TransactionManager.java

package cn.dreampie.orm;

import cn.dreampie.log.Logger;
import cn.dreampie.orm.exception.TransactionException;

import java.sql.Connection;
import java.sql.SQLException;

/**
 * Created by wangrenhui on 15/4/3.
 */
public class TransactionManager {
  private final static Logger logger = Logger.getLogger(TransactionManager.class);
  private DataSourceMeta dataSourceMeta;
  private boolean begined;
  private int level;//事务级别
  private Boolean readonly;//只读
  private Boolean autoCommit;

  public TransactionManager(DataSourceMeta dataSourceMeta, boolean readonly, int level) {
    this.dataSourceMeta = dataSourceMeta;
    this.readonly = readonly;
    this.level = level;
  }

  /**
   * 是不是已经开始了
   *
   * @return boolean
   */
  public boolean isBegined() {
    return begined;
  }

  /**
   * 开始事务
   */
  public void begin() throws TransactionException {
    Connection conn = dataSourceMeta.getCurrentConnection();
    try {
      if (readonly == null || !readonly) {
        if (conn == null) {
          conn = dataSourceMeta.getWriteConnection();
          dataSourceMeta.setCurrentConnection(conn);
        }
        autoCommit = conn.getAutoCommit();
        if (conn.getAutoCommit()) {
          conn.setAutoCommit(false);
        }

        logger.info("Connection for " + dataSourceMeta.getWriteDsName() + " has opened success.");
      } else {

        if (conn == null) {
          conn = dataSourceMeta.getReadConnection();
          dataSourceMeta.setCurrentConnection(conn);
        }
        readonly = conn.isReadOnly();
        conn.setReadOnly(true);

        logger.info("Connection for " + dataSourceMeta.getReadDsName() + " has opened success.");
      }
      conn.setTransactionIsolation(level);
    } catch (SQLException e) {
      throw new TransactionException(e.getMessage(), e);
    } finally {
      begined = true;
    }
  }

  /**
   * 提交事务
   */
  public void commit() throws TransactionException {
    Connection conn = dataSourceMeta.getCurrentConnection();
    try {
      if (conn != null) {
        if (readonly == null || !readonly) {
          if (!conn.getAutoCommit()) {
            conn.commit();
            logger.info("Connection for " + dataSourceMeta.getWriteDsName() + " has commited success.");
          }
        }
      }
    } catch (SQLException e) {
      throw new TransactionException(e.getMessage(), e);
    }
  }

  /**
   * 设置Connection的原始状态
   */
  public void end() {
    Connection conn = dataSourceMeta.getCurrentConnection();
    try {
      if (conn != null) {
        if (autoCommit != null) {
          conn.setAutoCommit(autoCommit);
          autoCommit = null;
        }
        if (readonly != null) {
          conn.setReadOnly(readonly);
          readonly = null;
        }
        dataSourceMeta.rmCurrentConnection();
        dataSourceMeta.close(conn);

        if (readonly == null || !readonly) {
          logger.info("Connection for " + dataSourceMeta.getWriteDsName() + " has closed success.");
        } else {
          logger.info("Connection for " + dataSourceMeta.getReadDsName() + " has closed success.");
        }
      }
    } catch (SQLException e) {
      if (readonly == null || !readonly) {
        logger.error("Could not end connection for " + dataSourceMeta.getWriteDsName() + ".", e);
      } else {
        logger.error("Could not end connection for " + dataSourceMeta.getReadDsName() + ".", e);
      }

    }
  }

  /**
   * 发生异常回滚事务
   */
  public void rollback() {
    Connection conn = dataSourceMeta.getCurrentConnection();
    try {
      if (conn != null) {
        if (readonly == null || !readonly) {
          conn.rollback();
          logger.info("Connection for " + dataSourceMeta.getWriteDsName() + " has rollbacked success.");
        }
      }
    } catch (SQLException e) {
      logger.error("Could not rollback connection for " + dataSourceMeta.getWriteDsName() + ".", e);
    }
  }
}