public Object get(Object key) {
String attributePath = (String) key;
if ("_className".equals(attributePath)) return className;
if ("_obj".equals(attributePath)) return obj;
if ("_querystr".equals(attributePath)) {
try {
Object id = ReflectionUtils.get(obj, "id");
return "?query=" + className + "&" + className + "[@id=" + id + "]";
} catch (Exception e) {
log.error("Error constructing URL", e);
return "#";
}
}
if ("displayMap".equals(attributePath)) {
return getDisplayMap();
}
return resolve(obj, attributePath);
}
/**
* Evaluates the specified path on the given object and returns the end point object in the path,
* if any. This function is called recursively for each segment of the path.
*
* @param object A Java bean with getters.
* @param path An object path as specified in the class docs.
* @return The end point object, or null.
*/
private Object resolve(Object object, String path) {
if (object == null) return null;
if (path == null) return object;
if ("class".equals(path)) {
String cn = object.getClass().getName();
return cn.substring(cn.lastIndexOf('.') + 1).split("\\$\\$")[0];
}
int d = path.indexOf('.');
String attr = (d < 0) ? path : path.substring(0, d);
String constraint = getConstraint(attr);
String constrainAttr = null;
String constrainValue = null;
int index = -1;
if (constraint != null) {
try {
index = Integer.parseInt(constraint);
} catch (NumberFormatException e) {
String[] cvs = constraint.split("=");
constrainAttr = cvs[0];
constrainValue = cvs[1];
}
attr = attr.substring(0, attr.indexOf('['));
}
Object nextObj;
try {
nextObj = ReflectionUtils.get(object, attr);
} catch (Exception e) {
log.error("Attribute error for " + path, e);
return "ERROR";
}
String nextPath = d < 0 ? null : path.substring(d + 1);
if (nextObj instanceof List) {
List nextList = (List) nextObj;
// just need one element from the list
if (index >= 0) {
try {
nextObj = nextList.get(index);
} catch (IndexOutOfBoundsException e) {
return "";
}
return resolve(nextObj, nextPath);
}
// aggregate all the resolved elements in the list
List resolved = new ArrayList();
for (Object e : nextList) {
// constrain by an attribute if one was provided
if (constrainAttr == null || resolve(e, constrainAttr).equals(constrainValue)) {
Object o = resolve(e, nextPath);
resolved.add(o);
}
}
return resolved;
} else {
return resolve(nextObj, nextPath);
}
}
