Java tutorial
/* * Copyright (c) 2015 www.see-r.com * All rights reserved * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.seer.datacruncher.utils.generic; import com.seer.datacruncher.constants.ApplicationConfigType; import com.seer.datacruncher.constants.FileInfo; import com.seer.datacruncher.eventtrigger.DynamicClassLoader; import com.seer.datacruncher.jpa.dao.DaoSet; import com.seer.datacruncher.jpa.entity.ApplicationConfigEntity; import com.seer.datacruncher.spring.AppContext; import org.apache.commons.io.FileUtils; import org.apache.commons.lang.ArrayUtils; import org.apache.commons.lang.StringUtils; import org.json.JSONException; import org.json.JSONObject; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.context.ApplicationContext; import org.springframework.core.io.Resource; import org.springframework.ui.velocity.VelocityEngineUtils; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; import javax.persistence.EntityManager; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBElement; import javax.xml.bind.JAXBException; import javax.xml.bind.Unmarshaller; import javax.xml.bind.annotation.XmlAttribute; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlElementRef; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.xpath.*; import java.io.*; import java.lang.reflect.Field; import java.util.*; import java.util.zip.GZIPInputStream; import java.util.zip.GZIPOutputStream; public class CommonUtils implements DaoSet { private static DocumentBuilderFactory docFactory; private static DocumentBuilder docBuilder; private static XPathFactory xpathFactory; private static XPath xpathInstance; static { try { docFactory = DocumentBuilderFactory.newInstance(); docBuilder = docFactory.newDocumentBuilder(); xpathFactory = XPathFactory.newInstance(); xpathInstance = xpathFactory.newXPath(); } catch (ParserConfigurationException e) { org.apache.log4j.Logger.getLogger(CommonUtils.class) .error("CommonUtils :: DocumentBuilderFactory init exception", e); } } private CommonUtils() { } /** * MongoDB support is only inside EE module for Datastream entity. * * @return 'true' if MongoDB support exists and is checked in the form, 'false' otherwise */ public static synchronized boolean isMongoDB() { return getMongoChecked(); } //TODO: get the value from the checkbox private static boolean getMongoChecked() { return false; } /** * Checks whether current application contains a module * * @return 'true' if module exists */ public static synchronized boolean isModule() { boolean result = true; try { AppContext.getApplicationContext().getBean("isModule"); } catch (NoSuchBeanDefinitionException e) { result = false; } return result; } /** * Represents exception stack trace as string. * * @param e - Exception * @return exception stack trace as string */ public static String getExceptionAsString(Exception e) { StringWriter sw = new StringWriter(); e.printStackTrace(new PrintWriter(sw)); return sw.toString(); } /** * Gets velocity template file name by its short name. * * @param templateBaseName * @return */ private static String getVelocityTemplateName(String templateBaseName) { StringBuilder templatePath = new StringBuilder(); templatePath.append(templateBaseName); templatePath.append("_").append(Locale.getDefault().getLanguage()); templatePath.append(".vm"); return templatePath.toString(); } /** * Merge velocity template for email. * * @param velocityEngine * @param mailTemplate * @param model * @return merged string */ public static String mergeVelocityTemplateForEmail(org.apache.velocity.app.VelocityEngine velocityEngine, String mailTemplate, Map<String, String> model) { return VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, CommonUtils.getVelocityTemplateName(mailTemplate), "UTF-8", model); } public static File getResourceFile(String path) throws IOException { ApplicationContext context = AppContext.getApplicationContext(); Resource r = context.getResource(path); if (r.exists()) { return r.getFile(); } else { return new File(AppContext.getApplicationContext().getResource("/").getFile().getAbsolutePath() + path); } } /** * Checks whether current persistence unit is SQL SERVER (MS SQL). * * @param em * @return */ public synchronized static boolean isMsSql(EntityManager em) { return em == null ? false : em.getEntityManagerFactory() == null ? false : em.getEntityManagerFactory().getProperties() .get("hibernate.connection.driver_class") == null ? false : !em.getEntityManagerFactory().getProperties() .get("hibernate.connection.driver_class") .equals("net.sourceforge.jtds.jdbc.Driver") ? false : true; } /** * Checks whether current string is JSON. * * @param test * @return */ public synchronized static boolean isJSON(String test) { boolean valid = false; try { new JSONObject(test); valid = true; } catch (JSONException ex) { valid = false; } return valid; } /** * GZIP encode. * * @param str * @return * @throws IOException */ public synchronized static byte[] gzipEncode(String str) throws IOException { if (str == null || str.length() == 0) { return null; } ByteArrayOutputStream obj = new ByteArrayOutputStream(); GZIPOutputStream gzip = new GZIPOutputStream(obj); gzip.write(str.getBytes("UTF-8")); gzip.close(); return obj.toByteArray(); } /** * GZIP decode. * * @param bytes * @return * @throws IOException */ public static String gzipDecode(byte[] bytes) throws IOException { GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(bytes)); BufferedReader bf = new BufferedReader(new InputStreamReader(gis, "UTF-8")); String outStr = ""; String line; while ((line = bf.readLine()) != null) { outStr += line; } return outStr; } /** * Splits <tt>str</tt> around matches of the delimiter character. * * @param str * the string to split * * @param delimiter * the delimiting field string * * @param chrDelim * the delimiting character * * @return the array of strings computed by splitting string * around matches of the delimiter character. * **/ public static String[] fieldSplit(String str, String delimiter, char chrDelim) { if ((str.indexOf(chrDelim, 0)) < 0) { return StringUtils.splitPreserveAllTokens(str, delimiter); } else { ArrayList<String> list = new ArrayList<String>(); String record; List<String> streamsList = Arrays.asList(StringUtils.splitPreserveAllTokens(str, delimiter)); int fEnd; for (int i = 0; i < streamsList.size(); i++) { record = streamsList.get(i); if ((record.indexOf(chrDelim, 0)) < 0) { list.add(record); } else { if (record.startsWith(chrDelim + "")) { // check in start field fEnd = record.indexOf(chrDelim, 1); // find end if (fEnd < 0) { //not found if ((i + 1) < streamsList.size()) { streamsList.set(i + 1, record + delimiter + streamsList.get(i + 1)); } else { list.add(record); } } else { list.add(record); } } } } int resultSize = list.size(); String[] result = new String[resultSize]; return list.subList(0, resultSize).toArray(result); } } /** * Splits <tt>str</tt> around matches of the newline character. * * @param str * the string to split * * @param delimiter * the delimiting field string * * @param chrDelim * the delimiting character * * @return the array of strings computed by splitting string * around matches of the newline character. * **/ public static String[] lineSplit(String str, String delimiter, char chrDelim) { String linedelimiter = "\n"; String spltdelim = "\\"; if ((str.indexOf(chrDelim, 0)) < 0) { return str.split(spltdelim + linedelimiter); } else { ArrayList<String> list = new ArrayList<String>(); String record; List<String> streamsList = Arrays.asList(str.split(spltdelim + linedelimiter)); int fStart; int fEnd; boolean checkfields = true; for (int i = 0; i < streamsList.size(); i++) { record = streamsList.get(i); if ((record.indexOf(chrDelim, 0)) < 0) { list.add(record); } else { if (record.startsWith(chrDelim + "")) { // check in first field fEnd = record.indexOf(chrDelim + delimiter, 1); // find end if (fEnd < 0) { //not found if ((i + 1) < streamsList.size()) { streamsList.set(i + 1, record + linedelimiter + streamsList.get(i + 1)); } else { list.add(record); } checkfields = false; } else { checkfields = true; } } if (checkfields) { fStart = record.indexOf(delimiter + chrDelim, 1); while (fStart < record.length()) { if (fStart > 0) { fEnd = record.indexOf(chrDelim + delimiter, fStart); if (fEnd > 0) { fStart = record.indexOf(delimiter + chrDelim, fEnd); if (fStart < 0) { list.add(record); fStart = record.length(); } } else { fEnd = record.indexOf(chrDelim, fStart + 2); if (fEnd < 0) { if ((i + 1) < streamsList.size()) { streamsList.set(i + 1, record + linedelimiter + streamsList.get(i + 1)); } else { list.add(record); } } else { if (record.charAt(record.length() - 1) == chrDelim) { //last field list.add(record); } else { if ((i + 1) < streamsList.size()) { streamsList.set(i + 1, record + linedelimiter + streamsList.get(i + 1)); } else { list.add(record); } } } fStart = record.length(); } } else { fStart = record.length(); } } } } } int resultSize = list.size(); String[] result = new String[resultSize]; return list.subList(0, resultSize).toArray(result); } } /** * Method parse the