private IdGenerator createParameterizableIdGenerator(String expression) {
Assert.hasText(expression);
int paramIndex = expression.indexOf(PARAM_DELIM);
if (paramIndex == -1) {
// no parameters
throw new IllegalArgumentException(expression + " is not valid expression.");
}
String name = expression.substring(0, paramIndex).trim();
String parameters = expression.substring(paramIndex + 1, expression.length() - 1);
ParameterEntry[] paramEntries = getParameterEntries(parameters);
Class idGenClass = (Class) GENERATORS.get(name);
if (idGenClass == null) {
// custom implement
idGenClass = ClassLoaderUtils.loadClass(name, PatternParser.class);
}
IdGenerator generator = (IdGenerator) ClassLoaderUtils.instantiate(idGenClass);
for (int i = 0; i < paramEntries.length; i++) {
try {
// need type convertion
BeanUtils.setProperty(generator, paramEntries[i].getName(), paramEntries[i].getValue());
} catch (IllegalAccessException e) {
throw new IdGenerationException(expression + " is not valid expression.", e);
} catch (InvocationTargetException e) {
throw new IdGenerationException(expression + " is not valid expression.", e);
}
}
return generator;
}
public ParameterEntry(String nameValuePair) {
String[] pairs = nameValuePair.split("=");
Assert.isTrue(pairs.length == 2);
this.name = pairs[0].trim();
this.value = pairs[1].trim();
}