Java tutorial
/* * (C) Copyright 2006-2014 Nuxeo SA (http://nuxeo.com/) and others. * * 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. * * Contributors: * Nuxeo - initial API and implementation * */ package org.nuxeo.ecm.core.api; import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.OutputStream; import java.io.Serializable; import org.apache.commons.io.IOUtils; import org.nuxeo.runtime.api.Framework; /** * A serializable input stream. * <p> * Note: The stream is closed after the object is serialized. * * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a> */ public class SerializableInputStream extends InputStream implements Serializable { public static final int IN_MEM_LIMIT = 1024 * 64; private static final long serialVersionUID = -2816387281878881614L; private transient File file; private transient InputStream in; public SerializableInputStream(InputStream in) { this.in = in; } public SerializableInputStream(byte[] content) { in = new ByteArrayInputStream(content); } public SerializableInputStream(String content) { this(content.getBytes()); } @Override public int available() throws IOException { return in.available(); } @Override public void close() throws IOException { in.close(); } @Override public synchronized void mark(int readlimit) { in.mark(readlimit); } @Override public boolean markSupported() { return in.markSupported(); } @Override public int read() throws IOException { return in.read(); } @Override public int read(byte[] b, int off, int len) throws IOException { return in.read(b, off, len); } @Override public int read(byte[] b) throws IOException { return in.read(b); } @Override public synchronized void reset() throws IOException { in.reset(); } public File getTempFile() { return file; } public InputStream reopen() throws IOException { if (!canReopen()) { throw new IOException("Cannot reopen non persistent stream"); } return new BufferedInputStream(new FileInputStream(file)); } public boolean canReopen() { return file != null && file.isFile(); } @Override public long skip(long n) throws IOException { return in.skip(n); } private void readObject(ObjectInputStream in) throws ClassNotFoundException, IOException { // always perform the default de-serialization first in.defaultReadObject(); // create a temp file where we will put the blob content file = Framework.createTempFile("SerializableIS-", ".tmp"); Framework.trackFile(file, file); OutputStream out = null; try { out = new FileOutputStream(file); byte[] buffer = new byte[IN_MEM_LIMIT]; int read; int bytes = in.readInt(); while (bytes > -1 && (read = in.read(buffer, 0, bytes)) != -1) { out.write(buffer, 0, read); bytes -= read; if (bytes == 0) { bytes = in.readInt(); } } } finally { if (out != null) { out.close(); } if (file.isFile()) { this.in = new BufferedInputStream(new FileInputStream(file)); } } } private void writeObject(ObjectOutputStream out) throws IOException { out.defaultWriteObject(); // write content if (in == null) { return; } try { int read; byte[] buf = new byte[IN_MEM_LIMIT]; while ((read = in.read(buf)) != -1) { // next follows a chunk of 'read' bytes out.writeInt(read); out.write(buf, 0, read); } out.writeInt(-1); // EOF } finally { if (in != null) { in.close(); } } } @Override protected void finalize() throws Throwable { IOUtils.closeQuietly(in); if (file != null) { file.delete(); } super.finalize(); } }