Java tutorial
/** * Copyright (C) 2012-2015 the original author or authors. * * 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 ninja.uploads; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.nio.file.Files; import java.nio.file.StandardCopyOption; import ninja.utils.NinjaConstant; import ninja.utils.NinjaProperties; import org.apache.commons.fileupload.FileItemHeaders; import org.apache.commons.fileupload.FileItemStream; import com.google.inject.Inject; import com.google.inject.Singleton; /** * {@link FileItemProvider} that save uploaded files on disk, in a temporary folder. * The default folder location is specified by the system property "java.io.tmpdir", * and can be changed using "uploads.temp_folder" ninja property. * <br><br> * Temporary files are automatically deleted at the end or the request. * * @author Christian Bourgeois * */ @Singleton public class DiskFileItemProvider implements FileItemProvider { private File tmpFolder; @Inject public DiskFileItemProvider(NinjaProperties ninjaProperties) { String tempName = ninjaProperties.get(NinjaConstant.UPLOADS_TEMP_FOLDER); if (tempName == null) { tempName = System.getProperty("java.io.tmpdir"); } this.tmpFolder = new File(tempName); if (!tmpFolder.exists()) { tmpFolder.mkdirs(); } } @Override public FileItem create(FileItemStream item) { File tmpFile = null; // do copy try (InputStream is = item.openStream()) { tmpFile = File.createTempFile("nju", null, tmpFolder); Files.copy(is, tmpFile.toPath(), StandardCopyOption.REPLACE_EXISTING); } catch (IOException e) { throw new RuntimeException("Failed to create temporary uploaded file on disk", e); } // return final String name = item.getName(); final File file = tmpFile; final String contentType = item.getContentType(); final FileItemHeaders headers = item.getHeaders(); return new FileItem() { @Override public String getFileName() { return name; } @Override public InputStream getInputStream() { try { return new FileInputStream(file); } catch (FileNotFoundException e) { throw new RuntimeException("Failed to read temporary uploaded file from disk", e); } } @Override public File getFile() { return file; } @Override public String getContentType() { return contentType; } @Override public FileItemHeaders getHeaders() { return headers; } @Override public void cleanup() { // try to delete temporary file, silently fail on error try { file.delete(); } catch (Exception e) { } } }; } }