brickhouse.udf.json
Class FromJsonUDF

java.lang.Object
  org.apache.hadoop.hive.ql.udf.generic.GenericUDF
      brickhouse.udf.json.FromJsonUDF

public class FromJsonUDF
extends org.apache.hadoop.hive.ql.udf.generic.GenericUDF

Generate an arbitrary Hive structure from a JSON string, and an example template object. The UDF takes a JSON string as the first argument, and the second argument defines the return type of the UDF, and which fields are parsed from the JSON string. To parse JSON maps with values of varying types, use struct() to create a structure with the desired JSON keys. The template object should be constant. For example, from_json( " { "name":"Bob","value":23.0,colors["red","yellow","green"], "inner_map":{"a":1,"b":2,"c":3 }" , struct("name", "","value", 0.0,"colors", array(""), "inner_map", map("",1) );

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

org.apache.hadoop.hive.ql.udf.generic.GenericUDF.DeferredJavaObject, org.apache.hadoop.hive.ql.udf.generic.GenericUDF.DeferredObject

Constructor Summary

FromJsonUDF()

Method Summary

Object	evaluate(org.apache.hadoop.hive.ql.udf.generic.GenericUDF.DeferredObject[] arg0)
static String	FromCamelCase(String camel) Converts from CamelCase to a string containing underscores.
String	getDisplayString(String[] arg0)
org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector	initialize(org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector[] arg0)
static String	ToCamelCase(String underscore)

Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

getRequiredFiles, getRequiredJars, initializeAndFoldConstants

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FromJsonUDF

public FromJsonUDF()

Method Detail

evaluate

public Object evaluate(org.apache.hadoop.hive.ql.udf.generic.GenericUDF.DeferredObject[] arg0)
                throws org.apache.hadoop.hive.ql.metadata.HiveException

Specified by:

evaluate in class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

Throws:

org.apache.hadoop.hive.ql.metadata.HiveException

getDisplayString

public String getDisplayString(String[] arg0)

Specified by:

getDisplayString in class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

initialize

public org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector initialize(org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector[] arg0)
                                                                         throws org.apache.hadoop.hive.ql.exec.UDFArgumentException

Specified by:

initialize in class org.apache.hadoop.hive.ql.udf.generic.GenericUDF

Throws:

org.apache.hadoop.hive.ql.exec.UDFArgumentException

ToCamelCase

public static String ToCamelCase(String underscore)

FromCamelCase

public static String FromCamelCase(String camel)

Converts from CamelCase to a string containing underscores.

Parameters:

camel -

Returns: