com.nt.udc.io

Interface IDataSource

All Known Implementing Classes:

CDataSourceFileMgr, CDataSourceSingleFile, CDataSourceSuperTail

public interface IDataSource

This interface is to be implemented by character stream data sources.

Since:

JDK1.1.7

Field Summary

Fields

Modifier and Type	Field and Description
static char	EOF

Method Summary

Methods

Modifier and Type	Method and Description
boolean	end() This function is called to end reading.
java.lang.String	getSourceName()
boolean	hasMoreData()
boolean	initialize() This function is called to initialize the data source.
boolean	isHealthy()
char	nextChar()
int	read(char[] buf, int len) This function reads a given number of characters from the source.
boolean	setBookmark(int lineNo) This function is called to mark a certain position in the input stream.
boolean	start() This function is called to start reading.
boolean	terminate() This function is called to terminate the data source.

Field Detail

EOF

static final char EOF

See Also:

Constant Field Values

Method Detail

getSourceName

java.lang.String getSourceName()

Returns:

The name of the source.

hasMoreData

boolean hasMoreData()

Returns:

true if more input is available.

nextChar

char nextChar()
              throws java.lang.Exception

Returns:

The next character from the input. If no more characters are available, IDataSource.EOF is returned instead.

Throws:

java.lang.Exception

read

int read(char[] buf,
       int len)
         throws java.lang.Exception

This function reads a given number of characters from the source.

Returns:

The number of characters actually read.

Throws:

java.lang.Exception

initialize

boolean initialize()

This function is called to initialize the data source.

terminate

boolean terminate()

This function is called to terminate the data source.

start

boolean start()

This function is called to start reading. Classes implementing IDataSource may use it for initialization.

Returns:

true if successful, false otherwise

end

boolean end()

This function is called to end reading. Classes implementing IDataSource may use it for clean-up operations.

Returns:

true if successful, false otherwise

setBookmark

boolean setBookmark(int lineNo)

This function is called to mark a certain position in the input stream. This mark may be stored on a persistent medium in order to avoid re-reading the same data during the next reading session.

isHealthy

boolean isHealthy()

Returns:

true if the data source is OK, false otherwise.