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CursorWindow

public class CursorWindow
extends SQLiteClosable implements Parcelable

java.lang.Object
   ↳ android.database.sqlite.SQLiteClosable
     ↳ android.database.CursorWindow


A buffer containing multiple cursor rows.

A CursorWindow is read-write when initially created and used locally. When sent to a remote process (by writing it to a Parcel), the remote process receives a read-only view of the cursor window. Typically the cursor window will be allocated by the producer, filled with data, and then sent to the consumer for reading.

Summary

Inherited constants

Fields

public static final Creator<CursorWindow> CREATOR

Public constructors

CursorWindow(String name)

Creates a new empty cursor window and gives it a name.

CursorWindow(String name, long windowSizeBytes)

Creates a new empty cursor window and gives it a name.

CursorWindow(boolean localWindow)

This constructor is deprecated. There is no longer a distinction between local and remote cursor windows. Use the CursorWindow(java.lang.String) constructor instead.

Public methods

boolean allocRow()

Allocates a new row at the end of this cursor window.

void clear()

Clears out the existing contents of the window, making it safe to reuse for new data.

void copyStringToBuffer(int row, int column, CharArrayBuffer buffer)

Copies the text of the field at the specified row and column index into a CharArrayBuffer.

int describeContents()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.

void freeLastRow()

Frees the last row in this cursor window.

byte[] getBlob(int row, int column)

Gets the value of the field at the specified row and column index as a byte array.

double getDouble(int row, int column)

Gets the value of the field at the specified row and column index as a double.

float getFloat(int row, int column)

Gets the value of the field at the specified row and column index as a float.

int getInt(int row, int column)

Gets the value of the field at the specified row and column index as an int.

long getLong(int row, int column)

Gets the value of the field at the specified row and column index as a long.

int getNumRows()

Gets the number of rows in this window.

short getShort(int row, int column)

Gets the value of the field at the specified row and column index as a short.

int getStartPosition()

Gets the start position of this cursor window.

String getString(int row, int column)

Gets the value of the field at the specified row and column index as a string.

int getType(int row, int column)

Returns the type of the field at the specified row and column index.

boolean isBlob(int row, int column)

This method is deprecated. Use getType(int, int) instead.

boolean isFloat(int row, int column)

This method is deprecated. Use getType(int, int) instead.

boolean isLong(int row, int column)

This method is deprecated. Use getType(int, int) instead.

boolean isNull(int row, int column)

This method is deprecated. Use getType(int, int) instead.

boolean isString(int row, int column)

This method is deprecated. Use getType(int, int) instead.

static CursorWindow newFromParcel(Parcel p)
boolean putBlob(byte[] value, int row, int column)

Copies a byte array into the field at the specified row and column index.

boolean putDouble(double value, int row, int column)

Puts a double-precision floating point value into the field at the specified row and column index.

boolean putLong(long value, int row, int column)

Puts a long integer into the field at the specified row and column index.

boolean putNull(int row, int column)

Puts a null value into the field at the specified row and column index.

boolean putString(String value, int row, int column)

Copies a string into the field at the specified row and column index.

boolean setNumColumns(int columnNum)

Sets the number of columns in this window.

void setStartPosition(int pos)

Sets the start position of this cursor window.

String toString()

Returns a string representation of the object.

void writeToParcel(Parcel dest, int flags)

Flatten this object in to a Parcel.

Protected methods

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

void onAllReferencesReleased()

Called when the last reference to the object was released by a call to releaseReference() or close().

Inherited methods

Fields

CREATOR

public static final Creator<CursorWindow> CREATOR

Public constructors

CursorWindow

public CursorWindow (String name)

Creates a new empty cursor window and gives it a name.

The cursor initially has no rows or columns. Call setNumColumns(int) to set the number of columns before adding any rows to the cursor.

Parameters
name String: The name of the cursor window, or null if none.

CursorWindow

public CursorWindow (String name, 
                long windowSizeBytes)

Creates a new empty cursor window and gives it a name.

The cursor initially has no rows or columns. Call setNumColumns(int) to set the number of columns before adding any rows to the cursor.

Parameters
name String: The name of the cursor window, or null if none.

windowSizeBytes long: Size of cursor window in bytes.

