SectionsBootstrapper.java

package org.fenixedu.bennu.core.bootstrap;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

import org.fenixedu.bennu.core.bootstrap.annotations.Bootstrap;
import org.fenixedu.bennu.core.bootstrap.annotations.Field;

import pt.ist.fenixframework.Atomic;
import pt.ist.fenixframework.Atomic.TxMode;

import com.google.gson.JsonObject;

public class SectionsBootstrapper {

    /**
     * Invokes all the declared methods with a {@link Bootstrap} annotation.
     * 
     * @param json
     *            the json that for each declared {@link Field} maps its key on its value.
     * 
     * @throws Throwable
     *             If errors ocurred during the bootstrap
     */
    @Atomic(mode = TxMode.WRITE)
    public static void bootstrapAll(JsonObject json) throws Throwable {
        Class<?>[] sections = BootstrapperRegistry.getSections().toArray(new Class<?>[0]);
        Object superSection = SectionInvocationHandler.newInstance(json, sections);
        for (Method method : BootstrapperRegistry.getBootstrapMethods()) {
            Object[] args = new Object[method.getParameterTypes().length];
            Arrays.fill(args, superSection);
            try {
                List<BootstrapError> errors = invokeIt(method, args);
                if (!errors.isEmpty()) {
                    throw new BootstrapException(errors);
                }
            } catch (InvocationTargetException e) {
                throw e.getCause();
            }
        }
    }

    private static List<BootstrapError> invokeIt(Method method, Object[] args) throws Exception {
        List<BootstrapError> errors = new ArrayList<>();
        Object result = method.invoke(null, args);
        if (result != null) {
            if (Collection.class.isAssignableFrom(result.getClass())) {
                for (Object item : (Collection<?>) result) {
                    if (BootstrapError.class.isAssignableFrom(item.getClass())) {
                        errors.add((BootstrapError) item);
                    }
                }
            } else if (BootstrapError.class.isAssignableFrom(result.getClass())) {
                errors.add((BootstrapError) result);
            }
        }

        return errors;
    }

    /*
     * This exception is thrown to indicate the Fenix Framework that it should abort the transaction.
     */
    public static class BootstrapException extends Exception {

        private static final long serialVersionUID = -5494716182369251565L;
        private final List<BootstrapError> errors;

        public BootstrapException(List<BootstrapError> errors) {
            this.errors = errors;
        }

        public List<BootstrapError> getErrors() {
            return errors;
        }

    }

}