com.basho.riak.client.operations

Class FetchObject<T>

java.lang.Object

com.basho.riak.client.operations.FetchObject<T>

All Implemented Interfaces:

RiakOperation<T>

public class FetchObject<T>
extends Object
implements RiakOperation<T>

An operation to get some data from Riak.

Use Bucket.fetch(String) methods to create a fetch operation. Also look at DomainBucket.fetch(Object).

Author:

russell

See Also:

Bucket, DomainBucket

Constructor Summary

Constructors

Constructor and Description
FetchObject(RawClient client, String bucket, String key, Retrier retrier) Create a new FetchOperation that delegates to the given client to fetch the data from bucket at key using retrier
FetchObject(RawClient client, String bucket, String key, Retrier retrier, FetchMeta fetchMeta) Create a new FetchOperation that delegates to the given client to fetch the data from bucket at key using retrier

Method Summary

Methods

Modifier and Type	Method and Description
FetchObject<T>	basicQuorum(boolean basicQuorum)
T	execute() Attempts to fetch the data at bucket/key, convert it with Converter and resolve any siblings with ConflictResolver
VClock	getVClock()
boolean	hasDeletedVclock() Deprecated.
boolean	hasVclock()
FetchObject<T>	headOnly() Causes the client to retrieve only the metadata and not the value of this object.
FetchObject<T>	ifModified(VClock vclock) *NOTE* PB Only.
boolean	isUnmodified()
FetchObject<T>	modifiedSince(Date modifiedSince) *NOTE* HTTP Only.
FetchObject<T>	notFoundOK(boolean notFoundOK)
FetchObject<T>	pr(int pr)
FetchObject<T>	pr(Quora pr)
FetchObject<T>	pr(Quorum pr)
FetchObject<T>	r(int r) The read quorum for this fetch operation
FetchObject<T>	r(Quora r) The read quorum for this fetch operation
FetchObject<T>	r(Quorum r) The read quorum for this fetch operation
FetchObject<T>	returnDeletedVClock(boolean returnDeletedVClock)
FetchObject<T>	timeout(int timeout) Set an operation timeout in milliseconds to be sent to Riak As of 1.4 Riak allows a timeout to be sent for get, put, and delete operations.
FetchObject<T>	withConverter(Converter<T> converter) A Converter to use to convert the data fetched to some other type
FetchObject<T>	withResolver(ConflictResolver<T> resolver)
FetchObject<T>	withRetrier(Retrier retrier) A Retrier to use

Methods inherited from class java.lang.Object

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

Constructor Detail

FetchObject

public FetchObject(RawClient client,
           String bucket,
           String key,
           Retrier retrier)

Create a new FetchOperation that delegates to the given client to fetch the data from bucket at key using retrier

Use Bucket to create a Fetch operation, also consider using DomainBucket

Parameters:

client - the RawClient to use for the operation

bucket - the name of the bucket to get the data item from

key - the name of the key to get the data item from

retrier - the Retrier to use when executing the operation.

FetchObject

public FetchObject(RawClient client,
           String bucket,
           String key,
           Retrier retrier,
           FetchMeta fetchMeta)

Create a new FetchOperation that delegates to the given client to fetch the data from bucket at key using retrier

Use Bucket to create a Fetch operation, also consider using DomainBucket

Parameters:

client - the RawClient to use for the operation

bucket - the name of the bucket to get the data item from

key - the name of the key to get the data item from

retrier - the Retrier to use when executing the operation.

fetchMeta - the FetchMeta to use when executing the operation

Method Detail

execute

public T execute()
          throws UnresolvedConflictException,
                 RiakRetryFailedException,
                 ConversionException

Attempts to fetch the data at bucket/key, convert it with Converter and resolve any siblings with ConflictResolver

Specified by:

execute in interface RiakOperation<T>

Returns:

an instance ofT that was stored at bucket/key or null if not found.

