Java tutorial
/** * Copyright 2013 OpenSocial Foundation * Copyright 2013 International Business Machines Corporation * * 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. * * Utility library for working with Activity Streams Actions * Requires underscorejs. * * @author James M Snell (jasnell@us.ibm.com) */ package com.ibm.common.activitystreams.legacy; import java.io.IOException; import java.io.InputStream; import java.io.ObjectStreamException; import java.io.OutputStream; import java.io.StringReader; import java.io.StringWriter; import com.google.common.hash.Hashing; import com.google.common.hash.HashingInputStream; import com.google.common.hash.HashingOutputStream; import com.google.common.io.BaseEncoding; import com.google.common.net.MediaType; import com.ibm.common.activitystreams.ASObject; /** * The legacy "binary" objectType. * * <pre> * InputStream in = ... * // will base64 encode, gzip compress and md5 sum the input data * // will also set the length property accordingly * Binary binary = * LegacyMakers.binary() * .gzipData(in) * .get(); * </pre> * * @author james * */ public final class Binary extends ASObject { public static final class Builder extends ASObject.AbstractBuilder<Binary, Builder> { Builder() { objectType("binary"); } /** * Set the input data without any compression. Will automatically * set calculate the md5 sum and length properties * @param in InputStream * @return Builder * @throws IOException */ public Builder data(InputStream in) throws IOException { return data(in, null); } /** * Set the input data with GZip compression. Will automatically * set calculate the md5 sum and length properties * @param in InputStream * @return Builder * @throws IOException */ public Builder gzipData(InputStream in) throws IOException { return data(in, Compression.GZipCompression); } /** * Set the input data with Deflate compression. Will automatically * set calculate the md5 sum and length properties * @param in InputStream * @return Builder * @throws IOException */ public Builder deflateData(InputStream in) throws IOException { return data(in, Compression.DeflateCompression); } /** * Set the input data the given Compression. Will automatically * set calculate the md5 sum and length properties * @param in InputStream * @return Builder * @throws IOException */ public Builder data(InputStream in, Compression<?, ?> compression) throws IOException { StringWriter writer = new StringWriter(); OutputStream out = BaseEncoding.base64Url().encodingStream(writer); if (compression != null) out = compression.compressor(out); HashingOutputStream hout = new HashingOutputStream(Hashing.md5(), out); byte[] buf = new byte[1024]; int r = -1; long size = 0; while ((r = in.read(buf)) > -1) { hout.write(buf, 0, r); size += r; } set("length", size); if (compression != null) { set("compression", compression.label()); compression.finish(out); } hout.close(); set("md5", hout.hash().toString()); return set("data", writer.toString()); } /** * Manually set the md5 properties (this is not recommended. calling the data * methods will automatically generate the md5 checksum for you) * * @param md5 String * @return Builder */ public Builder md5(String md5) { return set("md5", md5); } /** * Set the fileUrl property * @param fileUrl String * @return Builder */ public Builder fileUrl(String fileUrl) { return set("fileUrl", fileUrl); } /** * Set the MIME Media Type using the Legacy "mimeType" property name * rather than the AS 2.0 "mediaType" property name * @param mt MediaType * @return Builder */ @Override public Builder mediaType(MediaType mt) { return set("mimeType", mt); } /** * Get the built Binary object */ public Binary get() { return new Binary(this); } } private Binary(Builder builder) { super(builder); } /** * Get the fileUrl property * @return String */ public String fileUrl() { return getString("fileUrl"); } /** * Get the length property * @return long */ public long length() { return getLong("length"); } /** * Get the compression property value (typically "gzip" or "deflate") * @return String */ public String compression() { return getString("compression"); } /** * True if compression = gzip * @return boolean */ public boolean isGzip() { return "gzip".equalsIgnoreCase(compression()); } /** * True if compression = deflate * @return boolean */ public boolean isDeflate() { return "deflate".equalsIgnoreCase(compression()); } /** * Return the md5 checksum * @return String */ public String md5() { return getString("md5"); } /** * Return the literal string content of the data property. * This will be base64 encoded and optionally compressed * @return String */ public String data() { return getString("data"); } /** * Return an InputStream for reading the data. Will * decompress and base64 decode as necessary * @return InputStream * @throws IOException */ public InputStream read() throws IOException { Compression<?, ?> compression = isGzip() ? Compression.GZipCompression : isDeflate() ? Compression.DeflateCompression : null; return read(compression); } /** * Return an InputStream for reading the data * @param compression Compression * @return InputStream * @throws IOException */ public InputStream read(Compression<?, ?> compression) throws IOException { StringReader reader = new StringReader(data()); InputStream in = BaseEncoding.base64Url().decodingStream(reader); if (compression != null) in = compression.decompressor(in); if (has("md5")) in = new HashingInputStream(Hashing.md5(), in); return in; } /** * Return the MIME MediaType using the legacy "mimeType" property name * rather than the AS 2.0 "mediaType" name */ @Override public MediaType mediaType() { return this.<MediaType>get("mimeType"); } // Java Serialization Support Object writeReplace() throws java.io.ObjectStreamException { return new SerializedForm(this); } private static class SerializedForm extends AbstractSerializedForm<Binary> { private static final long serialVersionUID = -2060301713159936285L; protected SerializedForm(Binary obj) { super(obj); } Object readResolve() throws ObjectStreamException { return super.doReadResolve(); } protected Binary.Builder builder() { return new Builder(); } } }