import java.io.*;
import java.lang.*;
import java.net.*;

public class DirList 
{


    public static String raw_filename_to_url_encoded(String fileName) 
    {
	String urlEncoded = "";
	try {
	    byte[] bytes = fileName.getBytes();
	    
	    for(int i = 0; i < bytes.length; i++) {
		// mask each byte (by applying & 0xFF) to make the signed
		// byte (in the range -128 to 127) unsigned (in the range
		// 0 to 255).

		int byteVal = (int)(bytes[i] & 0xFF);
		
		if(byteVal > 127) {
		    urlEncoded += String.format("%%%02X", (int)byteVal);
		} else {
		    urlEncoded += String.format("%c",(char)byteVal);
		}
	    }
	}
	catch (Exception e) {
	    e.printStackTrace();
	}

	return urlEncoded;
    }

    public static String iso_8859_1_filename_to_url_encoded(String raw_bytes_filename) 
    {
	String urlEncoded = "";

	try {
	    // By this point we have a UTF-8 encoded string that captures
	    // what the ISO-8859-1 (Latin-1) character is that corresponded to the
	    // 8-bit numeric value for that character in the filename
	    // on the file system
	    
	    // For example:
	    //   File system char:             <lower-case beta char in Latin-7> = %E2
	    //   Equivalent Latin 1 char:      <lower-case a with circumflex>    = %E2
	    //   Mapped to UTF-8:              <lower-case a with circumflex>    = <C3><A2>

	    // Our task is to take the string the contains <C3><A2> and ensure that
	    // we "see" it as <E2>

	    byte [] raw_bytes = raw_bytes_filename.getBytes("ISO-8859-1");
	    String unicode_filename = new String(raw_bytes,"UTF-8");
	    
	    for(int i = 0; i < unicode_filename.length(); i++) {
		char charVal = unicode_filename.charAt(i);
		if((int)charVal > 127) {
		    urlEncoded += String.format("%%%02X", (int)charVal);
		} else {
		    urlEncoded += String.format("%c",(char)charVal);
		}
	    }
	}
	catch (Exception e) {
	    e.printStackTrace();
	}

	return urlEncoded;
    }


    public static void main(String[] args) 
    {
	
	String file_encoding = System.getProperty("file.encoding");
	String file_encoding_pkg = System.getProperty("file.encoding.pkg");

	String sun_io_unicode_encoding = System.getProperty("sun.io.unicode.encoding");
	String sun_jnu_encoding = System.getProperty("sun.jnu.encoding");

	System.out.println("===========================");
	System.out.println("file.encoding:           " + file_encoding);
	System.out.println("file.encoding.pkg:       " + file_encoding_pkg);
	System.out.println("sun_io_unicode_encoding: " + sun_io_unicode_encoding);
	System.out.println("sun_jnu_encoding:        " + sun_jnu_encoding);
	System.out.println("===========================");

	if (args.length>0) {

	    File folder = new File(args[0]);
	    File[] listOfFiles = folder.listFiles();
	    
	    for (int i = 0; i < listOfFiles.length; i++) {
		
		File dir_or_file = listOfFiles[i];
		URI  df_uri = dir_or_file.toURI();
		String df_ascii = df_uri.toASCIIString();
		System.out.println("Before file test, toASCII URI: " + df_ascii);
		
		if (listOfFiles[i].isFile()) {
		    File file = listOfFiles[i];
		    URI  filename_uri = file.toURI();
		    
		    try {
			// The trick:
			//  1. toASCIIString() will %xx encode values > 127
			//  2. Decode the result to "ISO-8859-1" 
			//  3. URL encode the bytes to string
			
			// Step 2 forces the string to be 8-bit values.  It
			// doesn't matter if the starting raw filename was *not*
			// in the ISO-8859-1 encoding, the effect is to ensure
			// we have an 8-bit byte string that (numerically)
			// captures the right value.  These numerical values are
			// then used to determine how to URL encode it
			
			String filename_ascii = filename_uri.toASCIIString();
			String filename_raw_bytes = URLDecoder.decode(filename_ascii,"ISO-8859-1");
			String filename_url_encoded = iso_8859_1_filename_to_url_encoded(filename_raw_bytes);
			
			filename_url_encoded = filename_url_encoded.replaceAll(" ","%20");
			
			System.out.println("File " + filename_url_encoded);
			
			try {
			    File test_file = new File(new URI(filename_url_encoded.replaceAll(" ","%20")));
			    if (test_file.exists()) {
				System.out.println("   ... and I can see it!!!");
			    }
			}
			catch (Exception e) {
			    e.printStackTrace();
			}
			
			
		    }
		    catch (Exception e) {
			e.printStackTrace();
		    }
		} else if (listOfFiles[i].isDirectory()) {
		    File sub_folder = listOfFiles[i];
		    System.out.println("Directory " + sub_folder.getName());
		}
	    }
	}
    }

}