/**
* Copyright (C) 2012-2017 52°North Initiative for Geospatial Open Source
* Software GmbH
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* If the program is linked with libraries which are licensed under one of
* the following licenses, the combination of the program with the linked
* library is not considered a "derivative work" of the program:
*
* - Apache License, version 2.0
* - Apache Software License, version 1.0
* - GNU Lesser General Public License, version 3
* - Mozilla Public License, versions 1.0, 1.1 and 2.0
* - Common Development and Distribution License (CDDL), version 1.0
*
* Therefore the distribution of the program linked with libraries licensed
* under the aforementioned licenses, is permitted by the copyright holders
* if the distribution is compliant with both the GNU General Public
* License version 2 and the aforementioned licenses.
*
* This program 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 General
* Public License for more details.
*/
package org.n52.sos.util;
import java.math.BigDecimal;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;
import org.joda.time.DateTime;
import org.reflections.Reflections;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.collect.Sets;
/**
* Helper class for Java objects.
*
* @since 4.0.0
*
*/
public final class JavaHelper {
private static final Logger LOGGER = LoggerFactory.getLogger(JavaHelper.class);
/**
* hexadecimal values
*/
private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
'E', 'F' };
/**
* Message digest for generating single identifier
*/
private static MessageDigest messageDigest;
private static Reflections reflections;
private static Random random;
/**
* Instantiation of the message digest
*/
static {
try {
messageDigest = MessageDigest.getInstance("SHA1");
reflections = new Reflections("org.n52.sos");
random = new Random();
} catch (final NoSuchAlgorithmException nsae) {
LOGGER.error("Error while getting SHA-1 messagedigest!", nsae);
}
}
/**
* Generates a sensor id from description and current time as long.
*
* @param message
* sensor description
* @return generated sensor id as hex SHA-1.
*/
public static String generateID(final String message) {
final long autoGeneratredID = new DateTime().getMillis();
final String concate = random.nextDouble() + message + Long.toString(autoGeneratredID);
return bytesToHex(messageDigest.digest(concate.getBytes()));
}
/**
* Transforms byte to hex representation
*
* @param b
* bytes
* @return hex
*/
private static String bytesToHex(final byte[] b) {
final StringBuilder buf = new StringBuilder();
for (final byte element : b) {
buf.append(HEX_DIGITS[(element >> 4) & 0x0f]);
buf.append(HEX_DIGITS[element & 0x0f]);
}
return buf.toString();
}
public static void appendTextToStringBuilderWithLineBreak(final StringBuilder stringBuilder, final String message) {
if (stringBuilder != null && StringHelper.isNotEmpty(message)) {
stringBuilder.append(message);
stringBuilder.append(Constants.LINE_SEPARATOR_STRING);
}
}
/**
* return Object value as String
*
* @param object
* to get as String
* @return String value
*/
public static String asString(final Object object) {
if (object instanceof String) {
return (String) object;
} else if (object instanceof BigDecimal) {
final BigDecimal bdValue = (BigDecimal) object;
return Double.toString(bdValue.doubleValue());
} else if (object instanceof Double) {
return ((Double) object).toString();
} else if (object instanceof Integer) {
return ((Integer) object).toString();
}
// TODO why not object.toString()?
return Constants.EMPTY_STRING;
}
/**
* return Object value as Double
*
* @param object
* to get as Double
* @return Double value
*/
public static Double asDouble(final Object object) {
if (object instanceof String) {
return Double.parseDouble((String) object);
} else if (object instanceof BigDecimal) {
final BigDecimal bdValue = (BigDecimal) object;
return bdValue.doubleValue();
} else if (object instanceof Double) {
return (Double) object;
}
return new Double(Double.NaN);
}
/**
* return Object value as Integer
*
* @param object
* to get as Integer
* @return Integer value
*/
public static Integer asInteger(Object object) {
if (object == null) {
return null;
} else if (object instanceof Integer) {
return (Integer) object;
} else if (object instanceof String) {
return Integer.valueOf((String) object);
}
return null;
}
/**
* return Object value as Boolean
*
* @param object
* to get as Boolean
* @return Boolean value
*/
public static Boolean asBoolean(Object object) {
if (object == null) {
return null;
} else if (object instanceof Boolean) {
return (Boolean) object;
} else if (object instanceof String) {
return Boolean.valueOf((String) object);
}
return null;
}
public static <T> Set<Class<? extends T>> getSubclasses(Class<T> clazz) {
return reflections.getSubTypesOf(clazz);
}
public static Set<Integer> getIntegerSetFromString(String s) {
HashSet<Integer> set = Sets.newHashSet();
if (StringHelper.isNotEmpty(s)) {
Set<String> splitToSet = StringHelper.splitToSet(s, Constants.COMMA_STRING);
if (CollectionHelper.isNotEmpty(splitToSet)) {
for (String string : splitToSet) {
set.add(Integer.parseInt(string));
}
}
}
return set;
}
private JavaHelper() {
}
}