FileDocCategorySizeDatePackage
SQLiteCursor.javaAPI DocAndroid 5.1 API9494Thu Mar 12 22:22:10 GMT 2015android.database.sqlite

SQLiteCursor

public class SQLiteCursor extends android.database.AbstractWindowedCursor
A Cursor implementation that exposes results from a query on a {@link SQLiteDatabase}. SQLiteCursor is not internally synchronized so code using a SQLiteCursor from multiple threads should perform its own synchronization when using the SQLiteCursor.

Fields Summary
static final String
TAG
static final int
NO_COUNT
private final String
mEditTable
The name of the table to edit
private final String[]
mColumns
The names of the columns in the rows
private final SQLiteQuery
mQuery
The query object for the cursor
private final SQLiteCursorDriver
mDriver
The compiled query this cursor came from
private int
mCount
The number of rows in the cursor
private int
mCursorWindowCapacity
The number of rows that can fit in the cursor window, 0 if unknown
private Map
mColumnNameMap
A mapping of column names to column indices, to speed up lookups
private final Throwable
mStackTrace
Used to find out where a cursor was allocated in case it never got released.
Constructors Summary
public SQLiteCursor(SQLiteDatabase db, SQLiteCursorDriver driver, String editTable, SQLiteQuery query)
Execute a query and provide access to its result set through a Cursor interface. For a query such as: {@code SELECT name, birth, phone FROM myTable WHERE ... LIMIT 1,20 ORDER BY...} the column names (name, birth, phone) would be in the projection argument and everything from {@code FROM} onward would be in the params argument.

param
db a reference to a Database object that is already constructed and opened. This param is not used any longer
param
editTable the name of the table used for this query
param
query the rest of the query terms cursor is finalized
deprecated
use {@link #SQLiteCursor(SQLiteCursorDriver, String, SQLiteQuery)} instead


                                                                                                                           
    
        
                
        this(driver, editTable, query);
public SQLiteCursor(SQLiteCursorDriver driver, String editTable, SQLiteQuery query)
Execute a query and provide access to its result set through a Cursor interface. For a query such as: {@code SELECT name, birth, phone FROM myTable WHERE ... LIMIT 1,20 ORDER BY...} the column names (name, birth, phone) would be in the projection argument and everything from {@code FROM} onward would be in the params argument.

param
editTable the name of the table used for this query
param
query the {@link SQLiteQuery} object associated with this cursor object.

        if (query == null) {
            throw new IllegalArgumentException("query object cannot be null");
        }
        if (StrictMode.vmSqliteObjectLeaksEnabled()) {
            mStackTrace = new DatabaseObjectNotClosedException().fillInStackTrace();
        } else {
            mStackTrace = null;
        }
        mDriver = driver;
        mEditTable = editTable;
        mColumnNameMap = null;
        mQuery = query;

        mColumns = query.getColumnNames();
        mRowIdColumnIndex = DatabaseUtils.findRowIdColumnIndex(mColumns);
Methods Summary
public voidclose()

        super.close();
        synchronized (this) {
            mQuery.close();
            mDriver.cursorClosed();
        }
public voiddeactivate()

        super.deactivate();
        mDriver.cursorDeactivated();
private voidfillWindow(int requiredPos)

        clearOrCreateWindow(getDatabase().getPath());

        try {
            if (mCount == NO_COUNT) {
                int startPos = DatabaseUtils.cursorPickFillWindowStartPosition(requiredPos, 0);
                mCount = mQuery.fillWindow(mWindow, startPos, requiredPos, true);
                mCursorWindowCapacity = mWindow.getNumRows();
                if (Log.isLoggable(TAG, Log.DEBUG)) {
                    Log.d(TAG, "received count(*) from native_fill_window: " + mCount);
                }
            } else {
                int startPos = DatabaseUtils.cursorPickFillWindowStartPosition(requiredPos,
                        mCursorWindowCapacity);
                mQuery.fillWindow(mWindow, startPos, requiredPos, false);
            }
        } catch (RuntimeException ex) {
            // Close the cursor window if the query failed and therefore will
            // not produce any results.  This helps to avoid accidentally leaking
            // the cursor window if the client does not correctly handle exceptions
            // and fails to close the cursor.
            closeWindow();
            throw ex;
        }
protected voidfinalize()
Release the native resources, if they haven't been released yet.

        try {
            // if the cursor hasn't been closed yet, close it first
            if (mWindow != null) {
                if (mStackTrace != null) {
                    String sql = mQuery.getSql();
                    int len = sql.length();
                    StrictMode.onSqliteObjectLeaked(
                        "Finalizing a Cursor that has not been deactivated or closed. " +
                        "database = " + mQuery.getDatabase().getLabel() +
                        ", table = " + mEditTable +
                        ", query = " + sql.substring(0, (len > 1000) ? 1000 : len),
                        mStackTrace);
                }
                close();
            }
        } finally {
            super.finalize();
        }
public intgetColumnIndex(java.lang.String columnName)

        // Create mColumnNameMap on demand
        if (mColumnNameMap == null) {
            String[] columns = mColumns;
            int columnCount = columns.length;
            HashMap<String, Integer> map = new HashMap<String, Integer>(columnCount, 1);
            for (int i = 0; i < columnCount; i++) {
                map.put(columns[i], i);
            }
            mColumnNameMap = map;
        }

        // Hack according to bug 903852
        final int periodIndex = columnName.lastIndexOf('.");
        if (periodIndex != -1) {
            Exception e = new Exception();
            Log.e(TAG, "requesting column name with table name -- " + columnName, e);
            columnName = columnName.substring(periodIndex + 1);
        }

        Integer i = mColumnNameMap.get(columnName);
        if (i != null) {
            return i.intValue();
        } else {
            return -1;
        }
public java.lang.String[]getColumnNames()

        return mColumns;
public intgetCount()

        if (mCount == NO_COUNT) {
            fillWindow(0);
        }
        return mCount;
public SQLiteDatabasegetDatabase()
Get the database that this cursor is associated with.

return
the SQLiteDatabase that this cursor is associated with.

        return mQuery.getDatabase();
public booleanonMove(int oldPosition, int newPosition)

        // Make sure the row at newPosition is present in the window
        if (mWindow == null || newPosition < mWindow.getStartPosition() ||
                newPosition >= (mWindow.getStartPosition() + mWindow.getNumRows())) {
            fillWindow(newPosition);
        }

        return true;
public booleanrequery()

        if (isClosed()) {
            return false;
        }

        synchronized (this) {
            if (!mQuery.getDatabase().isOpen()) {
                return false;
            }

            if (mWindow != null) {
                mWindow.clear();
            }
            mPos = -1;
            mCount = NO_COUNT;

            mDriver.cursorRequeried(this);
        }

        try {
            return super.requery();
        } catch (IllegalStateException e) {
            // for backwards compatibility, just return false
            Log.w(TAG, "requery() failed " + e.getMessage(), e);
            return false;
        }
public voidsetSelectionArguments(java.lang.String[] selectionArgs)
Changes the selection arguments. The new values take effect after a call to requery().

        mDriver.setBindArguments(selectionArgs);
public voidsetWindow(android.database.CursorWindow window)

        super.setWindow(window);
        mCount = NO_COUNT;