Overview  Package   Class  Use  Deprecated  Index
Home >> All >> postgresql >> [ largeobject overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

postgresql.largeobject
Class LargeObject  

java.lang.Object
  postgresql.largeobject.LargeObject

---

public class LargeObject

extends java.lang.Object

This class implements the large object interface to postgresql.

It provides the basic methods required to run the interface, plus a pair of methods that provide InputStream and OutputStream classes for this object.

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 postgresql.largeobject.LargeObjectManager on how to gain access to a Large Object, or how to create one.

---

Field Summary
private  int	fd
private  postgresql.fastpath.Fastpath	fp
private  int	oid
static int	SEEK_CUR           Indicates a seek from the current position
static int	SEEK_END           Indicates a seek from the end of a file
static int	SEEK_SET           Indicates a seek from the begining of a file

 

Constructor Summary
protected	LargeObject(postgresql.fastpath.Fastpath fp, int oid, int mode)           This opens a large object.

 

Method Summary
void	close()           This method closes the object.
java.io.InputStream	getInputStream()           Returns an InputStream from this object.
int	getOID()
java.io.OutputStream	getOutputStream()           Returns an OutputStream to this object
void	read(byte[] buf, int off, int len)           Reads some data from the object into an existing array
byte[]	read(int len)           Reads some data from the object, and return as a byte[] array
void	seek(int pos)           Sets the current position within the object.
void	seek(int pos, int ref)           Sets the current position within the object.
int	size()           This method is inefficient, as the only way to find out the size of the object is to seek to the end, record the current position, then return to the original position.
int	tell()
void	write(byte[] buf)           Writes an array to the object
void	write(byte[] buf, int off, int len)           Writes some data from an array to the object

 

Methods inherited from class java.lang.Object

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

 

Field Detail

SEEK_SET

public static final int SEEK_SET

Indicates a seek from the begining of a file

See Also:

Constant Field Values

---

SEEK_CUR

public static final int SEEK_CUR

Indicates a seek from the current position

See Also:

Constant Field Values

---

SEEK_END

public static final int SEEK_END

Indicates a seek from the end of a file

See Also:

Constant Field Values

---

fp

private postgresql.fastpath.Fastpath fp

---

oid

private int oid

---

fd

private int fd

Constructor Detail

LargeObject

protected LargeObject(postgresql.fastpath.Fastpath fp,
                      int oid,
                      int mode)
               throws java.sql.SQLException

This opens a large object.

If the object does not exist, then an SQLException is thrown.

Method Detail

getOID

public int getOID()

---

close

public void close()
           throws java.sql.SQLException

This method closes the object. You must not call methods in this object after this is called.

---

read

public byte[] read(int len)
            throws java.sql.SQLException

Reads some data from the object, and return as a byte[] array

---

read

public void read(byte[] buf,
                 int off,
                 int len)
          throws java.sql.SQLException

Reads some data from the object into an existing array

---

write

public void write(byte[] buf)
           throws java.sql.SQLException

Writes an array to the object

---

write

public void write(byte[] buf,
                  int off,
                  int len)
           throws java.sql.SQLException

Writes some data from an array to the object

---

seek

public void seek(int pos,
                 int ref)
          throws java.sql.SQLException

Sets the current position within the object.

This is similar to the fseek() call in the standard C library. It allows you to have random access to the large object.

---

seek

public void seek(int pos)
          throws java.sql.SQLException

Sets the current position within the object.

This is similar to the fseek() call in the standard C library. It allows you to have random access to the large object.

---

tell

public int tell()
         throws java.sql.SQLException

---

size

public int size()
         throws java.sql.SQLException

This method is inefficient, as the only way to find out the size of the object is to seek to the end, record the current position, then return to the original position.

A better method will be found in the future.

---

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.sql.SQLException

Returns an InputStream from this object.

This InputStream can then be used in any method that requires an InputStream.

---

getOutputStream

public java.io.OutputStream getOutputStream()
                                     throws java.sql.SQLException

Returns an OutputStream to this object

This OutputStream can then be used in any method that requires an OutputStream.

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> postgresql >> [ largeobject overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---