JDBCFeatureSource (Geotools modules 21.0 API)

Object
- ContentFeatureSource
- - JDBCFeatureSource

All Implemented Interfaces:

FeatureSource<SimpleFeatureType,SimpleFeature>, SimpleFeatureSource

Direct Known Subclasses:

JoiningJDBCFeatureSource
```
public class JDBCFeatureSource
extends ContentFeatureSource
```

Field Summary
- Fields inherited from class ContentFeatureSource
  entry, hints, lock, query, queryCapabilities, schema, transaction

Constructor Summary

Constructors
Modifier	Constructor and Description
	`JDBCFeatureSource(ContentEntry entry, Query query)` Creates the new feature store.
`protected`	`JDBCFeatureSource(JDBCFeatureSource featureSource)` Copy existing feature source

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`addHints(Set<Hints.Key> hints)` Subclass hook too add additional hints.
`protected SimpleFeatureType`	`buildFeatureType()` Builds the feature type from database metadata.
`protected QueryCapabilities`	`buildQueryCapabilities()` Builds the query capabilities for this feature source.
`protected boolean`	`canFilter()` Determines if the datastore can natively perform a filtering.
`protected boolean`	`canLimit()` Determines if the datastore can natively limit the number of features returned in a query.
`protected boolean`	`canOffset()` Determines if the datastore can natively skip the first `offset` number of features returned in a query.
`protected boolean`	`canRetype()` Determines if the datasatore can natively perform "retyping" which includes limiting the number of attributes returned and reordering of those attributes If the subclass can handle retyping natively it should override this method to return `true`.
`protected boolean`	`canSort()` Determines if the datastore can natively perform sorting.
`protected boolean`	`canTransact()` Determines if the store can natively manage transactions.
`protected ReferencedEnvelope`	`getBoundsInternal(Query query)` Calculates the bounds of a specified query.
`protected int`	`getCountInternal(Query query)` Calculates the number of features of a specified query.
`JDBCDataStore`	`getDataStore()` Type narrow to `JDBCDataStore`.
`PrimaryKey`	`getPrimaryKey()` Returns the primary key of the table backed by feature store.
`protected FeatureReader<SimpleFeatureType,SimpleFeature>`	`getReaderInternal(Query query)` Subclass method for returning a native reader from the datastore.
`JDBCState`	`getState()` Type narrow to `JDBCState`.
`protected boolean`	`handleVisitor(Query query, FeatureVisitor visitor)` Subclass method which allows subclasses to natively handle a visitor.
`boolean`	`isExposePrimaryKeyColumns()` The flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.
`void`	`setExposePrimaryKeyColumns(boolean exposePrimaryKeyColumns)` Sets the flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - JDBCFeatureSource
```
public JDBCFeatureSource(ContentEntry entry,
                         Query query)
                  throws IOException
```
    Creates the new feature store.
    
    Parameters:
    
    entry - The datastore entry.
    
    query - The defining query.
    
    Throws:
    
    IOException
  - JDBCFeatureSource
```
protected JDBCFeatureSource(JDBCFeatureSource featureSource)
                     throws IOException
```
    Copy existing feature source
    
    Parameters:
    
    featureSource - jdbc feature source
    
    Throws:
    
    IOException
- Method Detail
  - buildQueryCapabilities
```
protected QueryCapabilities buildQueryCapabilities()
```
    Description copied from class: ContentFeatureSource
    
    Builds the query capabilities for this feature source. The default implementation returns a newly built QueryCapabilities, subclasses are advised to build their own.
    
    Overrides:
    
    buildQueryCapabilities in class ContentFeatureSource
    
    Returns:
  - addHints
```
protected void addHints(Set<Hints.Key> hints)
```
    Description copied from class: ContentFeatureSource
    Subclass hook too add additional hints.
    By default, the followings are already present:
    - Hints.JTS_COORDINATE_SEQUENCE_FACTORY
    - Hints.JTS_GEOMETRY_FACTORY
    Overrides:
    
    addHints in class ContentFeatureSource
    
    Parameters:
    
    hints - The set of hints supported by the feature source.
  - getDataStore
```
public JDBCDataStore getDataStore()
```
    Type narrow to JDBCDataStore.
    
    Specified by:
    
    getDataStore in interface FeatureSource<SimpleFeatureType,SimpleFeature>
    
    Overrides:
    
    getDataStore in class ContentFeatureSource
    
    Returns:
    
    the data source providing this FeatureSource
  - getState
```
public JDBCState getState()
```
    Type narrow to JDBCState.
    
    Overrides:
    
    getState in class ContentFeatureSource
    
    See Also:
    
    #setTransaction(Transaction)}.
  - getPrimaryKey
```
public PrimaryKey getPrimaryKey()
```
    Returns the primary key of the table backed by feature store.
  - setExposePrimaryKeyColumns
```
public void setExposePrimaryKeyColumns(boolean exposePrimaryKeyColumns)
```
    Sets the flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.
    Note: setting this flag which affect all feature sources created from or working against the current transaction.
  - isExposePrimaryKeyColumns
```
public boolean isExposePrimaryKeyColumns()
```
    The flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.
  - buildFeatureType
```
protected SimpleFeatureType buildFeatureType()
                                      throws IOException
```
    Builds the feature type from database metadata.
    
    Specified by:
    
    buildFeatureType in class ContentFeatureSource
    
    Throws:
    
    IOException
  - getCountInternal
```
protected int getCountInternal(Query query)
                        throws IOException
```
    Description copied from class: ContentFeatureSource
    
    Calculates the number of features of a specified query. Subclasses must implement this method.
    
