package easyJ.database.session;
import java.sql.*;
import easyJ.common.EasyJException;
public class TransactionJDBCImpl extends Transaction {
private Connection conn;
// 提交次数
private int commitCount;
// 事务嵌套层次
private int transDeep;
public TransactionJDBCImpl() {}
public TransactionJDBCImpl(Connection conn) throws EasyJException{
try {
this.conn = conn;
conn.setAutoCommit(false);
commitCount = 0;
transDeep = 0;
} catch (SQLException ex) {
String clientMessage = "服务器忙";
String location = "easyJ.database.transaction.TransactionJDBCImpl.begin()";
String logMessage = "数据库事务启动失败！信息：" + ex.getMessage();
EasyJException ee = new EasyJException(ex, location, logMessage,
clientMessage);
throw ee;
}
}
protected void begin() {
transDeep++;
}
public Connection getConnection() {
return conn;
}
public void commit() throws EasyJException {
try {
if (transDeep > 1) {
transDeep--;
commitCount++;
return;
} else if (transDeep == 1) {
conn.commit();
conn.setAutoCommit(true);
conn.close();
conn = null;
} else {
String clientMessage = "服务器忙";
String location = "easyJ.database.transaction.TransactionJDBCImpl.commit()";
String logMessage = "数据库事务提交失败！信息：" + "不能没有启动事务就提交";
throw new EasyJException(null, location, logMessage,
clientMessage);
}
} catch (SQLException ex) {
String clientMessage = "服务器忙";
String location = "easyJ.database.transaction.TransactionJDBCImpl.commit()";
String logMessage = "数据库事务提交失败！信息：" + ex.getMessage();
EasyJException ee = new EasyJException(ex, location, logMessage,
clientMessage);
throw ee;
}
}
/**
* 结束一个事务，如果事务本身不是第一层，则只是简单的把当前的层次减1，
* 只有当到达第一层之后才真正的执行rollback。
*/
public void rollback() throws EasyJException {
if (transDeep > 1) {
transDeep--;
return;
}
// 如果不是所有的事务都正常提交了，则需要回滚
try {
if (transDeep == 1) {
conn.rollback();
}
} catch (SQLException ex) {
String clientMessage = "服务器忙";
String location = "easyJ.database.transaction.TransactionJDBCImpl.end()";
String logMessage = "数据库事务回滚失败！信息：" + ex.getMessage();
EasyJException ee = new EasyJException(ex, location, logMessage,
clientMessage);
throw ee;
} finally {
try {
conn.close();
conn = null;
} catch (SQLException se) {}
}
}
}