se.altrusoft.docserv.models.DynamicModel.java Source code

Introduction

Here is the source code for se.altrusoft.docserv.models.DynamicModel.java

Source

/*
 * Copyright (c) 2013 Altrusoft AB.
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
package se.altrusoft.docserv.models;

import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import net.sf.cglib.beans.BeanGenerator;
import net.sf.cglib.core.NamingPolicy;
import net.sf.cglib.core.Predicate;

import org.apache.commons.beanutils.BeanUtils;

public class DynamicModel extends TemplateModel {

    public static TemplateModel getTemplateModel(String templateName, LinkedHashMap<String, Object> templateValues)
            throws Exception {
        Class<?> dynamicBeanClass = getDynamicBeanClass(templateName, templateValues);
        Object dynamicBeanObject = dynamicBeanClass.newInstance();
        BeanUtils.populate(dynamicBeanObject, templateValues);

        if (dynamicBeanObject instanceof TemplateModel) {
            return (TemplateModel) dynamicBeanObject;
        }

        throw new Exception("Unexpectly failed to generate DynamicBeanObject based on template values");
    }

    private static Class<?> getDynamicBeanClass(String templateName, LinkedHashMap<String, Object> model) {
        Map<String, Class<?>> classAttributes = new HashMap<String, Class<?>>();
        traverseStructure(model, classAttributes);
        // TODO: probably have different names for each usage of same template
        // (the first json-object might not be complete containing all possible
        // parameters)
        return createBeanClass(templateName, TemplateModel.class, classAttributes);
    }

    @SuppressWarnings("unchecked")
    private static void traverseStructure(Object node, Map<String, Class<?>> attributes) {
        if (node instanceof Map) {
            LinkedHashMap<String, Object> map = (LinkedHashMap<String, Object>) node;
            Set<Entry<String, Object>> entrySet = map.entrySet();
            Iterator<Entry<String, Object>> iterator = entrySet.iterator();
            while (iterator.hasNext()) {
                Entry<String, Object> entry = iterator.next();
                traverseStructure(entry, attributes);
            }
        } else if (node instanceof Entry) {
            Entry<String, Object> entry = (Entry<String, Object>) node;
            Object value = entry.getValue();
            if (value instanceof Map) {
                traverseStructure(value, attributes);
            } else {
                Class<?> attributeClass = value.getClass();
                String attributeName = entry.getKey();
                attributes.put(attributeName, attributeClass);
            }
        }
    }

    private static Class<?> createBeanClass(final String className, Class<TemplateModel> superClass,
            final Map<String, Class<?>> properties) {
        final BeanGenerator beanGenerator = new BeanGenerator();
        beanGenerator.setSuperclass(superClass);
        beanGenerator.setNamingPolicy(new NamingPolicy() {
            @Override
            public String getClassName(final String prefix, final String source, final Object key,
                    final Predicate names) {
                return className;
            }
        });
        BeanGenerator.addProperties(beanGenerator, properties);
        return (Class<?>) beanGenerator.createClass();
    }

    @Override
    public boolean isDynamic() {
        return true;
    }
}