| /** |
| * Copyright 2013 Florian Schmaus |
| * |
| * All rights reserved. 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 org.jivesoftware.smack.compression; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.zip.Deflater; |
| import java.util.zip.DeflaterOutputStream; |
| import java.util.zip.Inflater; |
| import java.util.zip.InflaterInputStream; |
| |
| /** |
| * This class provides XMPP "zlib" compression with the help of the Deflater class of the Java API. Note that the method |
| * needed is available since Java7, so it will only work with Java7 or higher (hence it's name). |
| * |
| * @author Florian Schmaus |
| * @see <a |
| * href="http://docs.oracle.com/javase/7/docs/api/java/util/zip/Deflater.html#deflate(byte[], int, int, int)">The |
| * required deflate() method</a> |
| * |
| */ |
| public class Java7ZlibInputOutputStream extends XMPPInputOutputStream { |
| private final static Method method; |
| private final static boolean supported; |
| private final static int compressionLevel = Deflater.DEFAULT_STRATEGY; |
| |
| static { |
| Method m = null; |
| try { |
| m = Deflater.class.getMethod("deflate", byte[].class, int.class, int.class, int.class); |
| } catch (SecurityException e) { |
| } catch (NoSuchMethodException e) { |
| } |
| method = m; |
| supported = (method != null); |
| } |
| |
| public Java7ZlibInputOutputStream() { |
| compressionMethod = "zlib"; |
| } |
| |
| @Override |
| public boolean isSupported() { |
| return supported; |
| } |
| |
| @Override |
| public InputStream getInputStream(InputStream inputStream) { |
| return new InflaterInputStream(inputStream, new Inflater(), 512) { |
| /** |
| * Provide a more InputStream compatible version. A return value of 1 means that it is likely to read one |
| * byte without blocking, 0 means that the system is known to block for more input. |
| * |
| * @return 0 if no data is available, 1 otherwise |
| * @throws IOException |
| */ |
| @Override |
| public int available() throws IOException { |
| /* |
| * aSmack related remark (where KXmlParser is used): |
| * This is one of the funny code blocks. InflaterInputStream.available violates the contract of |
| * InputStream.available, which breaks kXML2. |
| * |
| * I'm not sure who's to blame, oracle/sun for a broken api or the google guys for mixing a sun bug with |
| * a xml reader that can't handle it.... |
| * |
| * Anyway, this simple if breaks suns distorted reality, but helps to use the api as intended. |
| */ |
| if (inf.needsInput()) { |
| return 0; |
| } |
| return super.available(); |
| } |
| }; |
| } |
| |
| @Override |
| public OutputStream getOutputStream(OutputStream outputStream) { |
| return new DeflaterOutputStream(outputStream, new Deflater(compressionLevel)) { |
| public void flush() throws IOException { |
| if (!supported) { |
| super.flush(); |
| return; |
| } |
| int count = 0; |
| if (!def.needsInput()) { |
| do { |
| count = def.deflate(buf, 0, buf.length); |
| out.write(buf, 0, count); |
| } while (count > 0); |
| out.flush(); |
| } |
| try { |
| do { |
| count = (Integer) method.invoke(def, buf, 0, buf.length, 2); |
| out.write(buf, 0, count); |
| } while (count > 0); |
| } catch (IllegalArgumentException e) { |
| throw new IOException("Can't flush"); |
| } catch (IllegalAccessException e) { |
| throw new IOException("Can't flush"); |
| } catch (InvocationTargetException e) { |
| throw new IOException("Can't flush"); |
| } |
| super.flush(); |
| } |
| }; |
| } |
| |
| } |