java通过反射拿到mybatis中的sql语句并操作

private static final int MaxBatchLength = 100;

public void updateBatch(List<T>list, BaseMapper<T> mapper){

         if (!Proxy.isProxyClass(mapper.getClass())){
             throw new RuntimeException("mapper必须是代理对象");
         }
        InvocationHandler invocationHandler = Proxy.getInvocationHandler(mapper);
         if (null==invocationHandler){
             throw new RuntimeException("mapper必须是有处理器的代理对象");
         }
        Field fieldSession;
        try {
            fieldSession = invocationHandler.getClass().getDeclaredField("sqlSession");
        } catch (NoSuchFieldException e) {
            throw new RuntimeException("从mapper代理对象中获取不到sqlSession", e);
        }
        Field fieldMapper;
        try {
            fieldMapper = invocationHandler.getClass().getDeclaredField("mapperInterface");
        } catch (NoSuchFieldException | SecurityException e) {
            throw new RuntimeException("从mapper代理对象中获取不到mapperInterface", e);
        }
        fieldSession.setAccessible(true);
        SqlSession session;
        try {
            session = (SqlSession) fieldSession.get(invocationHandler);
        } catch (IllegalArgumentException | IllegalAccessException e) {
            throw new RuntimeException("从mapper代理对象中获取sqlSession失败，不应该出现此异常", e);
        }
        fieldMapper.setAccessible(true);
        Class<?> mapperInterface;
        try {
            mapperInterface = (Class<?>) fieldMapper.get(invocationHandler);
        } catch (IllegalArgumentException | IllegalAccessException e) {
            throw new RuntimeException("从mapper代理对象中获取mapperInterface失败，不应该出现此异常", e);
        }
        // 方法名(mybatis的对应xml中的sql语句的id)
        String methodName = mapperInterface.getName() + ".updateEntityBatch";
        System.out.println("获取方法的SQL："+methodName);
        //传递参数保证，要更新的字段存在（若没有判空，则可以不用传递参数）
        BoundSql boundSql = session.getConfiguration().getMappedStatement(methodName).getBoundSql(list.get(0));

        //是否是独立的事务
        boolean atmo = true, succ = false;
        System.out.println("每次批量执行最大长度为："+MaxBatchLength );

        //获取批量执行的sql
        String sql = boundSql.getSql();
        //获取连接
        Connection connection = null;
        PreparedStatement ps = null;
        List<Closeable> closeables = new LinkedList<>();
        try {
            connection = session.getConnection();
            if (atmo = null == connection || connection.isClosed()) {
                DataSource dataSource = session.getConfiguration().getEnvironment().getDataSource();
                connection = dataSource.getConnection();
                //事务不自动提交
                connection.setAutoCommit(false);
                System.out.println("session中的连接不可使用，使用独立的连接和事务");
            } else {
                System.out.println("使用session的连接，事务和session保持一致");
            }

            ps = connection.prepareStatement(sql);

            int index = 0;
            System.out.println("需要批量更新"+list.size()+"个对象");

            for (int i = 0, j = list.size(); i < j; i++, index++) {
                T t = list.get(i);
                //将实体类转换为map
                BeanMap map = BeanMap.create(t);
                System.out.println("绑定对象:"+ map);
                for (int ii = 1, jj = boundSql.getParameterMappings().size(); ii <= jj; ii++) {
                    ParameterMapping parameterMapping = boundSql.getParameterMappings().get(ii - 1);
                    String name = parameterMapping.getProperty();
                    Object value = map.get(name);
                    if (null == value) {
                        // 为空时候尝试取默认值
                        value = map.get(name + "Default");
                    }
                    if (null != value && value instanceof Date) {
                        Timestamp date = new Timestamp(((Date) value).getTime());
                        value = date;
                    }
                    // 单独处理clob类型
                    if (JdbcType.CLOB.equals(parameterMapping.getJdbcType())) {
                        StringReader sr = new StringReader(null == value ? "" : value.toString());
                        ps.setClob(ii, sr);
                        closeables.add(sr);
                    } else {
                        ps.setObject(ii, value, parameterMapping.getJdbcType().TYPE_CODE);
                    }
                }
                ps.addBatch();
                if (index > MaxBatchLength) {
                     ps.executeBatch();
                    ps.clearBatch();
                    index = 0;
                }
            }
            if (index > 0) {
                //执行剩下的
                ps.executeBatch();
            }
            succ = true;
        }catch (Exception e){
            throw new RuntimeException("批量更新失败",e);
        }finally {
            // 如果是独立的事务
            if (atmo && null != connection) {
               log.info("检测到独立事务，判断提交/回滚");
                if (succ) {
                    try {
                        connection.commit();
                        log.info("独立事务提交成功");
                    } catch (SQLException e) {
                        log.info("独立事务提交失败");
                        throw new RuntimeException(e);
                    }
                } else {
                    try {
                        connection.rollback();
                        log.info("独立事务回滚成功");
                    } catch (SQLException e) {
                        log.info("独立事务回滚失败");
                        throw new RuntimeException(e);
                    }
                }
            }
            if (null != ps) {
                try {
                    ps.close();
                } catch (SQLException e) {
                   e.printStackTrace();
                }
            }
            if (atmo && null != connection) {
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            for (Closeable closeable : closeables) {
                try {
                    closeable.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }