PGCopyInputStream (PostgreSQL JDBC Driver

java.lang.Object
- java.io.InputStream
- - org.postgresql.copy.PGCopyInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, CopyOperation, CopyOut
```
public class PGCopyInputStream
extends InputStream
implements CopyOut
```
InputStream for reading from a PostgreSQL COPY TO STDOUT operation.

Constructor Summary

Constructors
Constructor and Description
`PGCopyInputStream(CopyOut op)` Use given CopyOut operation for reading.
`PGCopyInputStream(PGConnection connection, String sql)` Uses given connection for specified COPY TO STDOUT operation.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
`void`	`cancelCopy()` Cancels this copy operation, discarding any exchanged data.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`int`	`getFieldCount()`
`int`	`getFieldFormat(int field)`
`int`	`getFormat()`
`long`	`getHandledRowCount()` After succesful end of copy, returns the number of database records handled in that operation.
`boolean`	`isActive()`
`int`	`read()` Reads the next byte of data from the input stream.
`int`	`read(byte[] buf)` Reads some number of bytes from the input stream and stores them into the buffer array `b`.
`int`	`read(byte[] buf, int off, int siz)` Reads up to `len` bytes of data from the input stream into an array of bytes.
`byte[]`	`readFromCopy()` Blocks wait for a row of data to be received from server on an active copy operation.
`byte[]`	`readFromCopy(boolean block)` Wait for a row of data to be received from server on an active copy operation.

Methods inherited from class java.io.InputStream
mark, markSupported, reset, skip

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - PGCopyInputStream
```
public PGCopyInputStream(PGConnection connection,
                         String sql)
                  throws SQLException
```
    Uses given connection for specified COPY TO STDOUT operation.
    
    Parameters:
    
    connection - database connection to use for copying (protocol version 3 required)
    
    sql - COPY TO STDOUT statement
    
    Throws:
    
    SQLException - if initializing the operation fails
  - PGCopyInputStream
```
public PGCopyInputStream(CopyOut op)
```
    Use given CopyOut operation for reading.
    
    Parameters:
    
    op - COPY TO STDOUT operation
- Method Detail
  - available
```
public int available()
              throws IOException
```
    Description copied from class: java.io.InputStream
    
    Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.
    Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.
    A subclass' implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the InputStream.close() method.
    The available method for class InputStream always returns 0.
    This method should be overridden by subclasses.
    
    Overrides:
    
    available in class InputStream
    
    Returns:
    
    an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.
    
    Throws:
    
    IOException - if an I/O error occurs.
  - read
```
public int read()
         throws IOException
```
    Description copied from class: java.io.InputStream
    
    Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
    A subclass must provide an implementation of this method.
    
    Specified by:
    
    read in class InputStream
    
    Returns:
    
    the next byte of data, or -1 if the end of the stream is reached.
    
    Throws:
    
    IOException - if an I/O error occurs.
  - read
```
public int read(byte[] buf)
         throws IOException
```
    Description copied from class: java.io.InputStream
    Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.
    If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and stored into b.
    The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.
    The read(b) method for class InputStream has the same effect as:
```
 read(b, 0, b.length) 
```
    Overrides:
    
    read in class InputStream
    
    Parameters:
    
    buf - the buffer into which the data is read.
    
    Returns:
    
    the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
    
    Throws:
    
    IOException - If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.
    
    See Also:
    
    InputStream.read(byte[], int, int)
  - read
```
public int read(byte[] buf,
                int off,
                int siz)
         throws IOException
```
    Description copied from class: java.io.InputStream
    
    Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.
    This method blocks until input data is available, end of file is detected, or an exception is thrown.
    If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.
    The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.
    In every case, elements b[0] through b[off] and elements b[off+len] through b[b.length-1] are unaffected.
    The read(b, off, len) method for class InputStream simply calls the method read() repeatedly. If the first such call results in an IOException, that exception is returned from the call to the read(b, off, len) method. If any subsequent call to read() results in a IOException, the exception is caught and treated as if it were end of file; the bytes read up to that point are stored into b and the number of bytes read before the exception occurred is returned. The default implementation of this method blocks until the requested amount of input data len has been read, end of file is detected, or an exception is thrown. Subclasses are encouraged to provide a more efficient implementation of this method.
    
