>01 public static String escapeString (String str) {
>02
>03 int escCount = 0;
>04 int len = str.length();
>05 char c;
>06
>07 // Count number of chars that need escaping.
>08 for (int i=0; i<len; i++) {
>09 c = str.charAt(i);
>10 if (c == '\\' || c == '\"')
>11 escCount++;
>12 }
>13
>14 if (escCount > 0) {
>15
>16 StringBuffer buf = new StringBuffer(str.length() + escCount); // !
>17
>18 for ( int idx = 0; idx < str.length(); idx++ ) { // !
>19 char ch = str.charAt( idx );
>20 switch ( ch ) {
>21 case '"': buf.append( "\\\"" ); break; // !
>22 case '\\': buf.append( "\\\\" ); break; // !
>23 default: buf.append( ch ); break;
>24 }
>25 }
>26
>27 return buf.toString();
>28 }
>29 else
>30 return str;
>31 }
Hi,
Here are 2 remarks :
1. : line (16,18)
You define the field 'len' but you don't use it everywhere.
So you have lot's of function calls (str.length()).
2. :line (21,22)
If you look at the source of java.lang.StringBuffer it seems that
buf.append( '\\' ).append( '\"' ); is cheaper than a
buf.append( "\\\"" );
java.lang.StringBuffer :
public synchronized StringBuffer append(char c) {
int newcount = count + 1;
if (newcount > value.length)
expandCapacity(newcount);
value[count++] = c;
return this;
}
public synchronized StringBuffer append(String str) {
if (str == null) {
str = String.valueOf(str);
}
int len = str.length(); // !
int newcount = count + len;
if (newcount > value.length)
expandCapacity(newcount); // !
str.getChars(0, len, value, count);
count = newcount;
return this;
}
Regards,
Ralf
