Java tutorial
/* * This library is part of OpenCms - * the Open Source Content Management System * * Copyright (c) Alkacon Software GmbH (http://www.alkacon.com) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * For further information about Alkacon Software GmbH, please see the * company website: http://www.alkacon.com * * For further information about OpenCms, please see the * project website: http://www.opencms.org * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package org.opencms.util; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.util.Date; import java.util.Hashtable; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; import org.apache.commons.codec.binary.Base64; /** * * Utilities to handle basic data types.<p> * * @since 6.5.6 */ public final class CmsDataTypeUtil { /** * Hides the public constructor.<p> */ private CmsDataTypeUtil() { // noop } /** * Returns the deserialized (if needed) object.<p> * * @param data the data to deserialize * @param type the data type * * @return the deserialized object * * @throws IOException if the inputstream fails * @throws ClassNotFoundException if the serialized object fails */ public static Object dataDeserialize(byte[] data, String type) throws IOException, ClassNotFoundException { // check the type of the stored data Class clazz = Class.forName(type); if (isParseable(clazz)) { // this is parseable data return parse(new String(data), clazz); } // this is a serialized object ByteArrayInputStream bin = new ByteArrayInputStream(data); ObjectInputStream oin = new ObjectInputStream(bin); return oin.readObject(); } /** * Returns a ready to export string representation of the given object.<p> * * For not parseable objects, base64 encoded string with the serialized object is generated.<p> * * @param data the object to export * * @return the string representation * * @throws IOException if something goes wrong */ public static String dataExport(Object data) throws IOException { if (CmsDataTypeUtil.isParseable(data.getClass())) { return CmsDataTypeUtil.format(data); } ByteArrayOutputStream bout = new ByteArrayOutputStream(); ObjectOutputStream oout = new ObjectOutputStream(bout); oout.writeObject(data); oout.close(); return new String(Base64.encodeBase64(bout.toByteArray())); } /** * Returns the import data object.<p> * * @param value the exported value * @param type the expected data type * * @return the import data object * * @throws ClassNotFoundException if something goes wrong * @throws IOException if something goes wrong */ public static Object dataImport(String value, String type) throws ClassNotFoundException, IOException { Class clazz = Class.forName(type); if (CmsDataTypeUtil.isParseable(clazz)) { return CmsDataTypeUtil.parse(value, clazz); } byte[] data = Base64.decodeBase64(value.getBytes()); return dataDeserialize(data, type); } /** * Serialize the given data.<p> * * @param data the data to serialize * * @return byte[] the serailized data * * @throws IOException if something goes wrong */ public static byte[] dataSerialize(Object data) throws IOException { if (isParseable(data.getClass())) { return format(data).getBytes(); } // serialize the data ByteArrayOutputStream bout = new ByteArrayOutputStream(); ObjectOutputStream oout = new ObjectOutputStream(bout); Object obj = data; if (data instanceof Map) { Hashtable ht = new Hashtable(); Iterator it = ((Map) data).entrySet().iterator(); while (it.hasNext()) { Map.Entry entry = (Entry) it.next(); if ((entry.getKey() != null) && (entry.getValue() != null)) { ht.put(entry.getKey(), entry.getValue()); } } obj = ht; } oout.writeObject(obj); oout.close(); return bout.toByteArray(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(boolean data) { return String.valueOf(data); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(byte data) { return new Byte(data).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(char data) { return new Character(data).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(Date data) { return new Long(data.getTime()).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(double data) { return new Double(data).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(float data) { return new Float(data).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(int data) { return new Integer(data).toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(long data) { return new Long(data).toString(); } /** * Formats the given data into a string value depending on the data type.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(Object data) { if (data == null) { return null; } Class clazz = data.getClass(); if (clazz.equals(Date.class)) { return format(((Date) data).getTime()); } return data.toString(); } /** * Formats the given data into a string value.