分散式事務解決方案的問題，

分散式事務產生的原因：

  多個不同的服務連線不同的資料來源 ，做分散式事務的管理。

這種情況是連線兩個資料來源的情況，然後事務管理器是這樣的 只管理了test02的這端業務程式碼。所以test02的這個會回滾！

但是test01會入庫哦

這屬於傳統的分散式事務解決方案

   使用springboot+jta+atomikos 分散式事物管理 （不適合微服務，需要拿到資料來源然後註冊到同一個全域性事務裡面去）

好了廢話不多說，動手擼程式碼！

引入的jar：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jta-atomikos</artifactId>
</dependency>

配置檔案也要修改：

application.properties：

# Mysql 1
mysql.datasource.test1.url = jdbc:mysql://localhost:3306/test01?useUnicode=true&characterEncoding=utf-8
mysql.datasource.test1.username = root
mysql.datasource.test1.password = root

mysql.datasource.test1.minPoolSize = 3
mysql.datasource.test1.maxPoolSize = 25
mysql.datasource.test1.maxLifetime = 20000
mysql.datasource.test1.borrowConnectionTimeout = 30
mysql.datasource.test1.loginTimeout = 30
mysql.datasource.test1.maintenanceInterval = 60
mysql.datasource.test1.maxIdleTime = 60



# Mysql 2
mysql.datasource.test2.url =jdbc:mysql://localhost:3306/test02?useUnicode=true&characterEncoding=utf-8
mysql.datasource.test2.username =root
mysql.datasource.test2.password =root

mysql.datasource.test2.minPoolSize = 3
mysql.datasource.test2.maxPoolSize = 25
mysql.datasource.test2.maxLifetime = 20000
mysql.datasource.test2.borrowConnectionTimeout = 30
mysql.datasource.test2.loginTimeout = 30
mysql.datasource.test2.maintenanceInterval = 60
mysql.datasource.test2.maxIdleTime = 60

　然後建立包：com.toov5.configure

 底層原理是使用的2PC

package com.toov5.configure;

import org.springframework.boot.context.properties.ConfigurationProperties;

import lombok.Data;

@Data
@ConfigurationProperties(prefix = "mysql.datasource.test1")
public class
 
 DBConfig1 {

    private String url;
    private String username;
    private String password;
    private int minPoolSize;
    private int maxPoolSize;
    private int maxLifetime;
    private int borrowConnectionTimeout;
    private int loginTimeout;
    private int maintenanceInterval;
    private int maxIdleTime;
    private String testQuery;
}

package com.toov5.configure;

import org.springframework.boot.context.properties.ConfigurationProperties;

import lombok.Data;
//讀取解析配置檔案，獲取值
@Data
@ConfigurationProperties(prefix = "mysql.datasource.test2")
public class DBConfig2 {

    private String url;
    private String username;
    private String password;
    private int minPoolSize;
    private int maxPoolSize;
    private int maxLifetime;
    private int borrowConnectionTimeout;
    private int loginTimeout;
    private int maintenanceInterval;
    private int maxIdleTime;
    private String testQuery;
}

datasource包下面：

package com.toov5.datasource;

import java.sql.SQLException;

import javax.sql.DataSource;

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.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration; 

import com.atomikos.jdbc.AtomikosDataSourceBean;
import com.mysql.jdbc.jdbc2.optional.MysqlXADataSource;
import com.toov5.configure.DBConfig1;

@Configuration
// basePackages 最好分開配置 如果放在同一個資料夾可能會報錯
//跟之前都一樣。掃包然後指定工廠
//沒有配置事務管理器，相當於將本地事務註冊到Atomikos全域性事務
@MapperScan(basePackages = "com.toov5.test01", sqlSessionTemplateRef = "testSqlSessionTemplate")
public class MyBatisConfig1 {

    // 配置資料來源
    
    @Bean(name = "testDataSource")
    public DataSource testDataSource(DBConfig1 testConfig) throws SQLException {
        MysqlXADataSource mysqlXaDataSource = new MysqlXADataSource();
        mysqlXaDataSource.setUrl(testConfig.getUrl());
        mysqlXaDataSource.setPinGlobalTxToPhysicalConnection(true);
        mysqlXaDataSource.setPassword(testConfig.getPassword());
        mysqlXaDataSource.setUser(testConfig.getUsername());
        mysqlXaDataSource.setPinGlobalTxToPhysicalConnection(true);
 
