Connection String for different Databases

A very good link:

http://www.connectionstrings.com/

Converting char to String in Java

public class ConvertCharToString {
 
 public static void main(String[] args) { 

        String name = "Sardar"; 

        //get the first character from the string

        char firstChar = name[0];

        // convert the character to string again
        String temp = Character.toString(firstChar);

        // check if the char is converted correctly 
        if ( "S".equals(temp) )
        {
            System.out.println("String Matched");
        }
     }

}

Count and Display non empty lines in a file Java

Count and Display nun empty lines in a file Java

public class FileLineCounter
{
    public static int countAndDisplayNonEmptyLines(String path) throws IOException
    {
        int lineCount = 0;
        InputStream is = null;
        try
        {
            is = new FileInputStream(path);
            InputStreamReader in = new InputStreamReader(is);
            BufferedReader _input = new BufferedReader(in);

            String line = _input.readLine();
            while ( line != null )
            {
                if ( !line.trim().isEmpty() )
                {
                    System.out.println(lineCount + ". " + line);
                    lineCount++;
                }
                line = _input.readLine();
            }
        }
        finally
        {
            if ( is != null )
                is.close();
        }
        return lineCount;
    }

    public static void main(String args[])
    {
        try
        {
            countAndDisplayNonEmptyLines("C:\\Users\\Desktop\\help.log");
        }
        catch ( IOException e )
        {
            e.printStackTrace();
        }
    }
}

Get words or characters from a string Java

Get all the words in a string in a simple java program.

  public List  getWords(String line)
    {
     char delimiter = ' ';
     StringTokenizer tokenizer = new StringTokenizer(line, delimiter );
     if ( tokenizer == null )
            return null;

     List result = new ArrayList();

     while ( tokenizer.hasMoreTokens() )
           result.add(tokenizer.nextToken());

     return result;
    }

Count number of Characters in a word

public static int countCharacters(String str)
    {
        int charCount = 0;

        if ( str == null || str.trim().isEmpty() )
            return charCount;

        int length = str.length();
        for ( int i = 0; i < length; i++ )
        {
            if ( str.charAt(i) != ' ' )
                charCount++;
        }
        return charCount;
    }

public static void main(String[] args)
{
        String word = "LI FE";
        System.out.println("Number of characters in '" + word + "' = " + countCharacters(word));
}

Counting number of spaces at the beginning of the string JAVA

Count the number of spaces at the beginning of a string in a Java program
   
private int countSpaces(String s)
    {
        int spaceCount = 0;
        if ( s == null || s.trim().isEmpty() )
            return spaceCount;

        int length = s.length();
        for ( int i = 0; i < length; i++ )
        {
            if ( s.charAt(i) == ' ' )
                spaceCount++;
            else
                break;
        }
        return spaceCount;
    }

Sorting List or Lists in Java

Sorting a List> using Collections.sort(List, Comparator)
Example Program:

List> persons;

Collections.sort(persons, new Comparator>()
        {

            @Override
            public int compare(List o1, List o2)
            {
                if ( o1 == null || o2 == null || o1.size() == 0 || o2.size() == 0 )
                    return 0;

                Person item1 = o1.get(0);
                Person item2 = o2.get(0);
                if ( item1 == null )
                {
                    int size = o1.size();
                    for ( int i = 1; i < size; i++ )
                    {
                        item1 = o1.get(i);
                        if ( item1 != null )
                            break;
                    }
                }
                if ( item2 == null )
                {
                    int size = o2.size();
                    for ( int i = 1; i < size; i++ )
                    {
                        item2 = o2.get(i);
                        if ( item2 != null )
                            break;
                    }
                }
                Date d1 = null;
                Date d2 = null;
                if ( item1 != null )
                    d1 = new Date(item1.getTime());
                if ( item2 != null )
                    d2 = new Date(item2.getTime());
                int result = 0;
                if ( d1 != null && d2 != null )
                {
                    if ( d1.before(d2) )
                        result = 1;
                    else if ( d1.after(d2) )
                        result = -1;
                }
                return result;
            }

        });