Java tutorial
package edu.virginia.jtd5qe.twitter; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; public class ObjectSerializer { private static final Log log = LogFactory.getLog(ObjectSerializer.class); public static String serialize(Serializable obj) throws IOException { if (obj == null) return ""; try { ByteArrayOutputStream serialObj = new ByteArrayOutputStream(); ObjectOutputStream objStream = new ObjectOutputStream(serialObj); objStream.writeObject(obj); objStream.close(); return encodeBytes(serialObj.toByteArray()); } catch (Exception e) { throw WrappedIOException.wrap("Serialization error: " + e.getMessage(), e); } } public static Object deserialize(String str) throws IOException { if (str == null || str.length() == 0) return null; try { ByteArrayInputStream serialObj = new ByteArrayInputStream(decodeBytes(str)); ObjectInputStream objStream = new ObjectInputStream(serialObj); return objStream.readObject(); } catch (Exception e) { throw WrappedIOException.wrap("Deserialization error: " + e.getMessage(), e); } } public static String encodeBytes(byte[] bytes) { StringBuffer strBuf = new StringBuffer(); for (int i = 0; i < bytes.length; i++) { strBuf.append((char) (((bytes[i] >> 4) & 0xF) + ((int) 'a'))); strBuf.append((char) (((bytes[i]) & 0xF) + ((int) 'a'))); } return strBuf.toString(); } public static byte[] decodeBytes(String str) { byte[] bytes = new byte[str.length() / 2]; for (int i = 0; i < str.length(); i += 2) { char c = str.charAt(i); bytes[i / 2] = (byte) ((c - 'a') << 4); c = str.charAt(i + 1); bytes[i / 2] += (c - 'a'); } return bytes; } }