Throws:

UnresolvedConflictException - if the ConflictResolver used cannot get a single value from any siblings

RiakRetryFailedException - if the Retrier fails to execute the operation beyond some internal bound

ConversionException - if the supplied Converter throws trying to convert the retrieved value.

withResolver

public FetchObject<T> withResolver(ConflictResolver<T> resolver)

r

public FetchObject<T> r(int r)

The read quorum for this fetch operation

Parameters:

r - an Integer for the read quorum

Returns:

this

r

public FetchObject<T> r(Quora r)

The read quorum for this fetch operation

Parameters:

r - an Quora for the read quorum

Returns:

this

r

public FetchObject<T> r(Quorum r)

The read quorum for this fetch operation

Parameters:

r - an Quorum for the read quorum

Returns:

this

pr

public FetchObject<T> pr(int pr)

Parameters:

pr -

Returns:

See Also:

FetchMeta.Builder.pr(int)

pr

public FetchObject<T> pr(Quora pr)

Parameters:

pr -

Returns:

See Also:

FetchMeta.Builder.pr(Quora)

pr

public FetchObject<T> pr(Quorum pr)

Parameters:

pr -

Returns:

See Also:

FetchMeta.Builder.pr(Quora)

notFoundOK

public FetchObject<T> notFoundOK(boolean notFoundOK)

Parameters:

notFoundOK -

Returns:

See Also:

FetchMeta.Builder.notFoundOK(boolean)

basicQuorum

public FetchObject<T> basicQuorum(boolean basicQuorum)

Parameters:

basicQuorum -

Returns:

See Also:

FetchMeta.Builder.basicQuorum(boolean)

timeout

public FetchObject<T> timeout(int timeout)

Set an operation timeout in milliseconds to be sent to Riak As of 1.4 Riak allows a timeout to be sent for get, put, and delete operations. The client will receive a timeout error if the operation is not completed within the specified time

Parameters:

timeout - the timeout in milliseconds

Returns:

this

returnDeletedVClock

public FetchObject<T> returnDeletedVClock(boolean returnDeletedVClock)

Parameters:

returnDeletedVClock -

Returns:

See Also:

FetchMeta.Builder.returnDeletedVClock(boolean)

modifiedSince

public FetchObject<T> modifiedSince(Date modifiedSince)

*NOTE* HTTP Only. TODO using generics and transports make this generic Transport for either Date/VClock

Parameters:

modifiedSince - a last modified date.

Returns:

this

ifModified

public FetchObject<T> ifModified(VClock vclock)

*NOTE* PB Only. TODO using generics and transports make this generic T for either Date/VClock

Parameters:

vclock - a vclock

Returns:

this

headOnly

public FetchObject<T> headOnly()

Causes the client to retrieve only the metadata and not the value of this object. Note if you are using HTTP If siblings are present the client does a second get and retrieves all the values. This is due to how the HTTP API handles siblings. Note: The Converter being used must be able to handle an empty value.

Returns:

this

See Also:

FetchMeta.Builder.headOnly(boolean headOnly)

withConverter

public FetchObject<T> withConverter(Converter<T> converter)

A Converter to use to convert the data fetched to some other type

Parameters:

converter -

Returns:

this

withRetrier

public FetchObject<T> withRetrier(Retrier retrier)

A Retrier to use

Parameters:

retrier -

Returns:

isUnmodified

public boolean isUnmodified()

Returns:

true if the fetch was conditional and no result was returned since the value was unmodified

hasDeletedVclock

@Deprecated
public boolean hasDeletedVclock()

Deprecated.

Returns:

true if the fetch was to a deleted key but the returnDeletedVClock parameter was set, and the response has that vclock

See Also:

IRiakObject#isDeleted() }

hasVclock

public boolean hasVclock()

Returns:

checks that the response had a vclock (i.e. was some kind of success)

getVClock

public VClock getVClock()

Returns:

if hasDeletedVclock or hasVclock return true, this method returns the vclock