"James Carman" <[EMAIL PROTECTED]> writes:
>I would say that this is something that would be very useful. We did
>something similar in HiveMind. I can imagine an implementation like:
I always wondered over the obsession with startsWith() and endsWith()
in string-related commons code. These operations are hugely expensive,
especially with long strings to check!
They are implemented using a loop and char compares. I very much
prefer using charAt and length() for this; both are constant time
operations.
Same goes to the mixture of StringBuffer operations and '+'. Finally
append()'ing a char is (at least in the Sun 1.4.x JSDK) more effective
than append()'ing a String.
Your implementation also throws NPE for className == null BTW. There
is also the pathological case of ClassUtils.enhancedForName("[]").
Currently this throws CNF for class '['.
How about this:
--- cut ---
private static Map typeMap = new HashMap();
private static Map abbreviationMap = new HashMap();
static
{
typeMap.put( "int", Integer.TYPE );
typeMap.put( "boolean", Boolean.TYPE );
typeMap.put( "float", Float.TYPE );
typeMap.put( "long", Long.TYPE );
typeMap.put( "short", Short.TYPE );
typeMap.put( "byte", Byte.TYPE );
typeMap.put( "double", Double.TYPE );
typeMap.put( "char", Character.TYPE );
abbreviationMap.put( "int", "I" );
abbreviationMap.put( "boolean", "Z" );
abbreviationMap.put( "float", "F" );
abbreviationMap.put( "long", "J" );
abbreviationMap.put( "short", "S" );
abbreviationMap.put( "byte", "B" );
abbreviationMap.put( "double", "D" );
abbreviationMap.put( "char", "C" );
}
public static Class enhancedForName(String className)
throws ClassNotFoundException
{
Class clazz = null;
if (className != null)
{
clazz = typeMap.get(className);
if (clazz == null)
{
int nameLen = className.length();
StringBuffer actualNameBuffer = new StringBuffer();
boolean foundArray = false;
while(namelen > 2
&& className.charAt(nameLen - 2) == '['
&& className.charAt(nameLen - 1) == ']')
{
actualNameBuffer.append('[');
nameLen -= 2;
foundArray = true;
}
if (!foundArray)
{
clazz = Class.forName(className);
}
else
{
final String abbreviation = (String)
abbreviationMap.get(className);
if (abbreviation != null)
{
actualNameBuffer.append(abbreviation);
}
else
{
actualNameBuffer.append('L')
.append(className)
.append(';');
}
clazz = Class.forName(actualNameBuffer.toString());
}
}
}
return clazz;
}
--- cut ---
Best regards
Henning
>public static Class enhancedForName( String className ) throws
>ClassNotFoundException
>{
> Class clazz = ( Class )typeMap.get( className );
> if( clazz == null )
> {
> if( className.endsWith( "[]" ) )
> {
> final StringBuffer actualNameBuffer = new StringBuffer();
> while( className.endsWith( "[]" ) )
> {
> className = className.substring( 0, className.length() - 2 );
> actualNameBuffer.append( "[" );
> }
> final String abbreviation = ( String )abbreviationMap.get( className
>);
> if( abbreviation != null )
> {
> actualNameBuffer.append( abbreviation );
> }
> else
> {
> actualNameBuffer.append( "L" + className + ";" );
> }
> clazz = Class.forName( actualNameBuffer.toString() );
> }
> else
> {
> clazz = Class.forName( className );
> }
> }
> return clazz;
>}
>-----Original Message-----
>From: Thomas Dudziak [mailto:[EMAIL PROTECTED]
>Sent: Monday, September 05, 2005 5:05 PM
>To: Jakarta Commons Developers List
>Subject: [lang] enhanced version of Class.forName
>Hi folks,
>I had this problem that I needed to create class objects for things
>like "int" and "boolean", eg. the type specification that you would
>use for a variable declaration or method parameter.
>Since the normal Class.forName does not handle this really well, and
>commons-lang does not provide such a function (please correct me if
>I'm wrong here), I implemented it myself.
>Now I wonder, would this be useful enhancement to ClassUtils ? If so,
>I could provide a patch in BugZilla.
>regards,
>Tom
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