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ClassLoaderFactory.javaAPI DocApache Tomcat 6.0.1411419Fri Jul 20 04:20:32 BST 2007org.apache.catalina.startup

ClassLoaderFactory

public final class ClassLoaderFactory extends Object

Utility class for building class loaders for Catalina. The factory method requires the following parameters in order to build a new class loader (with suitable defaults in all cases):

  • A set of directories containing unpacked classes (and resources) that should be included in the class loader's repositories.
  • A set of directories containing classes and resources in JAR files. Each readable JAR file discovered in these directories will be added to the class loader's repositories.
  • ClassLoader instance that should become the parent of the new class loader.
author
Craig R. McClanahan
version
$Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $

Fields Summary
private static org.apache.juli.logging.Log
log
protected static final Integer
IS_DIR
protected static final Integer
IS_JAR
protected static final Integer
IS_GLOB
protected static final Integer
IS_URL
Constructors Summary
Methods Summary
public static java.lang.ClassLoadercreateClassLoader(java.io.File[] unpacked, java.io.File[] packed, java.lang.ClassLoader parent)
Create and return a new class loader, based on the configuration defaults and the specified directory paths:

param
unpacked Array of pathnames to unpacked directories that should be added to the repositories of the class loader, or null for no unpacked directories to be considered
param
packed Array of pathnames to directories containing JAR files that should be added to the repositories of the class loader, or null for no directories of JAR files to be considered
param
parent Parent class loader for the new class loader, or null for the system class loader.
exception
Exception if an error occurs constructing the class loader


    // --------------------------------------------------------- Public Methods


                                                                                                                      
        
                                                 
                                                 
          
        return createClassLoader(unpacked, packed, null, parent);
public static java.lang.ClassLoadercreateClassLoader(java.io.File[] unpacked, java.io.File[] packed, java.net.URL[] urls, java.lang.ClassLoader parent)
Create and return a new class loader, based on the configuration defaults and the specified directory paths:

param
unpacked Array of pathnames to unpacked directories that should be added to the repositories of the class loader, or null for no unpacked directories to be considered
param
packed Array of pathnames to directories containing JAR files that should be added to the repositories of the class loader, or null for no directories of JAR files to be considered
param
urls Array of URLs to remote repositories, designing either JAR resources or uncompressed directories that should be added to the repositories of the class loader, or null for no directories of JAR files to be considered
param
parent Parent class loader for the new class loader, or null for the system class loader.
exception
Exception if an error occurs constructing the class loader


        if (log.isDebugEnabled())
            log.debug("Creating new class loader");

        // Construct the "class path" for this class loader
        ArrayList list = new ArrayList();

        // Add unpacked directories
        if (unpacked != null) {
            for (int i = 0; i < unpacked.length; i++)  {
                File file = unpacked[i];
                if (!file.exists() || !file.canRead())
                    continue;
                file = new File(file.getCanonicalPath() + File.separator);
                URL url = file.toURL();
                if (log.isDebugEnabled())
                    log.debug("  Including directory " + url);
                list.add(url);
            }
        }

        // Add packed directory JAR files
        if (packed != null) {
            for (int i = 0; i < packed.length; i++) {
                File directory = packed[i];
                if (!directory.isDirectory() || !directory.exists() ||
                    !directory.canRead())
                    continue;
                String filenames[] = directory.list();
                for (int j = 0; j < filenames.length; j++) {
                    String filename = filenames[j].toLowerCase();
                    if (!filename.endsWith(".jar"))
                        continue;
                    File file = new File(directory, filenames[j]);
                    if (log.isDebugEnabled())
                        log.debug("  Including jar file " + file.getAbsolutePath());
                    URL url = file.toURL();
                    list.add(url);
                }
            }
        }

        // Construct the class loader itself
        URL[] array = (URL[]) list.toArray(new URL[list.size()]);
        StandardClassLoader classLoader = null;
        if (parent == null)
            classLoader = new StandardClassLoader(array);
        else
            classLoader = new StandardClassLoader(array, parent);
        return (classLoader);
public static java.lang.ClassLoadercreateClassLoader(java.lang.String[] locations, java.lang.Integer[] types, java.lang.ClassLoader parent)
Create and return a new class loader, based on the configuration defaults and the specified directory paths:

param
locations Array of strings containing class directories, jar files, jar directories or URLS that should be added to the repositories of the class loader. The type is given by the member of param types.
param
types Array of types for the members of param locations. Possible values are IS_DIR (class directory), IS_JAR (single jar file), IS_GLOB (directory of jar files) and IS_URL (URL).
param
parent Parent class loader for the new class loader, or null for the system class loader.
exception
Exception if an error occurs constructing the class loader


        if (log.isDebugEnabled())
            log.debug("Creating new class loader");

        // Construct the "class path" for this class loader
        ArrayList list = new ArrayList();

        if (locations != null && types != null && locations.length == types.length) {
            for (int i = 0; i < locations.length; i++)  {
                String location = locations[i];
                if ( types[i] == IS_URL ) {
                    URL url = new URL(location);
                    if (log.isDebugEnabled())
                        log.debug("  Including URL " + url);
                    list.add(url);
                } else if ( types[i] == IS_DIR ) {
                    File directory = new File(location);
                    directory = new File(directory.getCanonicalPath());
                    if (!directory.exists() || !directory.isDirectory() ||
                        !directory.canRead())
                         continue;
                    URL url = directory.toURL();
                    if (log.isDebugEnabled())
                        log.debug("  Including directory " + url);
                    list.add(url);
                } else if ( types[i] == IS_JAR ) {
                    File file=new File(location);
                    file = new File(file.getCanonicalPath());
                    if (!file.exists() || !file.canRead())
                        continue;
                    URL url = file.toURL();
                    if (log.isDebugEnabled())
                        log.debug("  Including jar file " + url);
                    list.add(url);
                } else if ( types[i] == IS_GLOB ) {
                    File directory=new File(location);
                    if (!directory.exists() || !directory.isDirectory() ||
                        !directory.canRead())
                        continue;
                    if (log.isDebugEnabled())
                        log.debug("  Including directory glob "
                            + directory.getAbsolutePath());
                    String filenames[] = directory.list();
                    for (int j = 0; j < filenames.length; j++) {
                        String filename = filenames[j].toLowerCase();
                        if (!filename.endsWith(".jar"))
                            continue;
                        File file = new File(directory, filenames[j]);
                        file = new File(file.getCanonicalPath());
                        if (!file.exists() || !file.canRead())
                            continue;
                        if (log.isDebugEnabled())
                            log.debug("    Including glob jar file "
                                + file.getAbsolutePath());
                        URL url = file.toURL();
                        list.add(url);
                    }
                }
            }
        }

        // Construct the class loader itself
        URL[] array = (URL[]) list.toArray(new URL[list.size()]);
        if (log.isDebugEnabled())
            for (int i = 0; i < array.length; i++) {
                log.debug("  location " + i + " is " + array[i]);
            }
        StandardClassLoader classLoader = null;
        if (parent == null)
            classLoader = new StandardClassLoader(array);
        else
            classLoader = new StandardClassLoader(array, parent);
        return (classLoader);