Obtains all property descriptors from a bean (interface or implementation).
//package com.witframework.util;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Obtains all property descriptors from a bean (interface or implementation).
* <p>
* The java.beans.Introspector does not process the interfaces hierarchy chain, this one does.
* <p>
* @author Alejandro Abdelnur
*
*/
public class BeanIntrospector {
private static final Map _introspected = new HashMap();
public static synchronized PropertyDescriptor[] getPropertyDescriptors(Class klass) throws IntrospectionException {
PropertyDescriptor[] descriptors = (PropertyDescriptor[]) _introspected.get(klass);
if (descriptors==null) {
descriptors = getPDs(klass);
_introspected.put(klass,descriptors);
}
return descriptors;
}
private static PropertyDescriptor[] getPDs(Class klass) throws IntrospectionException {
Method[] methods = klass.getMethods();
Map getters = getPDs(methods,false);
Map setters = getPDs(methods,true);
List pds = merge(getters,setters);
PropertyDescriptor[] array = new PropertyDescriptor[pds.size()];
pds.toArray(array);
return array;
}
private static final String SETTER = "set";
private static final String GETTER = "get";
private static final String BOOLEAN_GETTER = "is";
private static Map getPDs(Method[] methods,boolean setters) throws IntrospectionException {
Map pds = new HashMap();
for (int i=0;i<methods.length;i++) {
String pName = null;
PropertyDescriptor pDescriptor = null;
if ((methods[i].getModifiers()&Modifier.PUBLIC)!=0) {
if (setters) {
if (methods[i].getName().startsWith(SETTER) &&
methods[i].getReturnType()==void.class && methods[i].getParameterTypes().length==1) {
pName = Introspector.decapitalize(methods[i].getName().substring(3));
pDescriptor = new PropertyDescriptor(pName,null,methods[i]);
}
}
else {
if (methods[i].getName().startsWith(GETTER) &&
methods[i].getReturnType()!=void.class && methods[i].getParameterTypes().length==0) {
pName = Introspector.decapitalize(methods[i].getName().substring(3));
pDescriptor = new PropertyDescriptor(pName,methods[i],null);
}
else
if (methods[i].getName().startsWith(BOOLEAN_GETTER) &&
methods[i].getReturnType()==boolean.class && methods[i].getParameterTypes().length==0) {
pName = Introspector.decapitalize(methods[i].getName().substring(2));
pDescriptor = new PropertyDescriptor(pName,methods[i],null);
}
}
}
if (pName!=null) {
pds.put(pName,pDescriptor);
}
}
return pds;
}
private static List merge(Map getters,Map setters) throws IntrospectionException {
List props = new ArrayList();
Set processedProps = new HashSet();
Iterator gs = getters.keySet().iterator();
while (gs.hasNext()) {
String name = (String) gs.next();
PropertyDescriptor getter = (PropertyDescriptor) getters.get(name);
PropertyDescriptor setter = (PropertyDescriptor) setters.get(name);
if (setter!=null) {
processedProps.add(name);
PropertyDescriptor prop = new PropertyDescriptor(name,getter.getReadMethod(),setter.getWriteMethod());
props.add(prop);
}
else {
props.add(getter);
}
}
Set writeOnlyProps = new HashSet(setters.keySet());
writeOnlyProps.removeAll(processedProps);
Iterator ss = writeOnlyProps.iterator();
while (ss.hasNext()) {
String name = (String) ss.next();
PropertyDescriptor setter = (PropertyDescriptor) setters.get(name);
props.add(setter);
}
return props;
}
}
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