Package org.apache.hadoop.registry.client.binding

Class JsonSerDeser<T>

java.lang.Object

org.apache.hadoop.util.JsonSerialization<T>

org.apache.hadoop.registry.client.binding.JsonSerDeser<T>

Type Parameters:

T - Type to marshal.

Direct Known Subclasses:

RegistryUtils.ServiceRecordMarshal

@Private
@Evolving
public class JsonSerDeser<T>
extends org.apache.hadoop.util.JsonSerialization<T>

Support for marshalling objects to and from JSON.

This extends JsonSerialization with the notion of a marker field in the JSON file, with

1. a fail-fast check for it before even trying to parse.
2. Specific IOException subclasses for a failure.

The rationale for this is not only to support different things in the, registry, but the fact that all ZK nodes have a size > 0 when examined.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	E_DATA_TOO_SHORT
static java.lang.String	E_MISSING_MARKER_STRING
static java.lang.String	E_NO_DATA

Constructor Summary

Constructors

Constructor	Description
JsonSerDeser(java.lang.Class<T> classType)	Create an instance bound to a specific type

Method Summary

Modifier and Type	Method	Description
T	fromBytes(java.lang.String path, byte[] bytes)	Deserialize from a byte array
T	fromBytes(java.lang.String path, byte[] bytes, java.lang.String marker)	Deserialize from a byte array, optionally checking for a marker string.

Methods inherited from class org.apache.hadoop.util.JsonSerialization

fromBytes, fromInstance, fromJson, fromJsonStream, fromResource, getMapper, getName, load, load, load, mapReader, save, save, toBytes, toJson, toString, writeJsonAsBytes, writer

Methods inherited from class java.lang.Object

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

Field Detail

E_NO_DATA

public static final java.lang.String E_NO_DATA

See Also:

Constant Field Values

E_DATA_TOO_SHORT

public static final java.lang.String E_DATA_TOO_SHORT

See Also:

Constant Field Values

E_MISSING_MARKER_STRING

public static final java.lang.String E_MISSING_MARKER_STRING

See Also:

Constant Field Values

Constructor Detail

JsonSerDeser

public JsonSerDeser(java.lang.Class<T> classType)

Create an instance bound to a specific type

Parameters:

classType - class to marshall

Method Detail

fromBytes

public T fromBytes(java.lang.String path,
                   byte[] bytes)
            throws java.io.IOException

Deserialize from a byte array

Parameters:

path - path the data came from

bytes - byte array

Throws:

java.io.IOException - all problems

java.io.EOFException - not enough data

InvalidRecordException - if the parsing failed -the record is invalid

NoRecordException - if the data is not considered a record: either it is too short or it did not contain the marker string.

fromBytes

public T fromBytes(java.lang.String path,
                   byte[] bytes,
                   java.lang.String marker)
            throws java.io.IOException

Deserialize from a byte array, optionally checking for a marker string.

If the marker parameter is supplied (and not empty), then its presence will be verified before the JSON parsing takes place; it is a fast-fail check. If not found, an InvalidRecordException exception will be raised

Parameters:

path - path the data came from

bytes - byte array

marker - an optional string which, if set, MUST be present in the UTF-8 parsed payload.

Returns:

The parsed record

Throws:

java.io.IOException - all problems

java.io.EOFException - not enough data

InvalidRecordException - if the JSON parsing failed.

NoRecordException - if the data is not considered a record: either it is too short or it did not contain the marker string.