Please write the program in Java.
THE STRING BITS PROBLEM
Given a string, return a new string made of every other char starting with the first, so "Hello" yields "Hlo".
THE COUNT LETTERS PROBLEM
Return the total number of letter characters (alphabetical, case insensitive) that appear in the string. You must use the relational operators to determine if a character is a letter. You may not use the Character classification functions.
countLetters("7 52") returns 0
countLetters("abxx xc7") returns 6
THE STRING SPLOSION PROBLEM
Given a non-empty string like "Code", return a string like "CCoCodCode".
for input of "Code" returns "CCoCodCode"
for input of "abc" returns "aababc"
for input of "ab" returns "aab"
THE STRINGX PROBLEM
Given a string, return a version where all the "x*" have been removed. Except an "x*" at the very start or end should not be removed.
for input of "xxHxix" returns "xHix"
for input of "abxxxcd" returns "abcd"
for input of "xabxxxcdx" returns "xabcdx"
THE GOOD NUMBERS PROBLEM
Given a String, return a new String containing only the digit characters from the String. You must use the relational operators to determine if a character is a digit; you cannot use the Character classification methods.
goodNumbers("ab1c235") returns "1235"
goodNumbers("$2,12.50") returns "1250"
goodNumbers("Heeololeo") returns