spark 中创建外部表工具方法

import scala.collection.JavaConversions._
import java.util

/**
  *
  *
  *
  * def tag_categoryTableColumns() = {
  *
  * val columnsMap = new util.LinkedHashMap[String, String]()
  *     columnsMap.put("tag_id", "string")
  *     columnsMap.put("tag_group", "string")
  *     columnsMap.put("lable_lv1", "string")
  *     columnsMap.put("lable_lv2", "string")
  *     columnsMap.put("lable_lv3", "string")
  *     columnsMap.put("lable_lv4", "string")
  *     columnsMap.put("show_name", "string")
  *
  *
  * columnsMap
  * }
  *
  */


object HiveDBUtils {


  /**
    * 创建外部分区表
    * CREATE EXTERNAL TABLE IF NOT EXISTS app(tag_id string,lable_lv1 string,lable_lv2 string,lable_lv3 string,lable_lv4 string) PARTITIONED BY (year string) ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' LOCATION '/user/app'
    */

  def createExternalTableWithPartition(tableName:String,columnsMap :util.LinkedHashMap[String, String],partitionMap:java.util.LinkedHashMap[String, String],location:String,terminator:String) ={

    val colums = parseForTableColoums(columnsMap)

    val partition = parseForTableColoums(partitionMap)
    val createHqlStatement: String = "CREATE EXTERNAL TABLE IF NOT EXISTS "
      .concat(tableName)
      .concat(colums)
      .concat(" PARTITIONED BY ")
      .concat(partition)
      .concat(" ROW FORMAT DELIMITED FIELDS TERMINATED BY ")
      .concat("'")
      .concat(terminator)
      .concat("'")
      .concat(" LOCATION ")
      .concat("'")
      .concat(location)
      .concat("'")
    createHqlStatement

  }


  /**
    * 创建无分区外部表
    *
    * CREATE EXTERNAL TABLE IF NOT EXISTS app(tag_id string,tag_group string,lable_lv1 string,lable_lv2 string,lable_lv3 string,lable_lv4 string,show_name string) ROW FORMAT DELIMITED FIELDS TERMINATED BY  ','  LOCATION  '/user/app'
    */




  def createExternalTableNoPartition(tableName:String,columnsMap :util.Map[String, String],location:String,terminator:String) ={

    val columns = parseForTableColoums(columnsMap)

    val createHqlStatement: String = "CREATE EXTERNAL TABLE IF NOT EXISTS "
      .concat(tableName)
      .concat(columns)
      .concat(" ROW FORMAT DELIMITED FIELDS TERMINATED BY ")
      .concat(" '")
      .concat(terminator)
      .concat("' ")
      .concat(" LOCATION ")
      .concat(" '")
      .concat(location)
      .concat("' ")
    createHqlStatement

  }

  def parseForTableColoums(keywords: java.util.Map[String, String]) ={

    var keywordsHandled: String = ""
    for ((field, desc) <- keywords) {

      keywordsHandled += field
        .concat(" ")
        .concat(keywords.get(field))
        .concat(",")
    }

    keywordsHandled = keywordsHandled.reverse.replaceFirst(",", "").reverse

    "(".concat(keywordsHandled).concat(")")

  }

  def parseForTableColoumsName(keywords: java.util.Map[String, String]) = {

    var keywordsHandled: String = ""

    for ((field, desc) <- keywords) {
      keywordsHandled += field
        .concat(",")
    }

    keywordsHandled = keywordsHandled.reverse.replaceFirst(",", "").reverse

    " ".concat(keywordsHandled).concat(" ")

  }