schema file and identify the xpath expression for nodes that have annotation value * annotation could be @spellchaeck , @partitaiva, @codicefiscale, etc. * @param xmlSchema * @param annotation * @throws javax.xml.parsers.ParserConfigurationException * @throws org.xml.sax.SAXException * @throws IOException * @throws javax.xml.xpath.XPathExpressionException */ public static Set<String> parseSchemaAndGetXPathSetForAnnotation(ByteArrayInputStream xmlSchema, String annotation) throws ParserConfigurationException, SAXException, IOException, XPathExpressionException { Document doc = docBuilder.parse(xmlSchema); XPathExpression expr = xpathInstance.compile("//annotation/appinfo/text()"); Object result = expr.evaluate(doc, XPathConstants.NODESET); NodeList nodes = (NodeList) result; Set<String> set = new HashSet<String>(); for (int i = 0; i < nodes.getLength(); i++) { if (annotation.equals(nodes.item(i).getNodeValue())) { set.add(fetchXPathXpressionOfNode(nodes.item(i))); } } return set; } /** * That is a helping method that take Node and it iterate backword till root node and return the xpath expression * to reach that Node. * @param node * @return */ private static String fetchXPathXpressionOfNode(Node node) { String nodeXPathExpression = null; Node n = node.getParentNode(); while (n != null) { if (n.getNodeName() != null && (n.getNodeName().endsWith("element") || n.getNodeName().endsWith("attribute"))) { if (nodeXPathExpression == null) { nodeXPathExpression = n.getAttributes().getNamedItem("name").getNodeValue(); } else { nodeXPathExpression = n.getAttributes().getNamedItem("name").getNodeValue() + "/" + nodeXPathExpression; } } n = n.getParentNode(); } return nodeXPathExpression; } public static Object getJaxbObjectFromXML(long schemaId, String xmlString) throws JAXBException { JAXBContext jc = JAXBContext.newInstance(FileInfo.GENERATED_PACKAGE + schemaId); ByteArrayInputStream input = new ByteArrayInputStream(xmlString.getBytes()); Unmarshaller u = jc.createUnmarshaller(); return u.unmarshal(input); } public static Document createXMLDocument(byte[] xmlStream) throws Exception { InputStream inStream = new ByteArrayInputStream(xmlStream); DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance(); domFactory.setNamespaceAware(true); DocumentBuilder builder = domFactory.newDocumentBuilder(); return builder.parse(inStream); } public static NodeList readXMLNodes(Document doc, String xpathExpression) throws Exception { XPath xpath = XPathFactory.newInstance().newXPath(); XPathExpression expr = xpath.compile(xpathExpression); Object result = expr.evaluate(doc, XPathConstants.NODESET); return (NodeList) result; } public static String getExceptionMessage(Exception ex) { String msg = ex.getMessage(); if (msg != null) { return msg; } else { try { msg = ""; StackTraceElement[] trace = ex.getStackTrace(); Throwable e1 = ex.getCause(); if (e1 != null) { for (int i = 0; i < trace.length; i++) { if (e1 != null) { msg = e1.getMessage(); if (msg != null) { System.out.println(msg); break; } else { e1 = e1.getCause(); } } } } return msg; } catch (Exception e) { return msg; } } } /** * Safe long to int conversion. * * @param l - long * @return int */ public static int safeLongToInt(long l) { if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) { throw new IllegalArgumentException(l + " cannot be cast to int without changing its value."); } return (int) l; } public static boolean createFileIfNotExist(String className, String sourceCode, File sourceDir) throws Exception { boolean isCreated = false; sourceDir.mkdirs(); String classNamePack = className.replace('.', File.separatorChar); String srcFilePath = sourceDir + "" + File.separatorChar + classNamePack + ".java"; File sourceFile = new File(srcFilePath); if (!sourceFile.exists()) { isCreated = true; FileUtils.writeStringToFile(new File(srcFilePath), sourceCode); } return isCreated; } public static Object getClassInstance(String className, String implementedClassName, Class<?> implementedClass, String sourceCode) throws Exception { DynamicClassLoader dynacode = DynamicClassLoader.getInstance(); Class<?> dynaClass = dynacode.getLoadedClass(className); File sourceDir = new File(System.getProperty("java.io.tmpdir"), "DataCruncher/src"); boolean createFileInTemp = false; if (dynaClass == null) { createFileInTemp = true; } else { boolean isExist = false; @SuppressWarnings("rawtypes") Class[] interfaces = dynaClass.getInterfaces(); if (ArrayUtils.isNotEmpty(interfaces)) { for (Class<?