net.contextfw.web.application.internal.util.ClassScanner Maven / Gradle / Ivy

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package net.contextfw.web.application.internal.util;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import net.contextfw.web.application.WebApplicationException;

public class ClassScanner extends AbstractScanner {

    public static List> getClasses(String... packageNames) {
        ArrayList list = new ArrayList(packageNames.length);
        Collections.addAll(list, packageNames);
        return getClasses(list);
    }
    
    /**
     * Scans all classes accessible from the context class loader which belong to the given package and subpackages.
     *
     * @param packageName The base package
     * @return The classes
     * @throws ClassNotFoundException
     * @throws IOException
     */
    public static List> getClasses(Iterable packageNames) {
    
        ArrayList> classes = new ArrayList>();
        
        try {
            for (String packageName : packageNames) {
                List resourcePaths = new ArrayList();
                resourcePaths.add(packageName);
                List entries = findResourceEntries(resourcePaths);

                for (ResourceEntry entry: entries) {
                    
                    String fileName = entry.getPath();
                    if (fileName.endsWith(".class") && !fileName.contains("$")) {
                        Class _class;
                        String className = toClassName(fileName);
                        try {
                            _class = Class.forName(className);
                        } catch (ExceptionInInitializerError e) {
                            // happen, for example, in classes, which depend on 
                            // Spring to inject some beans, and which fail, 
                            // if dependency is not fulfilled
                            _class = Class.forName(className,
                                    false, Thread.currentThread().getContextClassLoader());
                        }
                        classes.add(_class);
                    }
                }
            }
        } catch (ClassNotFoundException e) {
            throw new WebApplicationException(e);
        }
        
        return classes;
    }

    private static String toClassName(String fileName) {
        return fileName.substring(0, fileName.length() - 6).replaceAll("/", "\\.");
    }
    
    /**
     * Recursive method used to find all classes in a given directory and subdirs.
     *
     * @param directory   The base directory
     * @param packageName The package name for classes found inside the base directory
     * @return The classes
     * @throws ClassNotFoundException
     */
    private static List> findClasses(String parent, File directory, String packageName) throws ClassNotFoundException 
    {
        List> classes = new ArrayList>();
        if (!directory.exists()) {
            return classes;
        }
        File[] files = directory.listFiles();
        for (File file : files) {
            
            String fileName = file.getName();
            if (file.isDirectory()) {
                assert !fileName.contains(".");
                classes.addAll(findClasses(parent+"/"+fileName, file, packageName + "." + fileName));
            } else if (fileName.endsWith(".class") && !fileName.contains("$")) {
                Class _class;
                try {
                    _class = Class.forName(packageName + '.' + fileName.substring(0, fileName.length() - 6));
                } catch (ExceptionInInitializerError e) {
                    // happen, for example, in classes, which depend on 
                    // Spring to inject some beans, and which fail, 
                    // if dependency is not fulfilled
                    _class = Class.forName(packageName + '.' + fileName.substring(0, fileName.length() - 6),
                            false, Thread.currentThread().getContextClassLoader());
                }
                classes.add(_class);
            }
        }
        return classes;
    }
}