content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  package com.aliyun.odps.udf.local.datasource;
  
  import java.io.IOException;
  
  public abstract class InputSource {
  
    /**
     * 添加输入源时会调用该方法进行初始化，如：打开文件句柄，打开数据库连接等
     * 
     * @throws IOException
     */
    public void setup() throws IOException{};
  
    /**
     * 每次调用该方法返回一条记录，Object对象类型只能为：Long,Double,Boolean,Datetime,String
     * @return
     * @throws IOException
     */
    public abstract Object[] getNextRow() throws IOException;
  
    /**
     * 该方法用于释放资源，如：关闭文件句柄，关闭数据库连接
     * 程序退出之前（正常退出或抛出异常）会调用该方法，不应该抛出异常
     */
    public void close(){};
  
  }
  