Java tutorial
/* Copyright (c) 2001 - 2013 OpenPlans - www.openplans.org. All rights reserved. * This code is licensed under the GPL 2.0 license, available at the root * application directory. */ package org.geoserver.web.wicket; import java.io.File; import java.io.InputStream; import java.net.URI; import java.net.URISyntaxException; import java.net.URLConnection; import java.util.Collections; import org.apache.commons.io.IOUtils; import org.apache.wicket.validation.IValidatable; import org.apache.wicket.validation.validator.AbstractValidator; import org.apache.wicket.validation.validator.UrlValidator; import org.geotools.util.Converters; import org.vfny.geoserver.global.GeoserverDataDirectory; /** * Checks the specified file exists on the file system, including checks in the data directory */ @SuppressWarnings("serial") public class FileExistsValidator extends AbstractValidator { private UrlValidator delegate; /** * Checks the file exists on the local file system */ public FileExistsValidator() { this(true); } /** * If <code>allowRemoveUrl</code> is true this validator allows the file to be either * local (no URI scheme, or file URI scheme) or a remote * @param allowRemoteUrl */ public FileExistsValidator(boolean allowRemoteUrl) { if (allowRemoteUrl) { this.delegate = new UrlValidator(); } } @Override protected void onValidate(IValidatable validatable) { String uriSpec = Converters.convert(validatable.getValue(), String.class); // Make sure we are dealing with a local path try { URI uri = new URI(uriSpec); if (uri.getScheme() != null && !"file".equals(uri.getScheme())) { if (delegate != null) { delegate.validate(validatable); InputStream is = null; try { URLConnection connection = uri.toURL().openConnection(); connection.setConnectTimeout(10000); is = connection.getInputStream(); } catch (Exception e) { error(validatable, "FileExistsValidator.unreachable", Collections.singletonMap("file", uriSpec)); } finally { IOUtils.closeQuietly(is); } } return; } else { // ok, strip away the scheme and just get to the path String path = uri.getPath(); if (path != null && new File(path).exists()) { return; } } } catch (URISyntaxException e) { // may be a windows path, move on } // local to data dir? File relFile = GeoserverDataDirectory.findDataFile(uriSpec); if (relFile == null || !relFile.exists()) { error(validatable, "FileExistsValidator.fileNotFoundError", Collections.singletonMap("file", uriSpec)); } } }