[SPARK-12164] [SQL] Decode the encoded values and then display

sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala

@@ -165,13 +165,11 @@ class DataFrame private[sql](
    * @param _numRows Number of rows to show
    * @param truncate Whether truncate long strings and align cells right
    */
-  private[sql] def showString(_numRows: Int, truncate: Boolean = true): String = {
+  override private[sql] def showString(_numRows: Int, truncate: Boolean = true): String = {
     val numRows = _numRows.max(0)
-    val sb = new StringBuilder
     val takeResult = take(numRows + 1)
     val hasMoreData = takeResult.length > numRows
     val data = takeResult.take(numRows)
-    val numCols = schema.fieldNames.length
 
     // For array values, replace Seq and Array with square brackets
     // For cells that are beyond 20 characters, replace it with the first 17 and "..."
@@ -187,50 +185,7 @@ class DataFrame private[sql](
       }: Seq[String]
     }
 
-    // Initialise the width of each column to a minimum value of '3'
-    val colWidths = Array.fill(numCols)(3)
-
-    // Compute the width of each column
-    for (row <- rows) {
-      for ((cell, i) <- row.zipWithIndex) {
-        colWidths(i) = math.max(colWidths(i), cell.length)
-      }
-    }
-
-    // Create SeparateLine
-    val sep: String = colWidths.map("-" * _).addString(sb, "+", "+", "+\n").toString()
-
-    // column names
-    rows.head.zipWithIndex.map { case (cell, i) =>
-      if (truncate) {
-        StringUtils.leftPad(cell, colWidths(i))
-      } else {
-        StringUtils.rightPad(cell, colWidths(i))
-      }
-    }.addString(sb, "|", "|", "|\n")
-
-    sb.append(sep)
-
-    // data
-    rows.tail.map {
-      _.zipWithIndex.map { case (cell, i) =>
-        if (truncate) {
-          StringUtils.leftPad(cell.toString, colWidths(i))
-        } else {
-          StringUtils.rightPad(cell.toString, colWidths(i))
-        }
-      }.addString(sb, "|", "|", "|\n")
-    }
-
-    sb.append(sep)
-
-    // For Data that has more than "numRows" records
-    if (hasMoreData) {
-      val rowsString = if (numRows == 1) "row" else "rows"
-      sb.append(s"only showing top $numRows $rowsString\n")
-    }
-
-    sb.toString()
+    formatString ( rows, numRows, hasMoreData, truncate )
   }
 
   /**

sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala

@@ -225,7 +225,41 @@ class Dataset[T] private[sql](
    *
    * @since 1.6.0
    */
-  def show(numRows: Int, truncate: Boolean): Unit = toDF().show(numRows, truncate)
+  // scalastyle:off println
+  def show(numRows: Int, truncate: Boolean): Unit = println(showString(numRows, truncate))
+  // scalastyle:on println
+
+  /**
+    * Compose the string representing rows for output
+    * @param _numRows Number of rows to show
+    * @param truncate Whether truncate long strings and align cells right
+    */
+  override private[sql] def showString(_numRows: Int, truncate: Boolean = true): String = {
+    val numRows = _numRows.max(0)
+    val takeResult = take(numRows + 1)
+    val hasMoreData = takeResult.length > numRows
+    val data = takeResult.take(numRows)
+
+    // For array values, replace Seq and Array with square brackets
+    // For cells that are beyond 20 characters, replace it with the first 17 and "..."
+    val rows: Seq[Seq[String]] = schema.fieldNames.toSeq +: (data.map {
+      case r: Row => r
+      case tuple: Product => Row.fromTuple(tuple)
+      case o => Row(o)
+    } map { row =>
+      row.toSeq.map { cell =>
+        val str = cell match {
+          case null => "null"
+          case array: Array[_] => array.mkString("[", ", ", "]")
+          case seq: Seq[_] => seq.mkString("[", ", ", "]")
+          case _ => cell.toString
+        }
+        if (truncate && str.length > 20) str.substring(0, 17) + "..." else str
+      }: Seq[String]
+    })
+
+    formatString ( rows, numRows, hasMoreData, truncate )
+  }
 
   /**
     * Returns a new [[Dataset]] that has exactly `numPartitions` partitions.

sql/core/src/main/scala/org/apache/spark/sql/execution/Queryable.scala

@@ -19,6 +19,7 @@ package org.apache.spark.sql.execution
 
 import scala.util.control.NonFatal
 
+import org.apache.commons.lang3.StringUtils
 import org.apache.spark.sql.SQLContext
 import org.apache.spark.sql.types.StructType
 
@@ -42,4 +43,67 @@ private[sql] trait Queryable {
   def explain(extended: Boolean): Unit
 
   def explain(): Unit
+
+  private[sql] def showString(_numRows: Int, truncate: Boolean = true): String
+
+  /**
+    * Format the string representing rows for output
+    * @param rows The rows to show
+    * @param numRows Number of rows to show
+    * @param hasMoreData Whether some rows are not shown due to the limit
+    * @param truncate Whether truncate long strings and align cells right
+    *
+    */
+  private[sql] def formatString (rows: Seq[Seq[String]],
+                                 numRows: Int,
+                                 hasMoreData : Boolean,
+                                 truncate: Boolean = true): String = {
+    val sb = new StringBuilder
+    val numCols = schema.fieldNames.length
+
+    // Initialise the width of each column to a minimum value of '3'
+    val colWidths = Array.fill(numCols)(3)
+
+    // Compute the width of each column
+    for (row <- rows) {
+      for ((cell, i) <- row.zipWithIndex) {
+        colWidths(i) = math.max(colWidths(i), cell.length)
+      }
+    }
+
+    // Create SeparateLine
+    val sep: String = colWidths.map("-" * _).addString(sb, "+", "+", "+\n").toString()
+
+    // column names
+    rows.head.zipWithIndex.map { case (cell, i) =>
+      if (truncate) {
+        StringUtils.leftPad(cell, colWidths(i))
+      } else {
+        StringUtils.rightPad(cell, colWidths(i))
+      }
+    }.addString(sb, "|", "|", "|\n")
+
+    sb.append(sep)
+
+    // data
+    rows.tail.map {
+      _.zipWithIndex.map { case (cell, i) =>
+        if (truncate) {
+          StringUtils.leftPad(cell.toString, colWidths(i))
+        } else {
+          StringUtils.rightPad(cell.toString, colWidths(i))
+        }
+      }.addString(sb, "|", "|", "|\n")
+    }
+
+    sb.append(sep)
+
+    // For Data that has more than "numRows" records
+    if (hasMoreData) {
+      val rowsString = if (numRows == 1) "row" else "rows"
+      sb.append(s"only showing top $numRows $rowsString\n")
+    }
+
+    sb.toString()
+  }
 }