org.apache.slider.core.persist

Class JsonSerDeser<T>

java.lang.Object

org.apache.slider.core.persist.JsonSerDeser<T>

Type Parameters:

T -

Direct Known Subclasses:

AggregateConfSerDeser, ApplicationReportSerDeser, ConfTreeSerDeser

public class JsonSerDeser<T>
extends Object

Support for marshalling objects to and from JSON. This class is NOT thread safe; it constructs an object mapper as an instance field.

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
T	fromBytes(byte[] b) Deserialize from a byte array
T	fromFile(File jsonFile) Convert from a JSON file
T	fromInstance(T instance) clone by converting to JSON and back again.
T	fromJson(String json) Convert from JSON
T	fromResource(String resource) Convert from a JSON file
T	fromStream(InputStream stream) Convert from an input stream, closing the stream afterwards.
T	load(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path path) Load from a Hadoop filesystem
void	save(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path path, T instance, boolean overwrite) Save to a hadoop filesystem
void	save(T instance, File file) Save an instance to a file
String	toJson(T instance) Convert an object to a JSON string

Methods inherited from class java.lang.Object

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

Constructor Detail

JsonSerDeser

public JsonSerDeser(Class<T> classType)

Create an instance bound to a specific type

Parameters:

classType - class type

Method Detail

fromJson

public T fromJson(String json)
           throws IOException,
                  org.codehaus.jackson.JsonParseException,
                  org.codehaus.jackson.map.JsonMappingException

Convert from JSON

Parameters:

json - input

Returns:

the parsed JSON

Throws:

IOException - IO

org.codehaus.jackson.map.JsonMappingException - failure to map from the JSON to this class

org.codehaus.jackson.JsonParseException

fromFile

public T fromFile(File jsonFile)
           throws IOException,
                  org.codehaus.jackson.JsonParseException,
                  org.codehaus.jackson.map.JsonMappingException

Convert from a JSON file

Parameters:

jsonFile - input file

Returns:

the parsed JSON

Throws:

IOException - IO problems

org.codehaus.jackson.map.JsonMappingException - failure to map from the JSON to this class

org.codehaus.jackson.JsonParseException

fromResource

public T fromResource(String resource)
               throws IOException,
                      org.codehaus.jackson.JsonParseException,
                      org.codehaus.jackson.map.JsonMappingException

Convert from a JSON file

Parameters:

resource - input file

Returns:

the parsed JSON

Throws:

IOException - IO problems

org.codehaus.jackson.map.JsonMappingException - failure to map from the JSON to this class

org.codehaus.jackson.JsonParseException

fromStream

public T fromStream(InputStream stream)
             throws IOException

Convert from an input stream, closing the stream afterwards.

Parameters:

stream -

Returns:

the parsed JSON

Throws:

IOException - IO problems

fromInstance

public T fromInstance(T instance)
               throws IOException

clone by converting to JSON and back again. This is much less efficient than any Java clone process.

Parameters:

instance - instance to duplicate

Returns:

a new instance

Throws:

IOException - problems.

fromBytes

public T fromBytes(byte[] b)
            throws IOException

Deserialize from a byte array

Parameters:

b -

Returns:

the deserialized value

Throws:

IOException - parse problems

load

public T load(org.apache.hadoop.fs.FileSystem fs,
     org.apache.hadoop.fs.Path path)
       throws IOException,
              org.codehaus.jackson.JsonParseException,
              org.codehaus.jackson.map.JsonMappingException

Load from a Hadoop filesystem

Parameters:

fs - filesystem

path - path

Returns:

a loaded CD

Throws:

IOException - IO problems

org.codehaus.jackson.JsonParseException - parse problems

org.codehaus.jackson.map.JsonMappingException - O/J mapping problems

save

public void save(org.apache.hadoop.fs.FileSystem fs,
        org.apache.hadoop.fs.Path path,
        T instance,
        boolean overwrite)
          throws IOException

Save to a hadoop filesystem

Parameters:

fs - filesystem

path - path

instance - instance to save

overwrite - should any existing file be overwritten

Throws:

IOException - IO exception

save

public void save(T instance,
        File file)
          throws IOException

Save an instance to a file

Parameters:

instance - instance to save

file - file

Throws:

IOException

toJson

public String toJson(T instance)
              throws IOException,
                     org.codehaus.jackson.JsonGenerationException,
                     org.codehaus.jackson.map.JsonMappingException

Convert an object to a JSON string

Parameters:

instance - instance to convert

Returns:

a JSON string description

Throws:

org.codehaus.jackson.JsonParseException - parse problems

org.codehaus.jackson.map.JsonMappingException - O/J mapping problems

IOException

org.codehaus.jackson.JsonGenerationException