摘录JDBC实现XA事务原理代码

import com.mysql.jdbc.jdbc2.optional.MysqlXAConnection;
import com.mysql.jdbc.jdbc2.optional.MysqlXid;
import javax.sql.XAConnection;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class MysqlXAConnectionTest {
   public static void main(String[] args) throws SQLException {
      //true表示打印XA语句,，用于调试
      boolean logXaCommands = true;
      // 获得资源管理器操作接口实例 RM1
      Connection conn1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "shxx12151022");
      XAConnection xaConn1 = new MysqlXAConnection((com.mysql.jdbc.Connection) conn1, logXaCommands);
      XAResource rm1 = xaConn1.getXAResource();
      // 获得资源管理器操作接口实例 RM2
      Connection conn2 = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root",
            "shxx12151022");
      XAConnection xaConn2 = new MysqlXAConnection((com.mysql.jdbc.Connection) conn2, logXaCommands);
      XAResource rm2 = xaConn2.getXAResource();
      // AP请求TM执行一个分布式事务，TM生成全局事务id
      byte[] gtrid = "g12345".getBytes();
      int formatId = 1;
      try {
         // ==============分别执行RM1和RM2上的事务分支====================
         // TM生成rm1上的事务分支id
         byte[] bqual1 = "b00001".getBytes();
         Xid xid1 = new MysqlXid(gtrid, bqual1, formatId);
         // 执行rm1上的事务分支
         rm1.start(xid1, XAResource.TMNOFLAGS);//One of TMNOFLAGS, TMJOIN, or TMRESUME.
         PreparedStatement ps1 = conn1.prepareStatement("INSERT into user(name) VALUES ('tianshouzhi')");
         ps1.execute();
         rm1.end(xid1, XAResource.TMSUCCESS);
         // TM生成rm2上的事务分支id
         byte[] bqual2 = "b00002".getBytes();
         Xid xid2 = new MysqlXid(gtrid, bqual2, formatId);
         // 执行rm2上的事务分支
         rm2.start(xid2, XAResource.TMNOFLAGS);
         PreparedStatement ps2 = conn2.prepareStatement("INSERT into user(name) VALUES ('wangxiaoxiao')");
         ps2.execute();
         rm2.end(xid2, XAResource.TMSUCCESS);
         // ===================两阶段提交================================
         // phase1：询问所有的RM 准备提交事务分支
         int rm1_prepare = rm1.prepare(xid1);
         int rm2_prepare = rm2.prepare(xid2);
         // phase2：提交所有事务分支
         boolean onePhase = false; //TM判断有2个事务分支，所以不能优化为一阶段提交
         if (rm1_prepare == XAResource.XA_OK
               && rm2_prepare == XAResource.XA_OK
               ) {//所有事务分支都prepare成功，提交所有事务分支
            rm1.commit(xid1, onePhase);
            rm2.commit(xid2, onePhase);
         } else {//如果有事务分支没有成功，则回滚
            rm1.rollback(xid1);
            rm1.rollback(xid2);
         }
      } catch (XAException e) {
         // 如果出现异常，也要进行回滚
         e.printStackTrace();
      }
   }
}