Module org.tentackle.persistence
Package org.tentackle.persist

Class ResultSetCursor<T extends org.tentackle.pdo.PersistentDomainObject<T>>

  • Type Parameters:
    T - the retrieved type
    All Implemented Interfaces:
    java.lang.AutoCloseable, org.tentackle.misc.ScrollableResource<T>
    public class ResultSetCursor<T extends org.tentackle.pdo.PersistentDomainObject<T>>
extends java.lang.Object
implements org.tentackle.misc.ScrollableResource<T>
    A cursor for a ResultSetWrapper.
    Author:
    harald

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ResultSetCursor.FetchList<T>
      Adds a closed flag to saveObject a roundtrip in remote sessions.

    • Constructor Summary

      Constructors 
      Constructor Description
      ResultSetCursor​(org.tentackle.pdo.DomainContext context, RemoteResultSetCursor<T> remoteCursor)
      Creates a cursor for a remote session.
      Constructor for pdo objects.
      ResultSetCursor​(T pdo, org.tentackle.dbms.ResultSetWrapper rs)
      Creates a cursor for a local session.
      ResultSetCursor​(T pdo, org.tentackle.dbms.ResultSetWrapper rs, JoinedSelect<T> js)
      Creates a cursor for a local session.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void afterLast()
      Positions the cursor after the last row.
      Works even for empty cursoresources.rs.
      protected void assertNoJoins()
      Asserts that there are no joins in the query.
      protected void assertSessionIsLocal()
      Asserts that session is local.
      protected void assertSessionIsRemote()
      Asserts that session is remote.
      void beforeFirst()
      Positions the cursor before the first row.
      Works even for empty cursoresources.rs.
      void close()
      Closes the cursor.
      The cursor is opened in its constructor.
      protected void configureRemoteObject​(T pdo)
      Configures the remotely retrieved PDO.
      ResultSetCursor.FetchList<T> fetch()
      Fetches the next objects up to the fetchsize.
      This method is provided to minimize the number of roundtrips especially for remote cursoresources.rs.
      boolean first()
      Rewinds the cursor to the first row.
      T get()
      Gets the data object of the current row.
      org.tentackle.pdo.DomainContext getDomainContext()
      Gets the domain context.
      int getFetchDirection()
      Gets the fetch direction.
      int getFetchSize()
      Gets the fetchsize.
      JoinedSelect<T> getJoinedSelect()
      Gets the join configuration.
      RemoteResultSetCursor<T> getRemoteCursor()
      Gets the remote cursor.
      org.tentackle.dbms.ResultSetWrapper getResultSet()
      Gets the result set.
      int getRow()
      Gets the current row.
      Row numbers start at 1.
      org.tentackle.session.Session getSession()
      Gets the session.
      boolean isAfterLast()
      Checks whether the cursor is after the last row.
      boolean isBeforeFirst()
      Checks whether the cursor is before the first row.
      boolean isClosed()
      Returns whether the cursor is closed.
      boolean last()
      Positions the cursor on the last row.
      boolean next()
      Moves the cursor to the next row.
      If there are no more rows the current row remains unchanged.
      boolean previous()
      Moves the cursor to the previous row.
      If we are already at the beginning, the cursor remains unchanged.
      boolean scroll​(int rows)
      Moves the cursor a given number of rows.
      void setFetchDirection​(int direction)
      Sets the fetch direction.
      void setFetchSize​(int rows)
      Sets the fetchsize.
      This is the number of rows the cursor will fetch from the server in one batch.
      boolean setRow​(int row)
      Sets the cursor to a given row.
      Row numbers start at 1.
      java.util.List<T> toList()
      Returns the objects of this cursor as a list.
      protected void toList​(java.util.List<T> list)
      Adds the rest of the cursor to a list.
      java.util.List<T> toListAndClose()
      Returns the objects of this cursor as a list and closes this cursor.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • ResultSetCursor

        public ResultSetCursor​(T pdo,
                       org.tentackle.dbms.ResultSetWrapper rs,
                       JoinedSelect<T> js)
        Creates a cursor for a local session.
        Parameters:
        pdo - the PDO proxy
        rs - the result set
        js - the join configuration, null if no joins

      • ResultSetCursor

        public ResultSetCursor​(T pdo,
                       org.tentackle.dbms.ResultSetWrapper rs)
        Creates a cursor for a local session.
        Parameters:
        pdo - the PDO proxy
        rs - the result set

      • ResultSetCursor

        public ResultSetCursor​(org.tentackle.pdo.DomainContext context,
                       RemoteResultSetCursor<T> remoteCursor)
        Creates a cursor for a remote session.
        Constructor for pdo objects.
        Parameters:
        context - the domain context
        remoteCursor - the remote cursor

    • Method Detail

      • getResultSet

        public org.tentackle.dbms.ResultSetWrapper getResultSet()
        Gets the result set.
        Returns:
        the result set

      • getJoinedSelect

        public JoinedSelect<T> getJoinedSelect()
        Gets the join configuration.
        Returns:
        the join configuration, null if no joins
        Throws:
        org.tentackle.session.PersistenceException - if session is remote

