Package org.postgresql.largeobject

Class LargeObjectManager

  • public class LargeObjectManager
extends java.lang.Object
    This class implements the large object interface to org.postgresql.

    It provides methods that allow client code to create, open and delete large objects from the database. When opening an object, an instance of org.postgresql.largeobject.LargeObject is returned, and its methods then allow access to the object.

    This class can only be created by BaseConnection

    To get access to this class, use the following segment of code:

     import org.postgresql.largeobject.*;

 Connection  conn;
 LargeObjectManager lobj;

 ... code that opens a connection ...

 lobj = ((org.postgresql.PGConnection)myconn).getLargeObjectAPI();

    Normally, client code would use the getAsciiStream, getBinaryStream, or getUnicodeStream methods in ResultSet, or setAsciiStream, setBinaryStream, or setUnicodeStream methods in PreparedStatement to access Large Objects.

    However, sometimes lower level access to Large Objects are required, that are not supported by the JDBC specification.

    Refer to org.postgresql.largeobject.LargeObject on how to manipulate the contents of a Large Object.

    See Also:
    ResultSet.getAsciiStream(int), ResultSet.getBinaryStream(int), ResultSet.getUnicodeStream(int), PreparedStatement.setAsciiStream(int, java.io.InputStream, int), PreparedStatement.setBinaryStream(int, java.io.InputStream, int), PreparedStatement.setUnicodeStream(int, java.io.InputStream, int)

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int READ
      This mode indicates we want to read an object.
      static int READWRITE
      This mode is the default.
      static int WRITE
      This mode indicates we want to write to an object.

    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      int create()
      Deprecated.
      As of 8.3, replaced by createLO()
      int create​(int mode)
      Deprecated.
      As of 8.3, replaced by createLO(int)
      long createLO()
      This creates a large object, returning its OID.
      long createLO​(int mode)
      This creates a large object, returning its OID.
      void delete​(int oid)
      Deprecated.
      As of 8.3, replaced by delete(long)
      void delete​(long oid)
      This deletes a large object.
      LargeObject open​(int oid)
      Deprecated.
      As of 8.3, replaced by open(long)
      LargeObject open​(int oid, boolean commitOnClose)
      This opens an existing large object, same as previous method, but commits the transaction on close if asked.
      LargeObject open​(int oid, int mode)
      Deprecated.
      As of 8.3, replaced by open(long, int)
      LargeObject open​(int oid, int mode, boolean commitOnClose)
      This opens an existing large object, same as previous method, but commits the transaction on close if asked.
      LargeObject open​(long oid)
      This opens an existing large object, based on its OID.
      LargeObject open​(long oid, boolean commitOnClose)
      This opens an existing large object, same as previous method, but commits the transaction on close if asked.
      LargeObject open​(long oid, int mode)
      This opens an existing large object, based on its OID.
      LargeObject open​(long oid, int mode, boolean commitOnClose)
      This opens an existing large object, based on its OID.
      void unlink​(int oid)
      Deprecated.
      As of 8.3, replaced by unlink(long)
      void unlink​(long oid)
      This deletes a large object.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • WRITE

        public static final int WRITE
        This mode indicates we want to write to an object.
        See Also:
        Constant Field Values

      • READ

        public static final int READ
        This mode indicates we want to read an object.
        See Also:
        Constant Field Values

      • READWRITE

        public static final int READWRITE
        This mode is the default. It indicates we want read and write access to a large object.
        See Also:
        Constant Field Values

    • Constructor Detail

      • LargeObjectManager

        public LargeObjectManager​(BaseConnection conn)
                   throws java.sql.SQLException
        Constructs the LargeObject API.

        Important Notice
        This method should only be called by BaseConnection

        There should only be one LargeObjectManager per Connection. The BaseConnection class keeps track of the various extension API's and it's advised you use those to gain access, and not going direct.

