The camel case completion is very useful.
But frequently, tremendous candidate appears and there is no way to narrow them.
So, I tried to customize NetBeans to narrow candidates of camel case completion 
by inputing lower character. 
It is very nice.

The source modified is shown bellow.

/java/editor/src/org/netbeans/modules/editor/java/JMIUtils.java
819:
java.util.regex.Pattern pat = java.util.regex.Pattern.compile("([A-Z]+)([^A-Z]*)
");
java.util.regex.Matcher mat = pat.matcher(name);        
boolean camelCase = mat.matches();
String up = "";
String lo = "";
if(camelCase){
	up = mat.group(1);
	lo = mat.group(2);
}

846:
if (!startsWith(featureName, name) && (!camelCase || !(feature instanceof 
JavaClass) || !matchesCamelCaseEx(featureName, up, lo))) continue;

1171:
public static boolean matchesCamelCaseEx(String simpleName, String up, String 
lo) {
    int sni;
    int pi;
    for (pi = 0, sni = 0; sni < simpleName.length() && pi < up.length(); sni++) 
{
        char ch = simpleName.charAt(sni);
        if (Character.isUpperCase(ch)) {
            if (ch != up.charAt(pi++)) {
                return false;
            }
        }
    }
    
    if(pi != up.length()) return false;
    
    if(lo.length() > 0){
        if(!simpleName.substring(sni).startsWith(lo)){
            return false;
        }
    }
    return true;
}

/java/editor/src/org/netbeans/modules/editor/java/JavaCompletionProvider.java
159:
java.util.regex.Pattern pat = java.util.regex.Pattern.compile("([A-Z]+)([^A-Z]*)
");
java.util.regex.Matcher mat = pat.matcher(prefix);        
boolean camelCase = mat.matches();
String up = "";
String lo = "";
if(camelCase){
	up = mat.group(1);
	lo = mat.group(2);
}

163:
|| (camelCase && (itm instanceof NbJMIResultItem.ClassResultItem) && JMIUtils.
matchesCamelCaseEx(itm.getItemText(), up, lo)))