        
        //建立Atomikos全域性事務，所有的事務註冊進來
        AtomikosDataSourceBean xaDataSource = new AtomikosDataSourceBean();
        xaDataSource.setXaDataSource(mysqlXaDataSource);
        xaDataSource.setUniqueResourceName("testDataSource"); //testDataSource這個資料來源的註冊

        xaDataSource.setMinPoolSize(testConfig.getMinPoolSize());
        xaDataSource.setMaxPoolSize(testConfig.getMaxPoolSize());
        xaDataSource.setMaxLifetime(testConfig.getMaxLifetime());
        xaDataSource.setBorrowConnectionTimeout(testConfig.getBorrowConnectionTimeout());
        xaDataSource.setLoginTimeout(testConfig.getLoginTimeout());
        xaDataSource.setMaintenanceInterval(testConfig.getMaintenanceInterval());
        xaDataSource.setMaxIdleTime(testConfig.getMaxIdleTime());
        xaDataSource.setTestQuery(testConfig.getTestQuery());
        return xaDataSource;
    }

    
    @Bean(name = "testSqlSessionFactory")
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("testDataSource") DataSource dataSource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    
    @Bean(name = "testSqlSessionTemplate")
    public SqlSessionTemplate testSqlSessionTemplate(
            @Qualifier("testSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

package com.toov5.datasource;

import java.sql.SQLException;

import javax.sql.DataSource;

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.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.atomikos.jdbc.AtomikosDataSourceBean;
import com.mysql.jdbc.jdbc2.optional.MysqlXADataSource;
import com.toov5.configure.DBConfig2;

@Configuration
@MapperScan(basePackages = "com.toov5.test02", sqlSessionTemplateRef = "test2SqlSessionTemplate")
public class MyBatisConfig2 {

    // 配置資料來源
    @Bean(name = "test2DataSource")
    public DataSource testDataSource(DBConfig2 testConfig) throws SQLException {
        MysqlXADataSource mysqlXaDataSource = new MysqlXADataSource();
        mysqlXaDataSource.setUrl(testConfig.getUrl());
        mysqlXaDataSource.setPinGlobalTxToPhysicalConnection(true);
        mysqlXaDataSource.setPassword(testConfig.getPassword());
        mysqlXaDataSource.setUser(testConfig.getUsername());
        mysqlXaDataSource.setPinGlobalTxToPhysicalConnection(true);

        AtomikosDataSourceBean xaDataSource = new AtomikosDataSourceBean();
        xaDataSource.setXaDataSource(mysqlXaDataSource);
        xaDataSource.setUniqueResourceName("test2DataSource");

        xaDataSource.setMinPoolSize(testConfig.getMinPoolSize());
        xaDataSource.setMaxPoolSize(testConfig.getMaxPoolSize());
        xaDataSource.setMaxLifetime(testConfig.getMaxLifetime());
        xaDataSource.setBorrowConnectionTimeout(testConfig.getBorrowConnectionTimeout());
        xaDataSource.setLoginTimeout(testConfig.getLoginTimeout());
        xaDataSource.setMaintenanceInterval(testConfig.getMaintenanceInterval());
        xaDataSource.setMaxIdleTime(testConfig.getMaxIdleTime());
        xaDataSource.setTestQuery(testConfig.getTestQuery());
        return xaDataSource;
    }

    @Bean(name = "test2SqlSessionFactory")
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("test2DataSource") DataSource dataSource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "test2SqlSessionTemplate")
    public SqlSessionTemplate testSqlSessionTemplate(
            @Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

 service中的事務管理不需要去寫了！

package com.toov5.test02.service02;

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

import com.toov5.test01.mappertest01.UserMapperTest01;
import com.toov5.test02.mappertest02.UserMapperTest02;

import lombok.extern.slf4j.Slf4j;

@Service
@Slf4j
public class UserService02 {
  @Autowired
  private UserMapperTest01 userMapperTest01;
  @Autowired
  private UserMapperTest02 userMapperTest02;
 
  
  @Transactionalpublic int test01Andtest02(String name, Integer age){
        //連線兩個資料來源
          int result1 = userMapperTest01.insert(name, age);
          int result2 = userMapperTest02.insert(name, age);
          int i = 1/0;
          int result = result1+result2;
          return result;
      }
  
}

目錄結構：

專案啟動類

package com.toov5.app;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;

import com.toov5.configure.DBConfig1;
import com.toov5.configure.DBConfig2; @SpringBootApplication(scanBasePackages={"com.toov5.*"}) @EnableConfigurationProperties(value = { DBConfig1.class, DBConfig2.class }) //開啟讀取配置檔案，啟動時候去讀取配置檔案 public class app { public static void main(String[] args) { SpringApplication.run(app.class, args); } }

 ok,到此為止。是不是很簡單呀~