        Parameters:
        conn - connection
        Throws:
        java.sql.SQLException - if something wrong happens

    • Method Detail

      • open

        @Deprecated
public LargeObject open​(int oid)
                 throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by open(long)
        This opens an existing large object, based on its OID. This method assumes that READ and WRITE access is required (the default).
        Parameters:
        oid - of large object
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(int oid,
                        boolean commitOnClose)
                 throws java.sql.SQLException
        This opens an existing large object, same as previous method, but commits the transaction on close if asked. This is useful when the LOB is returned to a caller which won't take care of transactions by itself.
        Parameters:
        oid - of large object
        commitOnClose - commit the transaction when this LOB will be closed
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(long oid)
                 throws java.sql.SQLException
        This opens an existing large object, based on its OID. This method assumes that READ and WRITE access is required (the default).
        Parameters:
        oid - of large object
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(long oid,
                        boolean commitOnClose)
                 throws java.sql.SQLException
        This opens an existing large object, same as previous method, but commits the transaction on close if asked.
        Parameters:
        oid - of large object
        commitOnClose - commit the transaction when this LOB will be closed
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        @Deprecated
public LargeObject open​(int oid,
                        int mode)
                 throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by open(long, int)
        This opens an existing large object, based on its OID.
        Parameters:
        oid - of large object
        mode - mode of open
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(int oid,
                        int mode,
                        boolean commitOnClose)
                 throws java.sql.SQLException
        This opens an existing large object, same as previous method, but commits the transaction on close if asked.
        Parameters:
        oid - of large object
        mode - mode of open
        commitOnClose - commit the transaction when this LOB will be closed
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(long oid,
                        int mode)
                 throws java.sql.SQLException
        This opens an existing large object, based on its OID.
        Parameters:
        oid - of large object
        mode - mode of open
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • open

        public LargeObject open​(long oid,
                        int mode,
                        boolean commitOnClose)
                 throws java.sql.SQLException
        This opens an existing large object, based on its OID.
        Parameters:
        oid - of large object
        mode - mode of open
        commitOnClose - commit the transaction when this LOB will be closed
        Returns:
        LargeObject instance providing access to the object
        Throws:
        java.sql.SQLException - on error

      • create

        @Deprecated
public int create()
           throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by createLO()
        This creates a large object, returning its OID.

        It defaults to READWRITE for the new object's attributes.

        Returns:
        oid of new object
        Throws:
        java.sql.SQLException - on error

      • createLO

        public long createLO()
              throws java.sql.SQLException
        This creates a large object, returning its OID.

        It defaults to READWRITE for the new object's attributes.

        Returns:
        oid of new object
        Throws:
        java.sql.SQLException - if something wrong happens

      • createLO

        public long createLO​(int mode)
              throws java.sql.SQLException
        This creates a large object, returning its OID.
        Parameters:
        mode - a bitmask describing different attributes of the new object
        Returns:
        oid of new object
        Throws:
        java.sql.SQLException - on error

      • create

        @Deprecated
public int create​(int mode)
           throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by createLO(int)
        This creates a large object, returning its OID.
        Parameters:
        mode - a bitmask describing different attributes of the new object
        Returns:
        oid of new object
        Throws:
        java.sql.SQLException - on error

      • delete

        public void delete​(long oid)
            throws java.sql.SQLException
        This deletes a large object.
        Parameters:
        oid - describing object to delete
        Throws:
        java.sql.SQLException - on error

      • unlink

        @Deprecated
public void unlink​(int oid)
            throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by unlink(long)
        This deletes a large object.

        It is identical to the delete method, and is supplied as the C API uses unlink.

        Parameters:
        oid - describing object to delete
        Throws:
        java.sql.SQLException - on error

      • unlink

        public void unlink​(long oid)
            throws java.sql.SQLException
        This deletes a large object.

        It is identical to the delete method, and is supplied as the C API uses unlink.

        Parameters:
        oid - describing object to delete
        Throws:
        java.sql.SQLException - on error

      • delete

        @Deprecated
public void delete​(int oid)
            throws java.sql.SQLException
        Deprecated.
        As of 8.3, replaced by delete(long)
        This deletes a large object.
        Parameters:
        oid - describing object to delete
        Throws:
        java.sql.SQLException - on error