Ok, I know in general a way to read text lines ony-by-one from a file into a
string variable.
But I miss somehow a short one-liner like:
foreach(String currentline : file("D:\test\myfile.txt")) {
....
}
Is there something like this in Java?
What would be the shortest way otherwise?
Robin
The problem with your one-liner example is that it provides
functionality good for scripting but bad for general purpose
programming. Java is a general purpose language so it needs more
descriptive coding.
final BufferedReader in= new BufferedReader(new FileReader("foo.txt"));
try
{
String line;
while ((line= in.readLine()) != null)
System.out.println(line);
}
finally
{
in.close();
}
Of course you can write your own Iterable that a for-each style loop
will accept. It's late and my mind is foggy so debugging and preventing
file descriptor leaks is up to you
for (String s : new LineReader(new File ("foo.txt")))
System.out.println(s);
class LineReader implements Iterable<String>
{
final File m_file;
LineReader (final File f)
{
m_file= f;
}
@Override
public Iterator<String> iterator()
{
try
{
final BufferedReader in=
new BufferedReader(new FileReader(m_file));
return new Iterator<String>()
{
String line= null;
@Override public boolean hasNext()
{
try
{
if (line == null)
line= in.readLine();
if (line == null)
{
in.close();
return false;
}
return true;
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
@Override public String next()
{
if (!hasNext())
throw new NoSuchElementException();
final String rv= line;
line= null;
return rv;
}
@Override
public void remove()
{
throw new UnsupportedOperationException();
}
};
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
}