    Overrides:
    
    read in class InputStream
    
    Parameters:
    
    buf - the buffer into which the data is read.
    
    off - the start offset in array b at which the data is written.
    
    siz - the maximum number of bytes to read.
    
    Returns:
    
    the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
    
    Throws:
    
    IOException - If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
    
    See Also:
    
    InputStream.read()
  - readFromCopy
```
public byte[] readFromCopy()
                    throws SQLException
```
    Description copied from interface: CopyOut
    
    Blocks wait for a row of data to be received from server on an active copy operation.
    
    Specified by:
    
    readFromCopy in interface CopyOut
    
    Returns:
    
    byte array received from server, null if server complete copy operation
    
    Throws:
    
    SQLException - if something goes wrong for example socket timeout
  - readFromCopy
```
public byte[] readFromCopy(boolean block)
                    throws SQLException
```
    Description copied from interface: CopyOut
    
    Wait for a row of data to be received from server on an active copy operation.
    
    Specified by:
    
    readFromCopy in interface CopyOut
    
    Parameters:
    
    block - true if need wait data from server otherwise false and will read pending message from server
    
    Returns:
    
    byte array received from server, if pending message from server absent and use no blocking mode return null
    
    Throws:
    
    SQLException - if something goes wrong for example socket timeout
  - close
```
public void close()
           throws IOException
```
    Description copied from class: java.io.InputStream
    
    Closes this input stream and releases any system resources associated with the stream.
    The close method of InputStream does nothing.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class InputStream
    
    Throws:
    
    IOException - if an I/O error occurs.
  - cancelCopy
```
public void cancelCopy()
                throws SQLException
```
    Description copied from interface: CopyOperation
    
    Cancels this copy operation, discarding any exchanged data.
    
    Specified by:
    
    cancelCopy in interface CopyOperation
    
    Throws:
    
    SQLException - if cancelling fails
  - getFormat
```
public int getFormat()
```
    Specified by:
    
    getFormat in interface CopyOperation
    
    Returns:
    
    overall format of each row: 0 = textual, 1 = binary
  - getFieldFormat
```
public int getFieldFormat(int field)
```
    Specified by:
    
    getFieldFormat in interface CopyOperation
    
    Parameters:
    
    field - number of field (0..fieldCount()-1)
    
    Returns:
    
    format of requested field: 0 = textual, 1 = binary
  - getFieldCount
```
public int getFieldCount()
```
    Specified by:
    
    getFieldCount in interface CopyOperation
    
    Returns:
    
    number of fields in each row for this operation
  - isActive
```
public boolean isActive()
```
    Specified by:
    
    isActive in interface CopyOperation
    
    Returns:
    
    is connection reserved for this Copy operation?
  - getHandledRowCount
```
public long getHandledRowCount()
```
    Description copied from interface: CopyOperation
    
    After succesful end of copy, returns the number of database records handled in that operation. Only implemented in PostgreSQL server version 8.2 and up. Otherwise, returns -1.
    
    Specified by:
    
    getHandledRowCount in interface CopyOperation
    
    Returns:
    
    number of handled rows or -1

Class PGCopyInputStream

Constructor Summary

Method Summary

Methods inherited from class java.io.InputStream

Methods inherited from class java.lang.Object

Constructor Detail

PGCopyInputStream

PGCopyInputStream

Method Detail

available

read

read

read

readFromCopy

readFromCopy

close

cancelCopy

getFormat

getFieldFormat

getFieldCount

isActive

getHandledRowCount