/**
* Reads an object from a {@link IMemento}. The memento's type (root) must equal the bean's {@link
* Root} annotation name attribute.
*/
static <T> T fromMemento(Class<T> clazz, IMemento memento) throws IOException {
try {
final StringWriter sw = new StringWriter();
final XMLMemento m = XMLMemento.createWriteRoot(memento.getType());
m.putMemento(memento);
m.save(sw);
return new Persister().read(clazz, new StringReader(sw.toString()));
} catch (Exception e) {
throw ExceptionUtils.wrapAs(IOException.class, e);
}
}
/**
* A shortcut for:
*
* <pre>
* fromMemento(clazz, memento.getChild(childName))
* </pre>
*
* verifying precondition that only one child of a given name exists.
*/
static <T> T fromMemento(Class<T> clazz, IMemento memento, String childName) throws IOException {
final IMemento[] children = memento.getChildren(childName);
if (children.length != 1) {
throw new IOException(
"Expected a single node named '"
+ childName
+ "' under memento '"
+ memento.getType()
+ "'.");
}
return fromMemento(clazz, children[0]);
}
/** Convert any {@link IMemento} to a string. */
public static String toString(IMemento memento) {
if (!(memento instanceof XMLMemento)) {
XMLMemento m = XMLMemento.createWriteRoot(memento.getType());
m.putMemento(memento);
memento = m;
}
try {
final StringWriter w = new StringWriter();
((XMLMemento) memento).save(w);
return w.toString();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/** Add a child node to a given memento, named after the object's {@link Root} annotation. */
public static void addChild(IMemento memento, Object object) throws IOException {
checkObject(object);
final IMemento child = toMemento(object);
memento.createChild(child.getType()).putMemento(child);
}