A DESCRIPTION OF THE REQUEST :
 java.lang.String.replaceAll(String target,String replacement) needs improvement in execution time based on my test and suggestion

JUSTIFICATION :
While Testing, I found out that the execution time of java.lang.String.replaceAll(target, replacement) function can be improved by up to 80% if all 100% characters in String are to be replaced, and 40% increase in execution time if 50% characters are to be replaced.


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public class Test{

public static String replace(String source, String target, String replacement){
        String newString = "";
        boolean replace;
        for(int count = 0, targetLength = target.length(); count < source.length(); ){
            replace = (source.substring(count, targetLength).equals(target));
            if(replace){
                 //Instead of counting characters that are found, we can easily jump through them by adding there length
                newString += replacement;
                targetLength += target.length();
                count += target.length();
            }else{
                //Here every character is counted. It is needed when there is no match
                newString += source.charAt(count);
                count++;
                targetLength ++;
            }
            int x = 0;
        }
        return newString;
    }

public static void compareTime(String source, String target, String replacement){
        //Creates java execution time of replaceAll
        long javaTime1 = System.nanoTime();
        System.out.println("java replaceAll() has replaced : " + source );
        System.out.println("with : " + source.replace(target, replacement));
        long javaTime2 = System.nanoTime();
         System.out.println("**************************************************************");
       //Creates my execution time
        long time1 = System.nanoTime();
        replace(source,target,replacement);
        long time2 = System.nanoTime();
        System.out.println("function replace() has replaced : " + source );
        System.out.println("with : " + source.replace(target, replacement));
        
        System.out.println("**************************************************************");
        
         System.out.println("Java Time : " + (javaTime2 - javaTime1));
        System.out.println("function Time: " + (time2 - time1));
    }
public static void main (String[]args){
Test.compareTime("Tast to chack tima axacution", "a", "e");
}
}
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