Using VIM to fix badly formatted code - vim

Question

Ihave this piece of code that i need to 'format/indent'.. Can you please suggest a fix?
import java.io.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; public class PrimeSearcher extends HttpServlet implements Runnable { long lastprime = 0; // last prime found Date lastprimeModified = new Date(); // when it was found Thread searcher; // background search thread public void init(ServletConfig config) throws ServletException { super.init(config); // always! searcher = new Thread(this); searcher.setPriority(Thread.MIN_PRIORITY); // be a good citizen searcher.start(); } public void run() { // QTTTBBBMMMTTTOOO long candidate = 1000000000000001L; // one quadrillion and one // Begin loop searching for primes while (true) { // search forever if (isPrime(candidate)) { lastprime = candidate; // new prime lastprimeModified = new Date(); // new "prime time" } candidate += 2; // evens aren't prime // Between candidates take a 0.2 second break. // Another way to be a good citizen with system resources. try { searcher.sleep(200); } catch (InterruptedException ignored) { } } } private static boolean isPrime(long candidate) { // Try dividing the number by all odd numbers between 3 and its sqrt double sqrt = Math.sqrt(candidate); for (long i = 3; i <= sqrt; i += 2) { if (candidate % i == 0) return false; // found a factor } // Wasn't evenly divisible, so it's prime return true; } public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType("text/plain"); PrintWriter out = res.getWriter(); if (lastprime == 0) { out.println("Still searching for first prime..."); } else { out.println("The last prime discovered was " + lastprime); out.println(" at " + lastprimeModified); } } public void destroy() { searcher.stop(); } }

Answer 1

Break lines around brackets:
:%s/[{}]/\r&\r/g
Break lines after semicolons:
:%s/;/&\r/g
Remove empty lines:
:g/^\s*$/d
Indent:
:set ft=java
gg=G
After this, you need to tweak the code just a little to split comments.
import java.io.;
import java.util.;
import javax.servlet.;
import javax.servlet.http.;
public class PrimeSearcher extends HttpServlet implements Runnable
{
long lastprime = 0;
// last prime found Date lastprimeModified = new Date();
// when it was found Thread searcher;
// background search thread public void init(ServletConfig config) throws ServletException
{
super.init(config);
// always! searcher = new Thread(this);
searcher.setPriority(Thread.MIN_PRIORITY);
// be a good citizen searcher.start();
}
public void run()
{
// QTTTBBBMMMTTTOOO long candidate = 1000000000000001L;
// one quadrillion and one // Begin loop searching for primes while (true)
{
// search forever if (isPrime(candidate))
{
lastprime = candidate;
// new prime lastprimeModified = new Date();
// new "prime time"
}
candidate += 2;
// evens aren't prime // Between candidates take a 0.2 second break. // Another way to be a good citizen with system resources. try
{
searcher.sleep(200);
}
catch (InterruptedException ignored)
{
}
}
}
private static boolean isPrime(long candidate)
{
// Try dividing the number by all odd numbers between 3 and its sqrt double sqrt = Math.sqrt(candidate);
for (long i = 3;
i <= sqrt;
i += 2)
{
if (candidate % i == 0) return false;
// found a factor
}
// Wasn't evenly divisible, so it's prime return true;
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
{
res.setContentType("text/plain");
PrintWriter out = res.getWriter();
if (lastprime == 0)
{
out.println("Still searching for first prime...");
}
else
{
out.println("The last prime discovered was " + lastprime);
out.println(" at " + lastprimeModified);
}
}
public void destroy()
{
searcher.stop();
}
}

Answer 2

You could at least start by replacing all ; with a ; + line-break:
:%s/;/;\n\r/g
Then you could replace all { with { + line-break:
:%s/{/{\n\r/g
Then replace all } with } + line-break:
:%s/}/}\n\r/g
This will get you started. You'd still have to clean up all the indentation. Too bad there isn't ReSharper for Java (that I know of anyway).

Answer 3

Use:
http://www.prettyprinter.de/
import java.io.;
import java.util.;
import javax.servlet.;
import javax.servlet.http.;
public class PrimeSearcher extends HttpServlet implements Runnable {
long lastprime = 0;
// last prime found Date lastprimeModified = new Date();
// when it was found Thread searcher;
// background search thread public void init(ServletConfig config) throws ServletException {
super.init(config);
// always! searcher = new Thread(this);
searcher.setPriority(Thread.MIN_PRIORITY);
// be a good citizen searcher.start();
}
public void run() {
// QTTTBBBMMMTTTOOO long candidate = 1000000000000001L;
// one quadrillion and one // Begin loop searching for primes while (true) {
// search forever if (isPrime(candidate)) {
lastprime = candidate;
// new prime lastprimeModified = new Date();
// new "prime time"
}
candidate += 2;
// evens aren't prime // Between candidates take a 0.2 second break. // Another way to be a good citizen with system resources. try {
searcher.sleep(200);
}
catch (InterruptedException ignored) {
}
}
}
private static boolean isPrime(long candidate) {
// Try dividing the number by all odd numbers between 3 and its sqrt double sqrt = Math.sqrt(candidate);
for (long i = 3;
i <
= sqrt;
i += 2) {
if (candidate % i == 0) return false;
// found a factor
}
// Wasn't evenly divisible, so it's prime return true;
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
res.setContentType("text/plain");
PrintWriter out = res.getWriter();
if (lastprime == 0) {
out.println("Still searching for first prime...");
}
else {
out.println("The last prime discovered was " + lastprime);
out.println(" at " + lastprimeModified);
}
}
public void destroy() {
searcher.stop();
}
}
Tweak the settings to get it looking how you want.

Answer 4

Probably you best proceed as following:
Add line breaks after characters like ;, { and }:
:s/[;{}]/\0\r/g
Go through the code and fix bad line breaks. For example comment lines started with // don't usually end in some special character and will need manual splitting
Fix the indentation with =. Use it with some movement command like =G or select the code in visual mode and then hit = to indent it.