com.threewks.thundr.introspection.ClassIntrospector.java Source code

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Here is the source code for com.threewks.thundr.introspection.ClassIntrospector.java

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/*
 * This file is a component of thundr, a software library from 3wks.
 * Read more: http://3wks.github.io/thundr/
 * Copyright (C) 2014 3wks, <thundr@3wks.com.au>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.threewks.thundr.introspection;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import javax.inject.Inject;

import org.apache.commons.lang3.ClassUtils;

import com.atomicleopard.expressive.EList;
import com.atomicleopard.expressive.ETransformer;
import com.atomicleopard.expressive.Expressive;
import com.atomicleopard.expressive.transform.CollectionTransformer;

import jodd.introspector.ClassDescriptor;
import jodd.util.ReflectUtil;

/**
 * Provides reflective information on a {@link Class}.
 *
 * @see TypeIntrospector
 */
public class ClassIntrospector {
    public static final boolean supportsInjection = TypeIntrospector.classExists("javax.inject.Inject");

    @SuppressWarnings({ "rawtypes" })
    public <T> List<Constructor<T>> listConstructors(Class<T> type) {
        ClassDescriptor classDescriptor = new ClassDescriptor(type, true);
        CollectionTransformer<Constructor, Constructor<T>> castAll = Expressive.Transformers
                .transformAllUsing(ClassIntrospector.<Constructor, Constructor<T>>castTransformer());
        List<Constructor<T>> ctors = castAll.from(classDescriptor.getAllCtors(true));
        Collections.sort(ctors, new Comparator<Constructor<T>>() {
            @Override
            public int compare(Constructor<T> o1, Constructor<T> o2) {
                Class<?>[] types1 = o1.getParameterTypes();
                Class<?>[] types2 = o2.getParameterTypes();
                int compare = new Integer(types1.length).compareTo(types2.length);
                if (compare == 0) {
                    // to keep the outcome consistent, we want to deterministically sort
                    for (int i = 0; compare == 0 && i < types1.length; i++) {
                        compare = types1[i].getName().compareTo(types2[i].getName());
                    }
                }
                return compare;
            }
        });
        return ctors;
    }

    public <T> List<Method> listSetters(Class<T> type) {
        Method[] methods = ReflectUtil.getSupportedMethods(type);
        List<Method> setters = new ArrayList<Method>();
        for (Method method : methods) {
            if (ReflectUtil.getBeanPropertySetterName(method) != null) {
                setters.add(method);
            }
        }
        return setters;
    }

    public <T> List<Field> listInjectionFields(Class<T> type) {
        List<Field> injectionFields = new ArrayList<Field>();
        if (supportsInjection) {
            Field[] fields = ReflectUtil.getSupportedFields(type);
            for (Field field : fields) {
                boolean shouldInject = field.getAnnotation(Inject.class) != null;
                if (shouldInject) {
                    injectionFields.add(field);
                }
            }
        }
        return injectionFields;
    }

    public List<Class<?>> listImplementedTypes(Class<?> type) {
        EList<Class<?>> types = Expressive.<Class<?>>list(type);
        types.addItems(ClassUtils.getAllSuperclasses(type));
        types.addItems(ClassUtils.getAllInterfaces(type));
        return types;
    }

    private static <A, B> ETransformer<A, B> castTransformer() {
        return new ETransformer<A, B>() {
            @SuppressWarnings("unchecked")
            @Override
            public B from(A from) {
                return (B) from;
            }
        };
    }
}