    Specified by:
    
    getCountInternal in class ContentFeatureSource
    
    Throws:
    
    IOException
  - getBoundsInternal
```
protected ReferencedEnvelope getBoundsInternal(Query query)
                                        throws IOException
```
    Description copied from class: ContentFeatureSource
    
    Calculates the bounds of a specified query. Subclasses must implement this method.
    
    Specified by:
    
    getBoundsInternal in class ContentFeatureSource
    
    Throws:
    
    IOException
  - canFilter
```
protected boolean canFilter()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the datastore can natively perform a filtering.
    If the subclass can handle filtering natively it should override this method to return true. In this case it must do the filtering or throw an exception. This includes the case of partial native filtering where the datastore can only handle part of the filter natively. In these cases it is up to the subclass to apply a decorator to the reader it returns which will handle any part of the filter can was not applied natively. See FilteringFeatureReader.
    Not overriding this method or returning false will cause the feature reader created by the subclass to be wrapped in a filtering feature reader when the query specifies a filter. See FilteringFeatureReader.
    
    Overrides:
    
    canFilter in class ContentFeatureSource
  - canSort
```
protected boolean canSort()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the datastore can natively perform sorting.
    If the subclass can handle retyping natively it should override this method to return true. In this case it must do the retyping or throw an exception.
    Not overriding this method or returning false will cause an exception to be thrown when the query specifies sorting.
    
    Overrides:
    
    canSort in class ContentFeatureSource
    
    See Also:
    
    SortedFeatureReader
  - canRetype
```
protected boolean canRetype()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the datasatore can natively perform "retyping" which includes limiting the number of attributes returned and reordering of those attributes
    If the subclass can handle retyping natively it should override this method to return true. In this case it must do the retyping or throw an exception.
    Not overriding this method or returning false will cause the feature reader created by the subclass to be wrapped in a retyping feature reader when the query specifies a retype.
    
    Overrides:
    
    canRetype in class ContentFeatureSource
    
    See Also:
    
    ReTypeFeatureReader
  - canLimit
```
protected boolean canLimit()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the datastore can natively limit the number of features returned in a query.
    If the subclass can handle a map feature cap natively then it should override this method to return true. In this case it must do the cap or throw an exception.
    Not overriding this method or returning false will case the feature reader created by the subclass to be wrapped in a max feature capping decorator when the query specifies a max feature cap.
    
    Overrides:
    
    canLimit in class ContentFeatureSource
    
    See Also:
    
    MaxFeatureReader
  - canOffset
```
protected boolean canOffset()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the datastore can natively skip the first offset number of features returned in a query.
    If the subclass can handle a map feature cap natively then it should override this method to return true. In this case it must do the cap or throw an exception.
    Not overriding this method or returning false will case the feature reader created by the subclass to be be accesset offset times before being returned to the caller.
    
    Overrides:
    
    canOffset in class ContentFeatureSource
  - canTransact
```
protected boolean canTransact()
```
    Description copied from class: ContentFeatureSource
    
    Determines if the store can natively manage transactions.
    If a subclass can handle transactions natively it should override this method to return true and deal with transactions on its own, including firing feature modifications events.
    
    Overrides:
    
    canTransact in class ContentFeatureSource
    
    Returns:
    
    true if transaction independence has custom implementation
  - getReaderInternal
```
protected FeatureReader<SimpleFeatureType,SimpleFeature> getReaderInternal(Query query)
                                                                    throws IOException
```
    Description copied from class: ContentFeatureSource
    Subclass method for returning a native reader from the datastore.
    It is important to note that if the native reader intends to handle any of the following natively:
    - reprojection
    - filtering
    - max feature limiting
    - sorting
    - locking
    - transactions
    Then it *must* set the corresponding flags to true:
    - ContentFeatureSource.canReproject() - handles Query.getCoordinateSystemReproject() internally. Example would be PostGIS using Proj to handle reproejction internally
    - ContentFeatureSource.canFilter() - handles Query#getFilter() internally.
    - {@link #canLimit()} - handles {@link Query#getMaxFeatures()} and {@link Query#getStartIndex()} internally.
    - {@link #canSort()} - handles {@link Query#getSortBy()} natively.
    - {@link #canRetype()} - handles {@link Query#getProperties()} natively. Example would be only parsing the properties the user asks for from an XML file
    - {@link #canLock()} - handles read-locks natively
    - {@link #canTransact()} - handles transactions natively
    Specified by:
    
    getReaderInternal in class ContentFeatureSource
    
    Throws:
    
    IOException
  - handleVisitor
```
protected boolean handleVisitor(Query query,
                                FeatureVisitor visitor)
                         throws IOException
```
    Description copied from class: ContentFeatureSource
    
    Subclass method which allows subclasses to natively handle a visitor.
    Subclasses would override this method and return true in cases where the specific visitor could be handled without iterating over the entire result set of query. An example would be handling visitors that calculate aggregate values.
    
    Overrides:
    
    handleVisitor in class ContentFeatureSource
    
    Parameters:
    
    query - The query being made.
    
    visitor - The visitor to
    
    Returns:
    
    true if the visitor can be handled natively, otherwise false.
    
    Throws:
    
    IOException

Class JDBCFeatureSource

Field Summary

Fields inherited from class ContentFeatureSource

Constructor Summary

Method Summary

Methods inherited from class ContentFeatureSource

Methods inherited from class Object

Constructor Detail

JDBCFeatureSource

JDBCFeatureSource

Method Detail

buildQueryCapabilities

addHints

getDataStore

getState

getPrimaryKey

setExposePrimaryKeyColumns

isExposePrimaryKeyColumns

buildFeatureType

getCountInternal

getBoundsInternal

canFilter

canSort

canRetype

canLimit

canOffset

canTransact

getReaderInternal

handleVisitor