springboot multi-database and distributed transaction configuration

1. Import the corresponding jar package dependencies

<!-- Integrate mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<!-- Distributed Transaction Management-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jta-atomikos</artifactId>
</dependency>

2. Configure multiple data sources

　　2.1 Configure the connection of multiple data sources in application.xml

spring:
 datasource:
  test1:
   url: jdbc:mysql://localhost:3306/test
   username: root
   password: root
   driver-class-name: com.mysql.jdbc.Driver
   testQuery: select 1
  test2:
   url: jdbc:mysql://localhost:3306/test1
   username: root
   password: root
   driver-class-name: com.mysql.jdbc.Driver
   testQuery: select 1
mybatis:
  mapper-locations: classpath:mapping/*.xml 

　　2.2 Create a connection information configuration class for multiple databases

@ConfigurationProperties(prefix="spring.datasource.test1")
@Primary
public  class DB1Config {
    
    private String url;
    
    private String username;
    
    private String password;
    
    private String testQuery;

    public String getUrl() {
        return url;
    }

　　...add get and set methods, if multiple data sources are to be configured with multiple 

}

　　2.3 Create a configuration class for multiple data sources, and hand over different data sources to atomikos of jta for unified management (multiple data sources are configured with multiple such files)

@Configuration // Register in the spring boot container 
@MapperScan(basePackages="com.beifeng.hadoop.spring.boot.dao.jta.test1",sqlSessionFactoryRef="jtaTest1SqlSessionFactory" )
 public  class JtaDataSource1Config {

    @Bean(name="jtaTest1DataSource")
    @Primary//Only one data source is designated as the main data source in a project
    public DataSource testDataSource(DB1Config db1Config){
        MysqlXADataSource dataSource=new MysqlXADataSource();
        dataSource.setUrl(db1Config.getUrl());
        dataSource.setUser(db1Config.getUsername());
        dataSource.setPassword(db1Config.getPassword());
        dataSource.setPinGlobalTxToPhysicalConnection(true);
        //Call the data source an atomikos for unified management
        AtomikosDataSourceBean atomikosDataSource = new AtomikosDataSourceBean ();
        atomikosDataSource.setXaDataSource (dataSource);
        atomikosDataSource.setUniqueResourceName("jtaTest1DataSource");
        atomikosDataSource.setTestQuery (db1Config.getTestQuery ());
        return atomikosDataSource;
    }
    
    @Bean(name="jtaTest1SqlSessionFactory")
    @Primary
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("jtaTest1DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean=new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }
    
    @Bean(name="jtaTest1SqlSessionTemplate")
    @Primary
    public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("jtaTest1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

　　2.4 Declarative transaction configuration in service

@Service
public class Test1JtaUserService {
    
    @Autowired//Introduce different data sources
    private JtaUser1Dao jtaUser1Dao;
    
    @Autowired
    private JtaUser2Dao jtaUser2Dao;
    
    @Transactional//Declarative transaction
    public void insertJtaUser(String name,Integer age) {
        jtaUser1Dao.insertUser(name, age);
        jtaUser2Dao.insertUser(name, age);
        int a=1/0 ;//If an exception occurs, the distributed transaction will be rolled back at the same time
    }
    
}

　　2.5 Declare the configuration of multiple data sources in the startup class

@SpringBootApplication
@MapperScan( "com.beifeng.hadoop.spring.boot.dao" )//Specify the dao scan package path of mybatis
@EnableConfigurationProperties(value ={DB1Config.class , DB2Config.class } )//Specify the configuration of multiple data sources
 public  class App {
    
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

3 aop aspect programming

@Aspect
@Component
public class WebLogAspect {

    private Logger logger=LoggerFactory.getLogger(WebLogAspect.class);
    
    private Long startTime;
    
    @Pointcut("execution(public * com.beifeng.hadoop.spring.boot.controller..*.*(..))")
    public void webLog() {
        
    }
    
    @Before("webLog()")
    public void doBefore(JoinPoint joinPoint) {
        logger.info( "==============Start request=============" );
        startTime = System.currentTimeMillis(); 
         // Receive the request, record the request content 
        ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest httpServletRequest=requestAttributes.getRequest();
        logger.info("url:   "+httpServletRequest.getRequestURL());
        logger.info("http_method:    "+httpServletRequest.getMethod());
        logger.info("ip    "+httpServletRequest.getRemoteAddr());
        Enumeration<String> parameterNames = httpServletRequest.getParameterNames();
        while (parameterNames.hasMoreElements()) {
            String parameterName = (String) parameterNames.nextElement();
            logger.info("parameter:{}->{}",parameterName,httpServletRequest.getParameter(parameterName));
        }
    }
    
    @AfterReturning(returning ="ret",pointcut="webLog()" )
     public  void doAfterReturning(Object ret) {
         // After processing the request, return the content 
        logger.info("response result: "+ ret);
        logger.info( "==============Start and end, time-consuming"+(System.currentTimeMillis()-startTime)+"milliseconds============ =" );
        
    }
}