import java.io.File;
import java.io.IOException;
import java.lang.Character.Subset;
import java.util.Collection;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang.StringUtils;

public class RemoveAllComment {

	@SuppressWarnings("unchecked")
	public static void main(String[] args) {

		File folder = new File("e:/project/j2se/src");
		Collection<File> fs = FileUtils.listFiles(folder,
				new String[] { "java" }, true);
		for (File f : fs) {

			try {
				StringBuilder sb = new StringBuilder();
				List<String> lines = FileUtils.readLines(f);
				for (String line : lines) {
					if (line.trim().startsWith("//"))
						continue;
//					if (line.contains(" //")){
//						line= line.substring(0, line.indexOf(" //"));
//					}
						
					sb.append(line).append("\r\n");

					FileUtils.writeStringToFile(f, sb.toString());

				}
			} catch (IOException e) {
				e.printStackTrace();
			}

		}

	}
}