Note: Memory is dynamically allocated as data rows are added to the window. Depending on the amount of data stored, the actual amount of memory allocated can be lower than specified size, but cannot exceed it. Value is a non-negative number of bytes.

CursorWindow

public CursorWindow (boolean localWindow)

This constructor is deprecated.
There is no longer a distinction between local and remote cursor windows. Use the CursorWindow(java.lang.String) constructor instead.

Creates a new empty cursor window.

The cursor initially has no rows or columns. Call setNumColumns(int) to set the number of columns before adding any rows to the cursor.

Parameters
localWindow boolean: True if this window will be used in this process only, false if it might be sent to another processes. This argument is ignored.

Public methods

allocRow

public boolean allocRow ()

Allocates a new row at the end of this cursor window.

Returns
boolean True if successful, false if the cursor window is out of memory.

clear

public void clear ()

Clears out the existing contents of the window, making it safe to reuse for new data.

The start position (getStartPosition()), number of rows (getNumRows()), and number of columns in the cursor are all reset to zero.

copyStringToBuffer

public void copyStringToBuffer (int row, 
                int column, 
                CharArrayBuffer buffer)

Copies the text of the field at the specified row and column index into a CharArrayBuffer.

The buffer is populated as follows:

  • If the buffer is too small for the value to be copied, then it is automatically resized.
  • If the field is of type Cursor#FIELD_TYPE_NULL, then the buffer is set to an empty string.
  • If the field is of type Cursor#FIELD_TYPE_STRING, then the buffer is set to the contents of the string.
  • If the field is of type Cursor#FIELD_TYPE_INTEGER, then the buffer is set to a string representation of the integer in decimal, obtained by formatting the value with the printf family of functions using format specifier %lld.
  • If the field is of type Cursor#FIELD_TYPE_FLOAT, then the buffer is set to a string representation of the floating-point value in decimal, obtained by formatting the value with the printf family of functions using format specifier %g.
  • If the field is of type Cursor#FIELD_TYPE_BLOB, then a SQLiteException is thrown.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

buffer CharArrayBuffer: The CharArrayBuffer to hold the string. It is automatically resized if the requested string is larger than the buffer's current capacity.

describeContents

public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Returns
int a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or CONTENTS_FILE_DESCRIPTOR

freeLastRow

public void freeLastRow ()

Frees the last row in this cursor window.

getBlob

public byte[] getBlob (int row, 
                int column)

Gets the value of the field at the specified row and column index as a byte array.

The result is determined as follows:

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
byte[] The value of the field as a byte array.

getDouble

public double getDouble (int row, 
                int column)

Gets the value of the field at the specified row and column index as a double.

The result is determined as follows:

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
double The value of the field as a double.

getFloat

public float getFloat (int row, 
                int column)

Gets the value of the field at the specified row and column index as a float.

The result is determined by invoking getDouble(int, int) and converting the result to float.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
float The value of the field as an float.

getInt

public int getInt (int row, 
                int column)

Gets the value of the field at the specified row and column index as an int.

The result is determined by invoking getLong(int, int) and converting the result to int.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
int The value of the field as an int.

getLong

public long getLong (int row, 
                int column)

Gets the value of the field at the specified row and column index as a long.

The result is determined as follows:

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
long The value of the field as a long.

getNumRows

public int getNumRows ()

Gets the number of rows in this window.

Returns
int The number of rows in this cursor window. Value is 0 or greater

getShort

public short getShort (int row, 
                int column)

Gets the value of the field at the specified row and column index as a short.

The result is determined by invoking getLong(int, int) and converting the result to short.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
short The value of the field as a short.

getStartPosition

public int getStartPosition ()

Gets the start position of this cursor window.

The start position is the zero-based index of the first row that this window contains relative to the entire result set of the Cursor.

Returns
int The zero-based start position. Value is 0 or greater

getString

public String getString (int row, 
                int column)

Gets the value of the field at the specified row and column index as a string.

