org.directwebremoting.util.ClasspathScanner Maven / Gradle / Ivy

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DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boiler plate code between the web browser and your Java code.
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/*
 * Copyright 2005 Joe Walker
 *
 * 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 org.directwebremoting.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * ClasspathScanner enables you to find the set of classes that match some
 * package name. The search can be recursive.
 * @author Jose Noheda [jose.noheda at gmail dot com]
 * @author Joe Walker [joe at getahead dot ltd dot uk]
 */
public class ClasspathScanner
{

    /**
     * Attempt to find all classes in the VM
     */
    public ClasspathScanner()
    {
        this(null, true);
    }

    /**
     * Non recursively find classes within the given package
     * @param packageName package name specified with dot separators
     */
    public ClasspathScanner(String packageName)
    {
        this(packageName, false);
    }

    /**
     * Find classes within the given package (optionally recursively)
     * @param packageName package name specified with dot separator
     * @param recursive True to dig into sub-packages
     */
    public ClasspathScanner(String packageName, boolean recursive)
    {
        this.recursive = recursive;

        if (packageName == null)
        {
            packageName = "";
        }

        packageName = packageName.replace('.', '/');

        if (packageName.endsWith("*"))
        {
            packageName = packageName.substring(0, packageName.length() - 1);
        }

        if (packageName.endsWith("/"))
        {
            packageName = packageName.substring(0, packageName.length() - 1);
        }

        this.packageName = packageName;
    }

    /**
     * Get the list of classes available to the classloader
     */
    public Set getClasses()
    {
        Set classes = new HashSet();

        try
        {
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
            String match = packageName;
            if (match == "/")
            {
                match = "";
            }

            Enumeration resources = classLoader.getResources(match + "/");
            while (resources.hasMoreElements())
            {
                URL resource = resources.nextElement();
                String path = sanitizePath(resource.getFile());
                if ((path == null) || (path.trim().length() <= 0))
                {
                    continue;
                }
                if ("vfszip".equals(resource.getProtocol())) {
                    classes.addAll(getClassesFromVFS(path));
                } else if (isJARPath(path))
                {
                    classes.addAll(getClassesFromJAR(path));
                }
                else
                {
                    classes.addAll(getClassesFromDirectory(path));
                }
            }
        }
        catch (IOException ex)
        {
            log.warn("Failed to find any resources from classloader");
        }

        return classes;
    }

    /**
     * Is this path pointing at a JAR file?
     */
    protected boolean isJARPath(String path)
    {
        return (path.indexOf("!") > 0) & (path.indexOf(".jar") > 0);
    }

    /**
     * Extract the classes from a JAR file
     */
    protected Set getClassesFromJAR(String path) throws IOException
    {
        Set classes = new HashSet();
        String jarPath = path.substring(0, path.indexOf("!")).substring(path.indexOf(":") + 1);
        JarInputStream jarFile = new JarInputStream(new FileInputStream(jarPath));
        try
        {
            while (true)
            {
                JarEntry jarEntry = jarFile.getNextJarEntry();
                if (jarEntry == null)
                {
                    break;
                }
                addIfMatches(classes, jarEntry.getName());
            }
        }
        finally
        {
            if (null != jarFile)
            {
                jarFile.close();
            }
        }
        return classes;
    }

    /**
     * Extract the classes from a set of classes in the file system
     */
    protected Set getClassesFromDirectory(String path)
    {
        Set classes = new HashSet();
        File directory = new File(path);
        if (directory.exists())
        {
            for (String file : directory.list())
            {
                File f = new File(directory, file);
                if (f.isFile())
                {
                    addIfMatches(classes, path.substring(path.indexOf(packageName)) + file);
                }
                else if (recursive)
                {
                    classes.addAll(getClassesFromDirectory(path + file + "/"));
                }
            }
        }
        return classes;
    }

    /**
     * Extract the classes from a set of classes within a JBoss 5 vfszip protocol URL
     */
    protected Set getClassesFromVFS(String path) throws IOException
    {
        Set classes = new HashSet();
        Pattern vfsPattern = Pattern.compile("(.*\\.[wej]ar)(/.*)");
        Matcher vfsMatcher = vfsPattern.matcher(path);
        if (vfsMatcher.matches()) {
            JarInputStream jarFile = new JarInputStream(new FileInputStream(vfsMatcher.group(1)));
            try
            {
                Pattern vfsEntryPattern;
                if (recursive) {
                    vfsEntryPattern = Pattern.compile(".*(" + packageName + ".*/)([^/]+)\\.class");
                } else {
                    vfsEntryPattern = Pattern.compile(".*(" + packageName + "/)([^/]+)\\.class");
                }
                while (true)
                {
                    JarEntry jarEntry = jarFile.getNextJarEntry();
                    if (jarEntry == null)
                    {
                        break;
                    }
                    Matcher vfsEntryMatcher = vfsEntryPattern.matcher(jarEntry.getName());
                    if (vfsEntryMatcher.matches()) {
                        classes.add(vfsEntryMatcher.group(1).replace("/", ".") + vfsEntryMatcher.group(2));
                    }
                }
            }
            finally
            {
                if (null != jarFile)
                {
                    jarFile.close();
                }
            }
        }
        return classes;
    }

    /**
     * Check to see that the given file is a class in the right package and add
     * it to the given collection
     */
    protected void addIfMatches(Set classes, String className)
    {
        if ((className.startsWith(packageName)) && (className.endsWith(".class")))
        {
            boolean add = recursive ? true : className.substring(packageName.length() + 1).indexOf("/") < 0;
            if (add)
            {
                classes.add(className.substring(0, className.length() - 6).replace('/', '.'));
            }
        }
    }

    /**
     * Paths need cleaning up, especially in windows
     */
    protected String sanitizePath(String path)
    {
        String tmp = path;
        if (tmp.indexOf("%20") > 0)
        {
            // TODO: maybe we should do full URL decoding here?
            tmp = tmp.replaceAll("%20", " ");
        }

        if ((tmp.indexOf(":") >= 0) && (tmp.startsWith("/")))
        {
            // Remove leading / in URLs like /c:/...
            tmp = tmp.substring(1);
        }

        return tmp;
    }

    /**
     * The package name we are finding classes in
     */
    private final String packageName;

    /**
     * Are we digging recursively?
     */
    private final boolean recursive;

    /**
     * The log stream
     */
    private static final Log log = LogFactory.getLog(ClasspathScanner.class);
}