      • getRemoteCursor

        public RemoteResultSetCursor<T> getRemoteCursor()
        Gets the remote cursor.
        Returns:
        the remote cursor
        Throws:
        org.tentackle.session.PersistenceException - if session is local

      • getSession

        public org.tentackle.session.Session getSession()
        Gets the session.
        Returns:
        the session

      • getDomainContext

        public org.tentackle.pdo.DomainContext getDomainContext()
        Gets the domain context.
        Returns:
        the context

      • close

        public void close()
        Closes the cursor.
        The cursor is opened in its constructor. Closing an already closed cursor is allowed.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>

      • isClosed

        public boolean isClosed()
        Returns whether the cursor is closed.
        Specified by:
        isClosed in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if closed

      • getRow

        public int getRow()
        Gets the current row.
        Row numbers start at 1.
        Specified by:
        getRow in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the current row, 0 if before first row

      • setRow

        public boolean setRow​(int row)
        Sets the cursor to a given row.
        Row numbers start at 1.
        Specified by:
        setRow in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Parameters:
        row - the row number (must be ≥ 0)
        Returns:
        true if done, false if no such row and the cursor is now before the first row or after the last row

      • first

        public boolean first()
        Rewinds the cursor to the first row.
        Specified by:
        first in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if rewound, false if cursor is empty

      • last

        public boolean last()
        Positions the cursor on the last row.
        Specified by:
        last in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if positioned, false if cursor is empty

      • next

        public boolean next()
        Moves the cursor to the next row.
        If there are no more rows the current row remains unchanged.
        Specified by:
        next in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if moved, false if no more rows

      • previous

        public boolean previous()
        Moves the cursor to the previous row.
        If we are already at the beginning, the cursor remains unchanged.
        Specified by:
        previous in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if advanced, false if already at the beginning

      • scroll

        public boolean scroll​(int rows)
        Moves the cursor a given number of rows.
        Specified by:
        scroll in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Parameters:
        rows - the number of rows to move, negative to move backwards
        Returns:
        true if moved, false if no such row and the cursor is now positioned before the first row or after the last row

      • beforeFirst

        public void beforeFirst()
        Positions the cursor before the first row.
        Works even for empty cursoresources.rs.
        Specified by:
        beforeFirst in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>

      • afterLast

        public void afterLast()
        Positions the cursor after the last row.
        Works even for empty cursoresources.rs.
        Specified by:
        afterLast in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>

      • isBeforeFirst

        public boolean isBeforeFirst()
        Checks whether the cursor is before the first row.
        Specified by:
        isBeforeFirst in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if before first

      • isAfterLast

        public boolean isAfterLast()
        Checks whether the cursor is after the last row.
        Specified by:
        isAfterLast in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        true if after last

      • get

        public T get()
        Gets the data object of the current row.
        Specified by:
        get in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the object, null if invalid row or no such object

      • toList

        public java.util.List<T> toList()
        Returns the objects of this cursor as a list.
        Specified by:
        toList in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the list

      • toListAndClose

        public java.util.List<T> toListAndClose()
        Returns the objects of this cursor as a list and closes this cursor.
        Specified by:
        toListAndClose in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the list

      • setFetchSize

        public void setFetchSize​(int rows)
        Sets the fetchsize.
        This is the number of rows the cursor will fetch from the server in one batch. A fetchsize of 0 means server default.
        Specified by:
        setFetchSize in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Parameters:
        rows - the fetchsize

      • getFetchSize

        public int getFetchSize()
        Gets the fetchsize.
        Specified by:
        getFetchSize in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the fetchsize

      • setFetchDirection

        public void setFetchDirection​(int direction)
        Sets the fetch direction.
        Parameters:
        direction - the direction, see ResultSet.setFetchDirection(int).

      • getFetchDirection

        public int getFetchDirection()
        Gets the fetch direction.
        Returns:
        the direction

      • fetch

        public ResultSetCursor.FetchList<T> fetch()
        Fetches the next objects up to the fetchsize.
        This method is provided to minimize the number of roundtrips especially for remote cursoresources.rs. The cursor is closed at the end of the cursor.
        Specified by:
        fetch in interface org.tentackle.misc.ScrollableResource<T extends org.tentackle.pdo.PersistentDomainObject<T>>
        Returns:
        the list of objects, null if no more objects found

      • toList

        protected void toList​(java.util.List<T> list)
        Adds the rest of the cursor to a list.
        Parameters:
        list - the list

      • configureRemoteObject

        protected void configureRemoteObject​(T pdo)
        Configures the remotely retrieved PDO.
        Parameters:
        pdo - the PDO

      • assertSessionIsRemote

        protected void assertSessionIsRemote()
        Asserts that session is remote.

      • assertSessionIsLocal

        protected void assertSessionIsLocal()
        Asserts that session is local.

      • assertNoJoins

        protected void assertNoJoins()
        Asserts that there are no joins in the query.