[SPARK-5090] [EXAMPLES] The improvement of python converter for hbase

Hi,

Following the discussion in http://apache-spark-developers-list.1001551.n3.nabble.com/python-converter-in-HBaseConverter-scala-spark-examples-td10001.html. I made some modification in three files in package examples:
1. HBaseConverters.scala: the new converter will converts all the records in an hbase results into a single string
2. hbase_input.py: as the value string may contain several records, we can use ast package to convert the string into dict
3. HBaseTest.scala: as the package examples use hbase 0.98.7 the original constructor HTableDescriptor is deprecated. The updation to new constructor is made

Author: GenTang <gen.tang86@gmail.com>

Closes #3920 from GenTang/master and squashes the following commits:

d2153df [GenTang] import JSONObject precisely
4802481 [GenTang] dump the result into a singl String
62df7f0 [GenTang] remove the comment
21de653 [GenTang] return the string in json format
15b1fe3 [GenTang] the modification of comments
5cbbcfc [GenTang] the improvement of pythonconverter
ceb31c5 [GenTang] the modification for adapting updation of hbase
3253b61 [GenTang] the modification accompanying the improvement of pythonconverter

1 files changed, 17 insertions, 3 deletions

diff --git a/examples/src/main/scala/org/apache/spark/examples/pythonconverters/HBaseConverters.scala b/examples/src/main/scala/org/apache/spark/examples/pythonconverters/HBaseConverters.scala
index 273bee0a8b..90d48a6410 100644
--- a/examples/src/main/scala/org/apache/spark/examples/pythonconverters/HBaseConverters.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/pythonconverters/HBaseConverters.scala
@@ -18,20 +18,34 @@
 package org.apache.spark.examples.pythonconverters
 
 import scala.collection.JavaConversions._
+import scala.util.parsing.json.JSONObject
 
 import org.apache.spark.api.python.Converter
 import org.apache.hadoop.hbase.client.{Put, Result}
 import org.apache.hadoop.hbase.io.ImmutableBytesWritable
 import org.apache.hadoop.hbase.util.Bytes
+import org.apache.hadoop.hbase.KeyValue.Type
+import org.apache.hadoop.hbase.CellUtil
 
 /**
- * Implementation of [[org.apache.spark.api.python.Converter]] that converts an
- * HBase Result to a String
+ * Implementation of [[org.apache.spark.api.python.Converter]] that converts all
+ * the records in an HBase Result to a String
  */
 class HBaseResultToStringConverter extends Converter[Any, String] {
   override def convert(obj: Any): String = {
+    import collection.JavaConverters._
     val result = obj.asInstanceOf[Result]
-    Bytes.toStringBinary(result.value())
+    val output = result.listCells.asScala.map(cell =>
+        Map(
+          "row" -> Bytes.toStringBinary(CellUtil.cloneRow(cell)),
+          "columnFamily" -> Bytes.toStringBinary(CellUtil.cloneFamily(cell)),
+          "qualifier" -> Bytes.toStringBinary(CellUtil.cloneQualifier(cell)),
+          "timestamp" -> cell.getTimestamp.toString,
+          "type" -> Type.codeToType(cell.getTypeByte).toString,
+          "value" -> Bytes.toStringBinary(CellUtil.cloneValue(cell))
+        )
+    )
+    output.map(JSONObject(_).toString()).mkString("\n")
   }
 }