The result is determined as follows:

  • If the field is of type Cursor#FIELD_TYPE_NULL, then the result is null.
  • If the field is of type Cursor#FIELD_TYPE_STRING, then the result is the string value.
  • If the field is of type Cursor#FIELD_TYPE_INTEGER, then the result is a string representation of the integer in decimal, obtained by formatting the value with the printf family of functions using format specifier %lld.
  • If the field is of type Cursor#FIELD_TYPE_FLOAT, then the result is a string representation of the floating-point value in decimal, obtained by formatting the value with the printf family of functions using format specifier %g.
  • If the field is of type Cursor#FIELD_TYPE_BLOB, then a SQLiteException is thrown.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
String The value of the field as a string.

getType

public int getType (int row, 
                int column)

Returns the type of the field at the specified row and column index.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
int The field type. Value is Cursor.FIELD_TYPE_NULL, Cursor.FIELD_TYPE_INTEGER, Cursor.FIELD_TYPE_FLOAT, Cursor.FIELD_TYPE_STRING, or Cursor.FIELD_TYPE_BLOB

isBlob

public boolean isBlob (int row, 
                int column)

This method is deprecated.
Use getType(int, int) instead.

Returns true if the field at the specified row and column index has type Cursor#FIELD_TYPE_BLOB or Cursor#FIELD_TYPE_NULL.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if the field has type Cursor#FIELD_TYPE_BLOB or Cursor#FIELD_TYPE_NULL.

isFloat

public boolean isFloat (int row, 
                int column)

This method is deprecated.
Use getType(int, int) instead.

Returns true if the field at the specified row and column index has type Cursor#FIELD_TYPE_FLOAT.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if the field has type Cursor#FIELD_TYPE_FLOAT.

isLong

public boolean isLong (int row, 
                int column)

This method is deprecated.
Use getType(int, int) instead.

Returns true if the field at the specified row and column index has type Cursor#FIELD_TYPE_INTEGER.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if the field has type Cursor#FIELD_TYPE_INTEGER.

isNull

public boolean isNull (int row, 
                int column)

This method is deprecated.
Use getType(int, int) instead.

Returns true if the field at the specified row and column index has type Cursor#FIELD_TYPE_NULL.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if the field has type Cursor#FIELD_TYPE_NULL.

isString

public boolean isString (int row, 
                int column)

This method is deprecated.
Use getType(int, int) instead.

Returns true if the field at the specified row and column index has type Cursor#FIELD_TYPE_STRING or Cursor#FIELD_TYPE_NULL.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if the field has type Cursor#FIELD_TYPE_STRING or Cursor#FIELD_TYPE_NULL.

newFromParcel

public static CursorWindow newFromParcel (Parcel p)

Parameters
p Parcel

Returns
CursorWindow

putBlob

public boolean putBlob (byte[] value, 
                int row, 
                int column)

Copies a byte array into the field at the specified row and column index.

Parameters
value byte: The value to store.

row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if successful.

putDouble

public boolean putDouble (double value, 
                int row, 
                int column)

Puts a double-precision floating point value into the field at the specified row and column index.

Parameters
value double: The value to store.

row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if successful.

putLong

public boolean putLong (long value, 
                int row, 
                int column)

Puts a long integer into the field at the specified row and column index.

Parameters
value long: The value to store.

row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if successful.

putNull

public boolean putNull (int row, 
                int column)

Puts a null value into the field at the specified row and column index.

Parameters
row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if successful.

putString

public boolean putString (String value, 
                int row, 
                int column)

Copies a string into the field at the specified row and column index.

Parameters
value String: The value to store.

row int: The zero-based row index. Value is 0 or greater

column int: The zero-based column index. Value is 0 or greater

Returns
boolean True if successful.

setNumColumns

public boolean setNumColumns (int columnNum)

Sets the number of columns in this window.

This method must be called before any rows are added to the window, otherwise it will fail to set the number of columns if it differs from the current number of columns.

Parameters
columnNum int: The new number of columns. Value is 0 or greater

Returns
boolean True if successful.

setStartPosition

public void setStartPosition (int pos)

Sets the start position of this cursor window.

The start position is the zero-based index of the first row that this window contains relative to the entire result set of the Cursor.

Parameters
pos int: The new zero-based start position. Value is 0 or greater

toString

public String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

Returns
String a string representation of the object.

writeToParcel

public void writeToParcel (Parcel dest, 
                int flags)

Flatten this object in to a Parcel.

Parameters
dest Parcel: The Parcel in which the object should be written.

flags int: Additional flags about how the object should be written. May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES

Protected methods

finalize

protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java™ virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.

Throws
Throwable

onAllReferencesReleased

protected void onAllReferencesReleased ()

Called when the last reference to the object was released by a call to releaseReference() or close().