public final class DataTypeUtilsDataTypeUtils 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),
- All numeric primitive wrappers (Byte through Long, Float and Double, but not java.math.BigInteger or java.math.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.
Static Fields
MAX_LINK_PROPERTY_LENGTH
public static final int MAX_LINK_PROPERTY_LENGTH| Field Value | |
|---|---|
| Type | Description |
int |
|
MAX_SHORT_BLOB_PROPERTY_LENGTH
public static final int MAX_SHORT_BLOB_PROPERTY_LENGTHThis is the maximum number of bytes that a ShortBlob property can contain. If your data
is larger, you need to use a Blob.
| Field Value | |
|---|---|
| Type | Description |
int |
|
MAX_STRING_PROPERTY_LENGTH
public static final int MAX_STRING_PROPERTY_LENGTHThis is the maximum number of bytes that a string property can contain. If your string has more bytes, you need to wrap it in a Text.
| Field Value | |
|---|---|
| Type | Description |
int |
|
Static Methods
checkSupportedValue(@Nullable String name, @Nullable Object value)
public static void checkSupportedValue(@Nullable String name, @Nullable Object value)If the specified object cannot be used as the value for a Entity property, throw an
exception with the appropriate explanation.
| Parameters | |
|---|---|
| Name | Description |
name |
Nullable String |
value |
Nullable Object |
checkSupportedValue(Object value)
public static void checkSupportedValue(Object value)If the specified object cannot be used as the value for a Entity property, throw an
exception with the appropriate explanation.
| Parameter | |
|---|---|
| Name | Description |
value |
Object |
getSupportedTypes()
public static Set<Class<?>> getSupportedTypes()Returns an unmodifiable Set of supported Class objects.
| Returns | |
|---|---|
| Type | Description |
Set<Class<?>> |
|
isSupportedType(Class<?> clazz)
public static boolean isSupportedType(Class<?> clazz)Returns true if and only if the supplied Class can be stored in the data store.
| Parameter | |
|---|---|
| Name | Description |
clazz |
Class<?> |
| Returns | |
|---|---|
| Type | Description |
boolean |
|
isUnindexableType(Class<?> clazz)
public static boolean isUnindexableType(Class<?> clazz)Returns true if the supplied Class cannot be indexed.
| Parameter | |
|---|---|
| Name | Description |
clazz |
Class<?> |
| Returns | |
|---|---|
| Type | Description |
boolean |
|