Java IO.pdf - Nguyen Dang Binh

System.out.println(theLine);
}
}
catch (IOException e) {System.err.println(e);}
}
}
Java I/O
A sample run follows. Notice the deprecation warning when this code is compiled.
DataInputStream's readLine() method is one of the most common sources of deprecation
warnings in Java 1.1.
% javac Echo.java
Note: Echo.java uses a deprecated API. Recompile with "-deprecation" for
details.
1 warning
% java Echo
This is a test
This is a test
This is another test
This is another test
Hello
Hello
Goodbye Now
Goodbye Now
.
%
Although we won't officially take up readers until Chapter 15, it's not very hard to rewrite this
program so that it doesn't generate deprecation warnings. All you need to do is replace
DataInputStream with BufferedReader chained to an InputStreamReader. Example 7.7
demonstrates.
Example 7.7. The ReaderEcho Program
import java.io.*;
public class ReaderEcho {
}
public static void main(String[] args) {
}
try {
BufferedReader din = new BufferedReader
(new InputStreamReader(System.in), 1);
while (true) {
String theLine = din.readLine();
if (theLine == null) break; // end of stream
if (theLine.equals(".")) break; // . on line by itself
System.out.println(theLine);
}
}
catch (IOException e) {System.err.println(e);}
This only works (and is only needed) for readLine(). BufferedReader does not have
equivalents for the rest of the DataInputStream methods like readFully(), but more details
will wait until Chapter 15.
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