How to recognize empty lines in a source file

Question

Hi to all
I want to count he empty lines in a source file. I've been using the methods provided by String such as "contains" ecc but for example
String line = new String();
line.startsWith(\r); in order to trace the carrage return in order to consider this as an empty line didn't work
I cut and paste here my code any hint is apreciable!
import java.io.*;
public class Filereader {
public Filereader() {
public static void main(String argv[]) {
File temp = new File("LOC.txt");
File list = new File("mylist.txt");
String line = new String();
String lineinternal = new String();
int linecounter = 0;
int sourcelines = 0;
int commentlines = 0;
int complexlines = 0;
boolean commentflag = false;
try {
FileReader fileinput = new FileReader(list);
BufferedReader buffinput = new BufferedReader(fileinput);
FileWriter fileout = new FileWriter(temp);
BufferedWriter out = new BufferedWriter(fileout);
out.append("NOME");
out.append(" \t");
out.append("LOC");
out.append(" \t");
out.append("LCom");
out.append(" \t");
out.append("Ltot");
out.newLine();
boolean eof = false;
boolean eofinternal;
while ( !eof ) {
eofinternal = false;
line = buffinput.readLine();
if ( line != null ) {
linecounter = 0;
sourcelines = 0;
commentlines = 0;
complexlines = 0;
FileReader fileinternal = new FileReader(line);
BufferedReader buffinternal = new BufferedReader(fileinternal);
while ( !eofinternal ) {
lineinternal = buffinternal.readLine();
if ( lineinternal != null ) {
linecounter++;
if ( lineinternal.contains("//") && (!commentflag) )
commentlines++;
if ( lineinternal.contains("/*") )
commentflag = true;
if ( commentflag )
commentlines++;
if ( lineinternal.contains("*/") )
commentflag = false;
if ( !commentflag ) {
if ( (lineinternal.contains(";")) && (lineinternal.contains("//")) && (!lineinternal.startsWith("//")) )
complexlines++;
else
if ( (lineinternal.contains(";")) && (lineinternal.contains("/*")) && (!lineinternal.startsWith("/*")) )
complexlines++;
else
if ( (lineinternal.contains(")")) && (lineinternal.contains("//")) && (!lineinternal.startsWith("//")) )
complexlines++;
else
if ( (lineinternal.contains(")")) && (lineinternal.contains("/*")) && (!lineinternal.startsWith("/*")) )
complexlines++;
else
if ( (lineinternal.contains("}")) && (lineinternal.contains("//")) && (!lineinternal.startsWith("//")) )
complexlines++;
else
if ( (lineinternal.contains("}")) && (lineinternal.contains("/*")) && (!lineinternal.startsWith("/*")) )
complexlines++;
else
eofinternal = true;
buffinternal.close();
sourcelines = (linecounter - commentlines) + complexlines;
Integer data1 = new Integer(sourcelines);
Integer data2 = new Integer(commentlines);
Integer data3 = new Integer(linecounter);
String f = data1.toString();
out.append(line);
out.append(" \t");
out.append(data1.toString());
out.append(" \t");
out.append(data2.toString());
out.append(" \t");
out.append(data3.toString());
out.newLine();
else {
eof = true;
buffinput.close();
out.close();
System.out.println("...end of try catch ");
catch (IOException e) {
System.out.println("Error..." + e.toString());
catch (Exception e) {
System.out.println("Error..." + e.toString());
Thanks in advance to all
Mandy

Answer 1

Try this:
String trimmedLine = lineFromFile.trim();
if ("".equals(trimmedLine))
    // logic for trimmed line
}That's some ugly procedural code. Long "if/else if/else" is a very bad sign.
I'd advise that you at least move this mess out of main() and into a method that you could just call. I don't know if this will be reusable or not, but you won't have a chance of it being callable in another context if you leave it all in main().
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