adammurdoch 2003/02/20 21:12:03
Modified: vfs/src/java/org/apache/commons/vfs/impl
StandardFileSystemManager.java
Added: vfs/src/java/org/apache/commons/vfs/impl providers.xml
Log:
- Load list of providers from a config file, rather than hard-coding them.
- Allow the ClassLoader to load providers from to be set.
- Better checking for provider dependencies.
Revision Changes Path
1.12 +164 -37
jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/impl/StandardFileSystemManager.java
Index: StandardFileSystemManager.java
===================================================================
RCS file:
/home/cvs/jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/impl/StandardFileSystemManager.java,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -r1.11 -r1.12
--- StandardFileSystemManager.java 20 Feb 2003 07:30:36 -0000 1.11
+++ StandardFileSystemManager.java 21 Feb 2003 05:12:03 -0000 1.12
@@ -55,20 +55,19 @@
*/
package org.apache.commons.vfs.impl;
+import java.net.URL;
+import java.util.ArrayList;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.provider.FileProvider;
import org.apache.commons.vfs.util.Messages;
+import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
/**
* A {@link org.apache.commons.vfs.FileSystemManager} that configures itself
- * to use the standard providers and components. To use this manager:
- *
- * <ul>
- * <li>Create an instance of this class.
- * <li>Set the logger using {@link #setLogger} (optional).
- * <li>Add custom providers and components.
- * <li>Configure the manager using {@link #init}.
- * </ul>
+ * from an XML configuration file.
*
* @author <a href="mailto:[EMAIL PROTECTED]";>Adam Murdoch</a>
* @version $Revision$ $Date$
@@ -76,6 +75,28 @@
public class StandardFileSystemManager
extends DefaultFileSystemManager
{
+ private static final String CONFIG_RESOURCE = "providers.xml";
+
+ private String configUri;
+ private ClassLoader classLoader;
+
+ /**
+ * Sets the configuration file for this manager.
+ */
+ public void setConfiguration( final String configUri )
+ {
+ this.configUri = configUri;
+ }
+
+ /**
+ * Sets the ClassLoader to use to load the providers. Default is to
+ * use the ClassLoader that loaded this class.
+ */
+ public void setClassLoader( final ClassLoader classLoader )
+ {
+ this.classLoader = classLoader;
+ }
+
/**
* Initializes this manager. Adds the providers and replicator.
*/
@@ -86,41 +107,154 @@
setReplicator( new PrivilegedFileReplicator( replicator ) );
setTemporaryFileStore( replicator );
- // Add the standard providers
- addProvider( "file",
"org.apache.commons.vfs.provider.local.DefaultLocalFileProvider" );
- addProvider( "zip", "org.apache.commons.vfs.provider.zip.ZipFileProvider" );
- addProvider( "jar", "org.apache.commons.vfs.provider.jar.JarFileProvider" );
- addProvider( "ftp", "org.apache.commons.vfs.provider.ftp.FtpFileProvider" );
- addProvider( "smb", "org.apache.commons.vfs.provider.smb.SmbFileProvider" );
- addProvider( "webdav",
"org.apache.commons.vfs.provider.webdav.WebdavFileProvider" );
- addProvider( "sftp",
"org.apache.commons.vfs.provider.sftp.SftpFileProvider" );
- addProvider( "tmp",
"org.apache.commons.vfs.provider.temp.TemporaryFileProvider" );
-
- // Add a default provider
- final FileProvider provider = createProvider(
"org.apache.commons.vfs.provider.url.UrlFileProvider" );
- if ( provider != null )
+ if ( classLoader == null )
{
- setDefaultProvider( provider );
+ // Use default classloader
+ classLoader = getClass().getClassLoader();
+ }
+ if ( configUri == null )
+ {
+ // Use default config
+ final URL url = getClass().getResource( CONFIG_RESOURCE );
+ if ( url == null )
+ {
+ throw new FileSystemException( "vfs.impl/find-config-file.error",
CONFIG_RESOURCE );
+ }
+ configUri = url.toExternalForm();
}
+ // Configure
+ configure( configUri );
+
+ // Initialise super-class
super.init();
}
/**
- * Adds a provider.
+ * Configures this manager from an XML configuration file.
+ */
+ private void configure( final String configUri ) throws FileSystemException
+ {
+ try
+ {
+ // Load up the config
+ // TODO - validate
+ final DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
+ factory.setIgnoringElementContentWhitespace( true );
+ factory.setIgnoringComments( true );
+ factory.setExpandEntityReferences( true );
+ final DocumentBuilder builder = factory.newDocumentBuilder();
+ final Element config = builder.parse( configUri ).getDocumentElement();
+
+ // Add the providers
+ final NodeList providers = config.getElementsByTagName( "provider" );
+ final int count = providers.getLength();
+ for ( int i = 0; i < count; i++ )
+ {
+ final Element provider = (Element)providers.item( i );
+ addProvider( provider, false );
+ }
+
+ // Add the default provider
+ final NodeList defProviders = config.getElementsByTagName(
"default-provider" );
+ if ( defProviders.getLength() > 0 )
+ {
+ final Element provider = (Element)defProviders.item( 0 );
+ addProvider( provider, true );
+ }
+ }
+ catch ( final Exception e )
+ {
+ throw new FileSystemException( "vfs.impl/load-config.error", configUri,
e );
+ }
+ }
+
+ /**
+ * Adds a provider from a provider definition.
