public final class DataTypeUtils
extends java.lang.Object
DataTypeUtils
presents a simpler interface that allows
user-code to determine what Classes can safely be stored as
properties in the data store.
Currently this list includes:
String
(but not
StringBuffer
),
Byte
through
Long
,
Float
and
Double
, but not
BigInteger
or
BigDecimal
.
Key
, for storing references to other
Entity
objects.
User
, for storing references to users.
ShortBlob
, for storing binary data small enough to be indexed.
This means properties of this type, unlike
Blob
properties, can be
filtered and sorted on in queries.
Blob
, for storing unindexed binary data less than 1MB.
Text
, for storing unindexed String data less than 1MB.
BlobKey
, for storing references to user uploaded
blobs (which may exceed 1MB).
Date
.
Link
.
Modifier and Type | Field and Description |
---|---|
static int
|
MAX_LINK_PROPERTY_LENGTH
|
static int
|
MAX_SHORT_BLOB_PROPERTY_LENGTH
This is the maximum number of bytes that a
ShortBlob
property
can contain.
|
static int
|
MAX_STRING_PROPERTY_LENGTH
This is the maximum number of characters that a string property
can contain.
|
Modifier and Type | Method and Description |
---|---|
static void
|
checkSupportedValue
(java.lang.Object value)
If the specified object cannot be used as the value for a
Entity
property, throw an exception with the appropriate
explanation.
|
static void
|
checkSupportedValue
(java.lang.String name,
java.lang.Object value)
If the specified object cannot be used as the value for a
Entity
property, throw an exception with the appropriate
explanation.
|
static java.util.Set<java.lang.Class<?>>
|
getSupportedTypes
()
Returns an unmodifiable
Set
of supported
Class
objects.
|
static boolean
|
isSupportedType
(java.lang.Class<?> clazz)
Returns true if and only if the supplied
Class
can be
stored in the data store.
|
public static final int MAX_STRING_PROPERTY_LENGTH
Text
.
public static final int MAX_SHORT_BLOB_PROPERTY_LENGTH
ShortBlob
property
can contain. If your data is larger, you need to use a
Blob
.
public static final int MAX_LINK_PROPERTY_LENGTH
public static void checkSupportedValue(java.lang.Object value)
Entity
property, throw an exception with the appropriate
explanation.
java.lang.NullPointerException
- if the specified value is null
java.lang.IllegalArgumentException
- if the type is not supported, or
if the object is in some other way invalid.
public static void checkSupportedValue(java.lang.String name, java.lang.Object value)
Entity
property, throw an exception with the appropriate
explanation.
java.lang.NullPointerException
- if the specified value is null
java.lang.IllegalArgumentException
- if the type is not supported, or
if the object is in some other way invalid.
public static boolean isSupportedType(java.lang.Class<?> clazz)
Class
can be
stored in the data store.
public static java.util.Set<java.lang.Class<?>> getSupportedTypes()
Set
of supported
Class
objects.