Reading files a la for-each loop.
January 27th, 2009
This post will show you how to use the for-each loop for reading files. This approach tried to replace the following approach
try {
BufferedReader in = new BufferedReader(new FileReader("infilename"));
String str;
while ((str = in.readLine()) != null) {
process(str);
}
in.close();
} catch (IOException e) {
}
with this one:
final IterableFileReader e = new IterableFileReader(new File("SomeFile.WithSomeExtension"));
for(String eachLine: e){
process(eachLine);
}
The source code of my solution is illustrated herein:
public class IterableFileReader implements Iterable<String>{
private final BufferedReader reader;
public IterableFileReader(InputStream is, Charset encoding) throws IOException {
reader = new BufferedReader(new InputStreamReader(is, encoding.toString()));
}
public IterableFileReader(File file) throws IOException {
this(new FileInputStream(file), Charset.UTF_8);
}
public Iterator<String> iterator() {
return new Iterator<String>(){
private String line;
public boolean hasNext() {
try {
line = reader.readLine();
} catch (IOException e) {
throw new IllegalStateException(e);
}
return line != null;
}
public String next() {
return line;
}
public void remove() {
throw new UnsupportedOperationException("remove is not supported. sorry dude!");
}
};
}
}
I hope you will find this approach useful. Ok, time is up. I gotta go, my daughter is crying. Till next time.
Leave a Reply