org.apache.struts.dispatcher.AbstractMethodResolver Maven / Gradle / Ivy
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*
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package org.apache.struts.dispatcher;
import org.apache.struts.chain.contexts.ActionContext;
import java.lang.reflect.Method;
/**
* This abstract class is the stock template for resolving methods for a
* {@link Dispatcher}. The implementation handles methods that accept no
* arguments or only an {@link ActionContext} instance:
*
* return_type execute()return_type execute(ActionContext context)
*
* @version $Rev$
* @since Struts 1.4
*/
public abstract class AbstractMethodResolver implements MethodResolver {
/**
* The argument listing for a method without arguments.
*
* @see #EMPTY_ARGUMENT_TYPES
*/
protected static final Object[] EMPTY_ARGUMENTS = new Object[] {};
/**
* The type listing used for a method without arguments.
*
* @see #EMPTY_ARGUMENTS
*/
protected static final Class[] EMPTY_ARGUMENT_TYPES = new Class[] {};
/**
* The argument listing for a method accepting the {@link ActionContext}.
*/
private static final Class[] ACTION_CONTEXT_ARGUMENT_TYPES = new Class[] { ActionContext.class };
public Object[] buildArguments(ActionContext context, Method method) {
Class[] parameterTypes = method.getParameterTypes();
switch (parameterTypes.length) {
case 0:
return EMPTY_ARGUMENTS;
case 1:
if (parameterTypes[0].isInstance(context)) {
return new Object[] { context };
}
return null;
default:
return null;
}
}
public Method resolveMethod(ActionContext context, String methodName) throws NoSuchMethodException {
Class actionClass = context.getAction().getClass();
// Does the method accept nothing?
try {
return actionClass.getMethod(methodName, EMPTY_ARGUMENT_TYPES);
} catch (NoSuchMethodException e) {
// continue
}
// Does the method accept the action context?
return actionClass.getMethod(methodName, ACTION_CONTEXT_ARGUMENT_TYPES);
}
}