com.ibm.as400.access
Class IFSFileReader

java.lang.Object
  |
  +--java.io.Reader
        |
        +--com.ibm.as400.access.IFSFileReader

public class IFSFileReader

extends Reader

Convenience class for reading character files in the integrated file system. The behavior of this class is comparable to java.io.FileReader. IFSFileReader is meant for reading streams of characters. For reading streams of raw bytes, consider using a IFSFileInputStream.
The following example illustrates the use of IFSFileReader:

import java.io.BufferedReader;
// Work with /File1 on the system eniac.
AS400 system = new AS400("eniac");
IFSFile file = new IFSFile(system, "/File1");
BufferedReader reader = new BufferedReader(new IFSFileReader(file));
// Read the first line of the file, converting characters.
String line1 = reader.readLine();
// Display the String that was read.
System.out.println(line1);
// Close the reader.
reader.close();

SHARE_ALL

public static final int SHARE_ALL

Share option that allows read and write access by other users.

See Also:

Constant Field Values

SHARE_NONE

public static final int SHARE_NONE

Share option that does not allow read or write access by other users.

See Also:

Constant Field Values

SHARE_READERS

public static final int SHARE_READERS

Share option that allows only read access by other users.

See Also:

Constant Field Values

SHARE_WRITERS

public static final int SHARE_WRITERS

Share option that allows only write access by other users.

See Also:

Constant Field Values

IFSFileReader

public IFSFileReader(IFSFile file)
              throws AS400SecurityException,
                     IOException

Constructs an IFSFileReader object. Other readers and writers are allowed to access the file. The file is opened if it exists; otherwise an exception is thrown. The file's CCSID is obtained by referencing the file's "coded character set ID" tag on the server. Other readers and writers are allowed to access the file.

Parameters:

file - The file to be opened for reading.

Throws:AS400SecurityException - If a security or authority error occurs.

IOException - If an error occurs while communicating with the server.

IFSFileReader

public IFSFileReader(IFSFile file,
                     int ccsid)
              throws AS400SecurityException,
                     IOException

Constructs an IFSFileReader object. The file is opened if it exists; otherwise an exception is thrown. Other readers and writers are allowed to access the file.

Parameters:

file - The file to be opened for reading.

ccsid - The CCSID that the file data is currently in.

Throws:

AS400SecurityException - If a security or authority error occurs.

IOException - If an error occurs while communicating with the server.

IFSFileReader

public IFSFileReader(IFSFile file,
                     int ccsid,
                     int shareOption)
              throws AS400SecurityException,
                     IOException

Constructs an IFSFileReader object. The file is opened if it exists; otherwise an exception is thrown.

Parameters:

file - The file to be opened for reading.

ccsid - The CCSID that the file data is currently in.

shareOption - Indicates how users can access the file.

• SHARE_ALL Share access with readers and writers
• SHARE_NONE Share access with none
• SHARE_READERS Share access with readers
• SHARE_WRITERS Share access with writers

Throws:

AS400SecurityException - If a security or authority error occurs.

IOException - If an error occurs while communicating with the server.

IFSFileReader

public IFSFileReader(IFSFileDescriptor fd)
              throws AS400SecurityException,
                     IOException

Constructs an IFSFileReader object. The file is opened if it exists; otherwise an exception is thrown.

Parameters:

fd - The file descriptor to be opened for reading.

close

public void close()
           throws IOException

Closes the stream. Once a stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously-closed stream, however, has no effect.

Specified by:

close in class Reader

Throws:

IOException - If an error occurs while communicating with the server.

getCCSID

public int getCCSID()

Returns the CCSID used by this IFSFileReader.

Returns:

The CCSID, or -1 if the CCSID is not known.

getEncoding

public String getEncoding()

Returns the encoding used by this IFSFileReader.

Returns:

The encoding, or null if the encoding is not known.

markSupported

public boolean markSupported()

IFSFileReader does not support the mark() operation.

Overrides:

markSupported in class Reader

Returns:

false.

read

public int read()
         throws IOException

Reads a single character.

Overrides:

read in class Reader

Returns:

The character read, or -1 if the end of the stream has been reached.

Throws:

IOException - If an error occurs while communicating with the server.

read

public int read(char[] cbuf)
         throws IOException

Reads characters into an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.

Overrides:

read in class Reader

Parameters:

cbuf - Destination buffer.

Returns:

The number of characters read, or -1 if the end of the stream has been reached.

Throws:

IOException - If an error occurs while communicating with the server.

read

public int read(char[] cbuf,
                int off,
                int len)
         throws IOException

Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.

Specified by:

read in class Reader

Parameters:

cbuf - Destination buffer.

off - Offset at which to start storing characters.

len - Maximum number of characters to read.

Returns:

The number of characters read, or -1 if the end of the stream has been reached.

Throws:

IOException - If an error occurs while communicating with the server.

ready

public boolean ready()
              throws IOException

Tells whether this stream is ready to be read.

Overrides:

ready in class Reader

Returns:

true if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

Throws:

IOException - If an error occurs while communicating with the server.

reset

public void reset()
           throws IOException

Resets the stream. After this call, the stream will read from the beginning.

Overrides:

reset in class Reader

Throws:

IOException - If an error occurs while communicating with the server.

skip

public long skip(long charsToSkip)
          throws IOException

Skip characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.

Overrides:

skip in class Reader

Parameters:

charsToSkip - The number of characters to skip.

Returns:

The number of characters actually skipped.

Throws:

IOException - If an error occurs while communicating with the server.

lockBytes

public IFSKey lockBytes(int length)
                 throws IOException

Places a lock on the file at the current position for the specified number of bytes.

Parameters:

length - The number of bytes to lock.

Returns:

The key for undoing this lock.

Throws:

IOException - If an error occurs while communicating with the server.

See Also:

unlockBytes(com.ibm.as400.access.IFSKey)

unlockBytes

public void unlockBytes(IFSKey key)
                 throws IOException

Undoes a lock on the file.

Parameters:

key - The key for the lock.

Throws:

IOException - If an error occurs while communicating with the server.

See Also:

lockBytes(int)