java 分布式事务seata的使用

首先创建一个seata的springboot模块并引入seata的起步依赖

    com.alibaba.cloud
    spring-cloud-starter-alibaba-seata

模块的目录结构如下

seata.yaml中的内容为：

seata:
  tx-service-group: seata-toutiao
  service:
    vgroup-mapping: # 事务组与cluster的映射关系
      seata-toutiao: DEFAULT
    grouplist:
      DEFAULT: 192.168.211.136:8091

spring.factories中的内容为：

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.jjw.core.seata.SeataHeimaAutoConfiguration
org.springframework.boot.env.EnvironmentPostProcessor=\
com.jjw.core.seata.MyEnvironmentPostProcessor

MyEnvironmentPostProcessor中的内容为：

package com.jjw.core.seata;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.boot.env.YamlPropertySourceLoader;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

import java.io.IOException;
import java.util.List;

/**
 * 自定义环境处理，在运行SpringApplication之前加载任意配置文件到Environment环境中
 */

public class MyEnvironmentPostProcessor implements EnvironmentPostProcessor {

    //Properties对象
    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        //自定义配置文件
        String[] profiles = {
                "seata.yaml"
        };
        //循环添加
        for (String profile : profiles) {
            //从classpath路径下面查找文件
            Resource resource = new ClassPathResource(profile);
            //加载成PropertySource对象，并添加到Environment环境中
            environment.getPropertySources().addFirst(loadProfiles(resource));
        }
    }

    //加载单个配置文件
    private PropertySource loadProfiles(Resource resource) {
        if (!resource.exists()) {
            throw new IllegalArgumentException("资源" + resource + "不存在");
        }
        try {
            YamlPropertySourceLoader yamlPropertySourceLoader = new YamlPropertySourceLoader();
            List> resources = yamlPropertySourceLoader.load(resource.getFilename(), resource);
            return resources.get(0);
        } catch (IOException ex) {
            throw new IllegalStateException("加载配置文件失败" + resource, ex);
        }
    }
}

SeataHeimaAutoConfiguration中的内容为：

package com.jjw.core.seata;

import io.seata.rm.datasource.DataSourceProxy;
import io.seata.spring.boot.autoconfigure.properties.SeataProperties;
import io.seata.spring.boot.autoconfigure.properties.client.ServiceProperties;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.HashMap;
import java.util.Map;


/**
 * --加载文件properties
 * https://www.cnblogs.com/huanzi-qch/p/11122107.html
 * --加载yaml
 * https://blog.csdn.net/baidu_28523317/article/details/108701391
 *
 * --顺序
 * https://blog.csdn.net/f641385712/article/details/105596178
 *
 * --可能存在的问题
 * https://segmentfault.com/q/1010000040364236
 */
@Configuration
@ConditionalOnClass(DataSourceProxy.class)
public class SeataHeimaAutoConfiguration {

    //仅仅用作测试
    @Bean
    public Map seatax(SeataProperties seataProperties,
                                     ServiceProperties serviceProperties){
        String txServiceGroup = seataProperties.getTxServiceGroup();
        System.out.println(txServiceGroup);
        System.out.println(serviceProperties.getGrouplist());
        return new HashMap<>();
    }
}

在需要用到分布式事务的微服务中添加依赖(用到几个微服务就给相应的微服务都添加分布式事务依赖)、且对这几个微服务所在的库都添加一个undolog表：

-- auto-generated definition
create table undo_log
(
    id            bigint auto_increment
        primary key,
    branch_id     bigint       not null,
    xid           varchar(100) not null,
    context       varchar(128) not null,
    rollback_info longblob     not null,
    log_status    int          not null,
    log_created   datetime     not null,
    log_modified  datetime     not null,
    ext           varchar(100) null,
    constraint ux_undo_log
        unique (xid, branch_id)
)
    charset = utf8;

在最开始使用分布式事务的那个微服务上的方法上添加事务注解

@GlobalTransactional // 全局事务
@Transactional // 本地事务
@Override
public void pass(Integer id) {