ClassMemberSorter.java

/*
 * Copyright 2008 the original author or authors.
 *
 * 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 jdave.runner;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
 * Provides lists of class members (methods and inner classes) in the same
 * order as they have been declared in the source code. Requires that the
 * classes have been compiled with debug information (line numbers) included
 * in the bytecode and that the methods have a body (not native nor abstract).
 * 
 * @author Esko Luontola
 * @since 4.1.2008
 */
public final class ClassMemberSorter {
    private ClassMemberSorter() {
    }

    /**
     * @return the same as {@link Class#getClasses()} but in the same order as
     *         declared in the source code.
     */
    public static Class<?>[] getClasses(Class<?> declaringClass) {
        List<Class<?>> allDeclaredClasses = new ArrayList<Class<?>>();
        for (Class<?> clazz : inheritanceHierarchyOf(declaringClass)) {
            Class<?>[] classes = contextClassesDeclaredIn(clazz);
            Arrays.sort(classes, new ClassLineNumberComparator());
            allDeclaredClasses.addAll(Arrays.asList(classes));
        }
        return allDeclaredClasses.toArray(new Class[allDeclaredClasses.size()]);
    }

    private static Class<?>[] contextClassesDeclaredIn(Class<?> clazz) {
        return clazz.getDeclaredClasses();
    }

    private static List<Class<?>> inheritanceHierarchyOf(Class<?> declaringClass) {
        List<Class<?>> hierarchy = new ArrayList<Class<?>>();
        Class<?> root = declaringClass;
        do {
            hierarchy.add(root);
            root = root.getSuperclass();
        } while (root != null && !root.equals(Object.class));
        Collections.reverse(hierarchy);
        return hierarchy;
    }

    /**
     * @return the same as {@link Class#getMethods()} but in the same order as
     *         declared in the source code.
     */
    public static Method[] getMethods(Class<?> clazz) {
        Method[] methods = clazz.getMethods();
        Arrays.sort(methods, new MethodLineNumberComparator());
        return methods;
    }
}