Java事物(MySql)

1.自己总结的,很简单的Java事物 ---个人笔记记录.

/** * 学生批量转班 * @param inv * @return * @throws Exception */@Get("studentClassTransfer")public String studentClassTransfer(Invocation inv, @Param("check_list") List<Integer> check_list, @Param("pid") int pid, @Param("gid") int gid,@Param("cid") int cid) throws Exception {Date d = new Date();// 查询当前学生是那个阶段,年级,班级的,如何和要转的一样就不转了if (check_list.size() > 0) {for (int i = 0; i < check_list.size(); i++) {StudentClassInfo stuClass = classInfoDAO.getCidToUid(check_list.get(i));if (stuClass != null) {// 根据班级级id查出年级idClassInfo classInfo = classInfoDAO.getGidToCid(stuClass.getCid());if (classInfo != null) {// 根据年级id查出学段idGradeInfo gradeInfo = gradeInfoDAO.getGrade(classInfo.getGid());if (gradeInfo != null) {if (gradeInfo.getPid() == pid && classInfo.getGid() == gid && stuClass.getCid() == cid) {// 要转的和本用户一样就不转了}else {// 加入事物// 1.先删除当前用户原在班级(uid)classInfoDAO.delStudentClass();// 2.在新班级里添加一条记录classInfoDAO.insertStudentClass()StudentManageController s = new StudentManageController();String sqlDel = "update t_student_class set flag = 1 where uid = " + check_list.get(i) + "";String sqlIns = "insert into t_student_class(uid,cid,inserttime) values(" + check_list.get(i) + "," + cid + "," + d.getTime()+ ")";String sqlAll[] = { sqlDel, sqlIns };StartTransaction(s.getConnection(), sqlAll);}}}}}}return "@<script>location.href='lookStudentInfo'</script>";}/** * 链接数据库 获取Connection * @return */public Connection getConnection() {String driver = "com.mysql.jdbc.Driver";String url = "jdbc:mysql://*************/fyzxx?useUnicode=true&characterEncoding=utf8";String user = "****";String password = "******";Connection conn = null;try {Class.forName(driver);}catch (ClassNotFoundException e) {e.printStackTrace();}try {conn = DriverManager.getConnection(url, user, password);if (!conn.isClosed())System.out.println("Succeeded connecting to the Database!");}catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return conn;}/** * 事物处理 * @param con * @param sqls * @throws Exception */public void StartTransaction(Connection con, String[] sqls) throws Exception {if (sqls == null) {return;}Statement sm = null;try {// 事务开始System.out.println("事务处理开始！");con.setAutoCommit(false); // 设置连接不自动提交，即用该连接进行的操作都不更新到数据库sm = con.createStatement(); // 创建Statement对象// 依次执行传入的SQL语句for (int i = 0; i < sqls.length; i++) {sm.execute(sqls[i]);// 执行添加事物的语句}System.out.println("提交事务处理！");con.commit(); // 提交给数据库处理System.out.println("事务处理结束！");// 事务结束// 捕获执行SQL语句组中的异常}catch (SQLException e) {try {System.out.println("事务执行失败，进行回滚！\n");con.rollback(); // 若前面某条语句出现异常时，进行回滚，取消前面执行的所有操作}catch (SQLException e1) {e1.printStackTrace();}}finally {sm.close();}}