<p> * * @param data the data to format * * @return a string representation of the given data */ public static String format(short data) { return new Short(data).toString(); } /** * Checks if the given class is representable as a string.<p> * * @param clazz the type to test * * @return if the given class is representable as a string */ public static boolean isParseable(Class clazz) { boolean parseable = false; parseable = parseable || (clazz.equals(byte.class)); parseable = parseable || (clazz.equals(Byte.class)); parseable = parseable || (clazz.equals(short.class)); parseable = parseable || (clazz.equals(Short.class)); parseable = parseable || (clazz.equals(int.class)); parseable = parseable || (clazz.equals(Integer.class)); parseable = parseable || (clazz.equals(long.class)); parseable = parseable || (clazz.equals(Long.class)); parseable = parseable || (clazz.equals(float.class)); parseable = parseable || (clazz.equals(Float.class)); parseable = parseable || (clazz.equals(double.class)); parseable = parseable || (clazz.equals(Double.class)); parseable = parseable || (clazz.equals(boolean.class)); parseable = parseable || (clazz.equals(Boolean.class)); parseable = parseable || (clazz.equals(char.class)); parseable = parseable || (clazz.equals(Character.class)); parseable = parseable || (clazz.equals(String.class)); parseable = parseable || (clazz.equals(Date.class)); parseable = parseable || (clazz.equals(CmsUUID.class)); return parseable; } /** * Converts Number to int.<p> * * @param n the number object * * @return Number.inValue(), 0 - if the parameter is null */ public static int numberToInt(Number n) { return (n == null ? 0 : n.intValue()); } /** * Returns an object of the given type (or a wrapper for base types) * with the value of the given data.<p> * * @param data the data to parse * @param clazz the data type * * @return the value of the given data */ public static Object parse(String data, Class clazz) { if (data == null) { return null; } if (clazz.equals(byte.class) || clazz.equals(Byte.class)) { return parseByte(data); } if (clazz.equals(short.class) || clazz.equals(Short.class)) { return parseShort(data); } if (clazz.equals(long.class) || clazz.equals(Long.class)) { return parseLong(data); } if (clazz.equals(int.class) || clazz.equals(Integer.class)) { return parseInt(data); } if (clazz.equals(float.class) || clazz.equals(Float.class)) { return parseFloat(data); } if (clazz.equals(double.class) || clazz.equals(Double.class)) { return parseDouble(data); } if (clazz.equals(boolean.class) || clazz.equals(Boolean.class)) { return parseBoolean(data); } if (clazz.equals(char.class) || clazz.equals(Character.class)) { return parseChar(data); } if (clazz.equals(CmsUUID.class)) { return parseUUID(data); } if (clazz.equals(Date.class)) { return parseDate(data); } return data; } /** * Parses the given data as a boolean.<p> * * @param data the data to parse * * @return the converted data value */ public static Boolean parseBoolean(String data) { return Boolean.valueOf(data); } /** * Parses the given data as a byte.<p> * * @param data the data to parse * * @return the converted data value */ public static Byte parseByte(String data) { return new Byte(data); } /** * Parses the given data as a char.<p> * * @param data the data to parse * * @return the converted data value */ public static Character parseChar(String data) { return new Character(data.charAt(0)); } /** * Parses the given data as a date.<p> * * @param data the data to parse * * @return the converted data value */ public static Date parseDate(String data) { return new Date(parseLong(data).longValue()); } /** * Parses the given data as a double.<p> * * @param data the data to parse * * @return the converted data value */ public static Double parseDouble(String data) { return new Double(data); } /** * Parses the given data as a float.<p> * * @param data the data to parse * * @return the converted data value */ public static Float parseFloat(String data) { return new Float(data); } /** * Parses the given data as an integer.<p> * * @param data the data to parse * * @return the converted data value */ public static Integer parseInt(String data) { return new Integer(data); } /** * Parses the given data as a long.<p> * * @param data the data to parse * * @return the converted data value */ public static Long parseLong(String data) { return new Long(data); } /** * Parses the given data as a short.<p> * * @param data the data to parse * * @return the converted data value */ public static Short parseShort(String data) { return new Short(data); } /** * Parses the given data as an uuid.<p> * * @param data the data to parse * * @return the converted data value */ public static CmsUUID parseUUID(String data) { return new CmsUUID(data); } }