cglib根據數據動態生成對象

最近有個任務：根據查詢SQL直接導出報表

實現關鍵是，怎么根據sql查詢的數據動態生成對象列表，想到Cglib動態代理實現

廢話少說，上代碼：

定義動態生成Java Bean類：

import java.util

import net.sf.cglib.beans.{BeanGenerator, BeanMap}

/**
  * 動態Bean生成
  *
  * @author BarryWang create at 2018/6/19 11:54
  * @version 0.0.1
  */
class DynamicBean {
  private var `object`: AnyRef = null
  private var beanMap: BeanMap = null

  def this(fieldTypeMap: util.Map[String, AnyRef]) {
    this()
    this.`object` = generateObject(fieldTypeMap)
    this.beanMap = BeanMap.create(this.`object`)
  }

  /**
    * 生成對象
    *
    * @param fieldTypeMap 域及類型Map
    * @return
    */
  private def generateObject(fieldTypeMap: util.Map[String, AnyRef]) = {
    val generator = new BeanGenerator
    val keySet = fieldTypeMap.keySet
    val i = keySet.iterator
    while (i.hasNext) {
      val key = i.next
      generator.addProperty(key, fieldTypeMap.get(key).asInstanceOf[Class[_]])
    }
    generator.create
  }

  /**
    * 設置域值
    *
    * @param filedName 域名
    * @param value     值
    */
  def setValue(filedName: String, value: AnyRef): Unit = {
    this.beanMap.put(filedName, value)
  }

  /**
    * 獲取域值
    *
    * @param fieldName 域名
    * @return
    */
  def getValue(fieldName: String): AnyRef = this.beanMap.get(fieldName)

  /**
    * 最終對象
    *
    * @return
    */
  def getObject: AnyRef = this.`object`
}

SQL查詢數據轉對象：

  /**
    * 根據數據查出數據轉成對象列表
    * @param database 數據庫
    * @param querySql 查詢SQl
    * @return
    */
  def getObjectDataList(database: String, querySql: String): ArrayList[Object] = {
    println(s"database:${database} sql:${querySql}")
    val rs = DataGenerator.getResultSet(database, querySql)
    val md = rs.getMetaData
    val colCount = md.getColumnCount
    val fieldValMap = new JavaHashMap[String, AnyRef]()
    for (i <- 0 to colCount - 1) {
      fieldValMap.put(underLineToCamel(md.getColumnName(i + 1)), Class.forName("java.lang.String"))
    }
    // 生成動態 Bean
    val returnList = new ArrayList[Object]();
    while (rs.next()) {
      val objectBean = new DynamicBean(fieldValMap);
      for (i <- 0 to colCount - 1) {
        val data = getData(md, i+1, rs)
        objectBean.setValue(underLineToCamel(md.getColumnName(i + 1)), data)
      }
//      println(">> " + objectBean.getValue("zhCnName"))
      returnList.add(objectBean.getObject)
    }
    rs.close()
    returnList
  }

  def underLineToCamel(name: String): String = {
    val result = new StringBuilder
    // 快速檢查
    if (name == null || name.isEmpty) { // 沒必要轉換
      return ""
      //        } else if (!name.contains("_")) {
      //            // 不含下划線，僅將首字母小寫
      //            return name.substring(0, 1).toLowerCase() + name.substring(1);
    }
    // 用下划線將原始字符串分割
    val camels = name.split("_")
    for (camel <- camels) { // 跳過原始字符串中開頭、結尾的下換線或雙重下划線
      // 處理真正的駝峰片段
      if (result.length == 0) { // 第一個駝峰片段，全部字母都小寫
        result.append(camel.toLowerCase)
      }
      else { // 其他的駝峰片段，首字母大寫
        result.append(camel.substring(0, 1).toUpperCase)
        result.append(camel.substring(1).toLowerCase)
      }
    }
    result.toString
  }

/**
  * 從ResultSet取數
  * @param md
  * @param index
  * @param rs
  * @return
  */
def getData(md: ResultSetMetaData, index: Int, rs: ResultSet): String = {
  md.getColumnType(index)  match {
    case Types.DECIMAL => {
      val value = rs.getBigDecimal(index)
      val bigDecimal = value == null match {
        case true => "0.0000"
        case false => value.setScale(4, RoundingMode.HALF_UP).toString()
      }
      return bigDecimal
    }
    case Types.TIMESTAMP =>{
      val value = rs.getTimestamp(index)
      val timestamp = value == null match {
        case true => ""
        case false => DateTools.format(new Date(rs.getTimestamp(index).getTime))
      }
      return timestamp
    }
    case Types.DATE => {
      val value = rs.getDate(index)
      val date = value == null match {
        case true => ""
        case false => DateTools.format(rs.getDate(index), DateTools.DATE_PATTERN)
      }
      return date
    }
    case _ => {
      val value = rs.getObject(index)
      val data = value == null match {
        case true => ""
        case false => rs.getObject(index).toString
      }
      return data
    }
  }
}