This class is a character input stream that keeps track of the number of lines of text that have been read from it. It supports the usual Reader methods and also the readLine( ) method introduced by its superclass. In addition to these methods, you can call getLineNumber( ) to query the number of lines set so far. You can also call setLineNumber( ) to set the line number for the current line. Subsequent lines are numbered sequentially from this specified starting point. This class is a character-stream analog to LineNumberInputStream, which has been deprecated as of Java 1.1.

Figure 9-32. java.io.LineNumberReader

public class LineNumberReader extends BufferedReader {
// Public Constructors
     public LineNumberReader(Reader in);  
     public LineNumberReader(Reader in, int sz);  
// Public Instance Methods
     public int getLineNumber( );  
     public void setLineNumber(int lineNumber);  
// Public Methods Overriding BufferedReader
     public void mark(int readAheadLimit) throws IOException;  
     public int read( ) throws IOException;  
     public int read(char[ ] cbuf, int off, int len) throws IOException;  
     public String readLine( ) throws IOException;  
     public void reset( ) throws IOException;  
     public long skip(long n) throws IOException;  
}