类            bean.setTypeAliasesPackage("com.demo.entity");            sessionFactory = bean.getObject();        } catch (Exception e) {
               e.printStackTrace();        }        return sessionFactory;    }    @Bean    SqlSessionTemplate sqlSessionTemplate2() {
           return new SqlSessionTemplate(sqlSessionFactory2());    }}

mapper和实体类创建

@Datapublic class User {
       private int id;    private String name;}public interface UserMapperOne {
       List
   
     getAllUser();}public interface UserMapperTwo {
       List
    
      getAllUser();}
    
   

mapper对应的XML配置

   
       
            select * from user;    
   

   
       
            select * from user;    
   

最后，在Service中注入两个不同的Mapper，不同的Mapper将操作不同的数据源。

参考：