Best way to implement extension to String

Question

I have an webapp that displays data taken from a database, and I have lots of Strings that need to be tweaked for HTML display. For example, I want to replace Ca2+ with Ca²⁺.
So currently I have a static method that takes care of this
public static String formatForHTML(String input) {
        input = input.replace("Ca2+", "Ca²⁺");
        input = input.replace("Cs+", "Cs⁺");
      etc etc
        return input;
    }which gets called from various places:
public String getComments() {
        return Format.formatForHTML(comments);
    }I feel that a better way of doing this would be to make a lightweight class - essentially I want to do something like this
public class SpecialString extends String{
public String formatNicely{
  String temp = this;
  temp = temp.replace("Ca2+", "Ca²⁺");
  etc.
  return temp;
}This would allow me to do this
SpecialString s = "An interesting ion is Ca2+";
out.println(s.formatNicely());While still allowing me to use all the String methods
int length = s.length();
String start = s.subString(0,3);I know that String is final, so I can't do the above. The obvious thing is to make a lightweight class that uses a String internally
public class SpecialString{
    private String s;
    public SpecialString(String init){
    this.s = init;
    public String formatNicely(){
        String temp = s;
        temp = temp.replace("Ca2+", "Ca²⁺");
        etc.
        return temp;
}This is fine, and allows me to do
SpecialString s = "An interesting ion is Ca2+";
out.println(s.formatNicely());BUT I now don't have access to all the other String methods
SpecialString s = "An interesting ion is Ca2+";
int length = s.length();  // no such methodI can add an accessor
public class SpecialString{
    private String s;
    public SpecialString(String init){
    this.s = init;
    public String formatNicely(){
        String temp = s;
        temp = temp.replace("Ca2+", "Ca²⁺");
        etc.
        return temp;
    public String getSpecialString(){
       return this.s;
}and now call
SpecialString s = "An interesting ion is Ca2+";
int length = s.getSpecialString().length();  // OK nowOR I can manually add methods to my SpecialString class
public class SpecialString{
    private String s;
    public SpecialString(String init){
    this.s = init;
    public String formatNicely(){
        String temp = s;
        temp = temp.replace("Ca2+", "Ca²⁺");
        etc.
        return temp;
    public int length(){
         return this.s.length();
}and call
SpecialString s = "An interesting ion is Ca2+";
int length = s.length();  // also OKBoth of these solutions seem like a lot of extra code. Is this just a feature of the Java that I have to live with, or is there a better way to do this?

Answer 1

mojones wrote:
I have an webapp that displays data taken from a database, and I have lots of Strings that need to be tweaked for HTML display. For example, I want to replace Ca2+ with Ca²⁺.
So currently I have a static method that takes care of this
public static String formatForHTML(String input) {
input = input.replace("Ca2+", "Ca²⁺");
input = input.replace("Cs+", "Cs⁺");
etc etc
return input;
}which gets called from various places:
public String getComments() {
return Format.formatForHTML(comments);
}I feel that a better way of doing this would be to make a lightweight class - essentially I want to do something like this
public class SpecialString extends String{
public String formatNicely{
String temp = this;
temp = temp.replace("Ca2+", "Ca²⁺");
etc.
return temp;
}This would allow me to do this
SpecialString s = "An interesting ion is Ca2+";
out.println(s.formatNicely());While still allowing me to use all the String methods
int length = s.length();
String start = s.subString(0,3);I know that String is final, so I can't do the above. The obvious thing is to make a lightweight class that uses a String internally
public class SpecialString{
private String s;
public SpecialString(String init){
this.s = init;
public String formatNicely(){
String temp = s;
temp = temp.replace("Ca2+", "Ca²⁺");
etc.
return temp;
}This is fine, and allows me to do
SpecialString s = "An interesting ion is Ca2+";
out.println(s.formatNicely());BUT I now don't have access to all the other String methods
SpecialString s = "An interesting ion is Ca2+";
int length = s.length();  // no such methodI can add an accessor
public class SpecialString{
private String s;
public SpecialString(String init){
this.s = init;
public String formatNicely(){
String temp = s;
temp = temp.replace("Ca2+", "Ca²⁺");
etc.
return temp;
public String getSpecialString(){
return this.s;
}and now call
SpecialString s = "An interesting ion is Ca2+";
int length = s.getSpecialString().length();  // OK nowOR I can manually add methods to my SpecialString class
public class SpecialString{
private String s;
public SpecialString(String init){
this.s = init;
public String formatNicely(){
String temp = s;
temp = temp.replace("Ca2+", "Ca²⁺");
etc.
return temp;
public int length(){
return this.s.length();
}and call
SpecialString s = "An interesting ion is Ca2+";
int length = s.length();  // also OKBoth of these solutions seem like a lot of extra code. Is this just a feature of the Java that I have to live with, or is there a better way to do this?you could store into the database both strings- one without the html and another with the html