java.io.BufferedReader class is a subclass of
java.io.Reader that you chain to another Reader class to
buffer characters. This allows more efficient
reading of characters and lines.
The BufferedReader is also notable for its readLine() method that allows you to read text a line at a time.
Each time you read from an unbuffered Reader, there's a matching read
from the underlying input stream. Therefore it's a good idea to wrap a BufferedReader around each
Reader whose read() operations
are expensive, such as a FileReader. For example,
BufferedReader br = new BufferedReader(new FileReader("37.html"));
public BufferedReader(Reader in, int sz)
public BufferedReader(Reader in)
readLine().
public String readLine() throws IOException
String that contains a line of text from a text file. \r, \n, and \r\n are assumed to be line breaks and are not included in the returned String. The following example reads a text file, line by line, and prints it to System.out:
// Implement the Unix cat utility in java
import java.io.*;
class cat {
public static void main (String args[]) {
String thisLine;
//Loop across the arguments
for (int i=0; i < args.length; i++) {
//Open the file for reading
try {
BufferedReader br = new BufferedReader(new FileReader(args[i]));
while ((thisLine = br.readLine()) != null) { // while loop begins here
System.out.println(thisLine);
} // end while
} // end try
catch (IOException e) {
System.err.println("Error: " + e);
}
} // end for
} // end main
}BufferedReaders do support marking and resetting, at least
up to the
length of the buffer.
public boolean markSupported()
public void mark(int readAheadLimit) throws IOException
public void reset() throws IOException
BufferedReader overrides several methods from the superclass Reader;
but how you use them does not change at all:
public int read() throws IOException
public int read(char c[], int off, int length) throws IOException
public long skip(long n) throws IOException
public boolean ready() throws IOException
public void close() throws IOException