Opening Firefox: multiple profile, multiple versions

This post answers two questions:

1. How to run multiple instances of Firefox, each using different profile?
2. How to run multiple versions of Firefox?

Running multiple instances of Firefox each using different profile:

Very easy. Just open notepad, paste below code, save it as batch (.bat) file, double click on batch file, you are done!

start "" "C:\Program Files\Mozilla Firefox\firefox.exe" -P default -no-remote

This opens Firefox with a "default" profile, which was created at the time of installing. To open with different profile just replace "default" with some other name. Very first time when you run this, as the new profile not exist yet, it allows you to create one. Create profile with same name what you have given in batch file, next time onwards it will use that profile automatically.

Tip: If you want to have multiple profiles and running batch file should ask you to select the profile, just don't create profile which has same name as you provided in batch file. This will make Firefox always to provide with an option of creating new profile or selecting existing one.

Running multiple versions of Firefox:

Even this is very easy, Install another version of Firefox in different location, create batch file as explained above, provide the correct path to Firefox executable folder, provide new profile name and you are done! So my new batch file might look like,

start "" "C:\Program Files\Mozilla Firefox2\firefox.exe" -P "ff2" -no-remote

Note: Opening profiles of one Firefox version in another version might create problems if you have Firefox addons installed. For example, if you create a profile "ff3" for Firefox 3 and install firebug in it, opening the same profile using Firefox 2 might stop you from using firebug.

Converting UTF-8 characters to HTML entities in Java

This function takes string as input and converts all special characters to its equivalent HTML entity code and returns newly built string.

HTML entity code conversion is done by extracting Unicode bits from character and combining it to build integer value which will be then combined with “&#” and “;” that is “&#” + integer value + “;”

Example:

Input string:

日本について - Japan

Output string:

日本について - Japan

Primary usage:

If you have a web page in which content type of the page is set to other than UTF-8 and if you want to display any UTF-8 characters in that page those characters not displayed properly. To solve this, you can convert those UTF-8 characters to HTML entity codes using this function and display it as the content type of page will have no effect on these HTML Entity codes.

Code:

public static String buildHtmlEntityCode(String input) {
    StringBuffer output = new StringBuffer(input.length() * 2);

    int len = input.length();
    int code,code1,code2,code3,code4;
    char ch;

    for( int i=0; i<len; ) {
        code1 = input.codePointAt(i);
        if( code1 >> 3 == 30 ){
            code2 = input.codePointAt(i + 1);
            code3 = input.codePointAt(i + 2);
            code4 = input.codePointAt(i + 3);
            code = ((code1 & 7) << 18) | ((code2 & 63) << 12) | ((code3 & 63) << 6) | ( code4 & 63 );
            i += 4;
            output.append("&#" + code + ";");
        }
        else if( code1 >> 4 == 14 ){
            code2 = input.codePointAt(i + 1);
            code3 = input.codePointAt(i + 2);
            code = ((code1 & 15) << 12) | ((code2 & 63) << 6) | ( code3 & 63 );
            i += 3;
            output.append("&#" + code + ";");
        }
        else if( code1 >> 5 == 6 ){
            code2 = input.codePointAt(i + 1);
            code = ((code1 & 31) << 6) | ( code2 & 63 );
            i += 2;
            output.append("&#" + code + ";");
        }
        else {
            code = code1;
            i += 1;

            ch = (char)code;
            if (ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9') {
                output.append(ch);
            }
            else {
                output.append("&#" + code + ";");
            }
        }
    }

    return output.toString();
}