com.googlecode.gwt.test.assertions.GwtInstance Maven / Gradle / Ivy
package com.googlecode.gwt.test.assertions;
import com.googlecode.gwt.test.finder.GwtFinder;
import static com.googlecode.gwt.test.finder.GwtFinder.object;
/**
* Wrapper arround a raw object retrieved via {@link GwtFinder#object(String...)}.
*
* @author Gael Lazzari
*/
public class GwtInstance {
static void validateNotNull(Class type) {
if (type == null)
throw new IllegalArgumentException("Expected type cannot be null");
}
private final String[] identifier;
private final Object instance;
/**
* Creates a new {@link GwtInstance}.
*
* @param identifier The targeted object's identifier.
*/
protected GwtInstance(String... identifier) {
this.identifier = identifier;
this.instance = object(identifier);
}
/**
* Cast the wrapped object to the specified class
*
* @param type The type to convert to.
* @return The casted object
* @throws NullPointerException if the wrapped object is null.
* @throws ClassCastException if the wrapped object cannot be cast to the supplied type.
*/
@SuppressWarnings("unchecked")
public T ofType(Class type) throws NullPointerException, ClassCastException {
validateNotNull(type);
if (instance == null) {
throw new NullPointerException("Object with identifier '" + identifierToString()
+ "' is null");
}
return (T) instance;
}
final Object getInstance() {
return instance;
}
private String identifierToString() {
StringBuilder sb = new StringBuilder();
for (String s : identifier) {
sb.append("'").append(s).append("', ");
}
return sb.substring(0, sb.length() - 2);
}
}