*/
- private void addProvider( final String scheme,
- final String providerClassName )
+ private void addProvider( final Element providerDef, final boolean isDefault )
throws FileSystemException
{
- final FileProvider provider = createProvider( providerClassName );
- if ( provider != null )
+ final String classname = providerDef.getAttribute( "class-name" );
+
+ // Make sure all required classes are in classpath
+ final String[] requiredClasses = getRequiredClasses( providerDef );
+ for ( int i = 0; i < requiredClasses.length; i++ )
{
- addProvider( scheme, provider );
+ final String requiredClass = requiredClasses[ i ];
+ if ( !findClass( requiredClass ) )
+ {
+ final String msg = Messages.getString(
"vfs.impl/skipping-provider.warn",
+ new String[] { classname,
requiredClass } );
+ getLog().warn( msg );
+ return;
+ }
+ }
+
+ // Create and register the provider
+ final FileProvider provider = createProvider( classname );
+ final String[] schemas = getSchemas( providerDef );
+ if ( schemas.length > 0 )
+ {
+ addProvider( schemas, provider );
+ }
+
+ // Set as default, if required
+ if ( isDefault )
+ {
+ setDefaultProvider( provider );
+ }
+ }
+
+ /**
+ * Tests if a class is available.
+ */
+ private boolean findClass( final String className )
+ {
+ try
+ {
+ classLoader.loadClass( className );
+ return true;
+ }
+ catch ( final ClassNotFoundException e )
+ {
+ return false;
}
}
/**
+ * Extracts the required classes from a provider definition.
+ */
+ private String[] getRequiredClasses( final Element providerDef )
+ {
+ final ArrayList classes = new ArrayList();
+ final NodeList deps = providerDef.getElementsByTagName( "if-available" );
+ final int count = deps.getLength();
+ for ( int i = 0; i < count; i++ )
+ {
+ final Element dep = (Element)deps.item( i );
+ classes.add( dep.getAttribute( "class-name" ) );
+ }
+ return (String[])classes.toArray( new String[ classes.size() ] );
+ }
+
+ /**
+ * Extracts the schema names from a provider definition.
+ */
+ private String[] getSchemas( final Element provider )
+ {
+ final ArrayList schemas = new ArrayList();
+ final NodeList schemaElements = provider.getElementsByTagName( "scheme" );
+ final int count = schemaElements.getLength();
+ for ( int i = 0; i < count; i++ )
+ {
+ final Element scheme = (Element)schemaElements.item( i );
+ schemas.add( scheme.getAttribute( "name" ) );
+ }
+ return (String[])schemas.toArray( new String[ schemas.size() ] );
+ }
+
+ /**
* Creates a provider.
*/
private FileProvider createProvider( final String providerClassName )
@@ -128,15 +262,8 @@
{
try
{
- final Class providerClass = Class.forName( providerClassName );
+ final Class providerClass = classLoader.loadClass( providerClassName );
return (FileProvider)providerClass.newInstance();
- }
- catch ( final ClassNotFoundException e )
- {
- // Ignore
- final String message = Messages.getString(
"vfs.impl/create-provider.warn", providerClassName );
- getLog().warn( message, e );
- return null;
}
catch ( final Exception e )
{
1.1
jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/impl/providers.xml
Index: providers.xml
===================================================================
<providers>
<default-provider
class-name="org.apache.commons.vfs.provider.url.UrlFileProvider"/>
<provider
class-name="org.apache.commons.vfs.provider.local.DefaultLocalFileProvider">
<scheme name="file"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.zip.ZipFileProvider">
<scheme name="zip"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.jar.JarFileProvider">
<scheme name="jar"/>
</provider>
<provider
class-name="org.apache.commons.vfs.provider.temp.TemporaryFileProvider">
<scheme name="tmp"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.ftp.FtpFileProvider">
<scheme name="ftp"/>
<if-available class-name="org.apache.commons.net.ftp.FTPFile"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.smb.SmbFileProvider">
<scheme name="smb"/>
<if-available class-name="jcifs.smb.SmbFile"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.webdav.WebdavFileProvider">
<scheme name="webdav"/>
<if-available class-name="org.apache.webdav.lib.WebdavResource"/>
</provider>
<provider class-name="org.apache.commons.vfs.provider.sftp.SftpFileProvider">
<scheme name="sftp"/>
<if-available class-name="com.jcraft.jsch.JSch"/>
</provider>
</providers>
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