> clz : interfaces) { if ((clz.getName().equalsIgnoreCase(implementedClassName))) { isExist = true; } } } if (!isExist) { createFileInTemp = true; } } if (createFileInTemp) { boolean isCreated = CommonUtils.createFileIfNotExist(className, sourceCode, sourceDir); if (isCreated || dynaClass == null) { dynacode.addSourceDir(sourceDir); return dynacode.newProxyInstance(implementedClass, className); } } return dynaClass.newInstance(); } /** * <p>Checks if the field isn't null and length of the field is greater * than zero not including whitespace.</p> * * @param value The value validation is being performed on. * @return true if blank or null. */ public static boolean isBlankOrNull(String value) { return ((value == null) || (value.trim().length() == 0)); } /* check if the substring is present in a list of strings */ public static boolean isSubStrPresentInList(List<?> elemChecked, String sub) { int i = 0; boolean found = false; String str; while (!found && i < elemChecked.size()) { str = (String) elemChecked.get(i); found = str.startsWith(sub); i++; } return found; } /** * Method took the XPATH set ,XML and returns the List of value for all matching element of Jaxb object. * There's also a method with the same signature except Set -> String * * @param xml * @param xpathXpressionsSet * @param jaxbObject * @return * @throws Exception * @throws SAXException * @throws IOException * @throws XPathExpressionException */ public static Map<String, String> parseXMLandInvokeDoSomething(ByteArrayInputStream xml, Set<String> xpathXpressionsSet, Object jaxbObject) throws Exception, SAXException, IOException, XPathExpressionException { Map<String, String> map = new HashMap<String, String>(); Iterator<String> itr = xpathXpressionsSet.iterator(); while (itr.hasNext()) { String strXPath = itr.next(); List<String> xPath = breakXPathInList(strXPath); if (jaxbObject == null) return map; if (jaxbObject.getClass().isAnnotationPresent(XmlRootElement.class)) { XmlRootElement rootAnnotation = jaxbObject.getClass().getAnnotation(XmlRootElement.class); if (rootAnnotation.name().equals(xPath.get(0))) { recursiveIterateObjectWithXPath(jaxbObject, strXPath, xPath, 1, map); } } else { return map; } } return map; } /** * This method is the same as previous one, but operates only with one set entity (see xpathXpressionsSet). * * @param xml * @param xpathXpression * @param jaxbObject * @return * @throws Exception * @throws SAXException * @throws IOException * @throws XPathExpressionException */ public static String parseXMLandInvokeDoSomething(ByteArrayInputStream xml, String xpathXpression, Object jaxbObject) throws Exception, SAXException, IOException, XPathExpressionException { Map<String, String> map = new HashMap<String, String>(); List<String> xPath = breakXPathInList(xpathXpression); if (jaxbObject == null) return null; if (jaxbObject.getClass().isAnnotationPresent(XmlRootElement.class)) { XmlRootElement rootAnnotation = jaxbObject.getClass().getAnnotation(XmlRootElement.class); if (rootAnnotation.name().equals(xPath.get(0))) { recursiveIterateObjectWithXPath(jaxbObject, xpathXpression, xPath, 1, map); } } //below map values to arrayList casting return map.size() == 1 ? (new ArrayList<String>(map.values())).get(0) : null; } /** * Break XPATH string into the String ArrayList * @param arg * @return */ private static List<String> breakXPathInList(String arg) { ArrayList<String> arrayList = new ArrayList<String>(); StringTokenizer st = new StringTokenizer(arg, "/"); while (st.hasMoreTokens()) arrayList.add(st.nextToken()); return arrayList; } /** * Method recursively iterate all fields * @throws IllegalAccessException * @throws IllegalArgumentException */ private static void recursiveIterateObjectWithXPath(Object obj, String strXPath, List<String> xPath, int location, Map<String, String> map) throws IllegalArgumentException, IllegalAccessException { if (obj == null) return; if (location > xPath.size()) return; Field fields[] = obj.getClass().getDeclaredFields(); for (Field f : fields) { f.setAccessible(true); String xmlElement = null; String xmlElementRef = null; String xmlAttribute = null; if (f.isAnnotationPresent(XmlElement.class)) { xmlElement = f.getAnnotation(XmlElement.class).name(); } else if (f.isAnnotationPresent(XmlElementRef.class)) { xmlAttribute = f.getAnnotation(XmlElementRef.class).name(); } else if (f.isAnnotationPresent(XmlAttribute.class)) { xmlAttribute = f.getAnnotation(XmlAttribute.class).name(); } if (xPath.get(location).equals(xmlElement) || xPath.get(location).equals(f.getName()) || xPath.get(location).equals(xmlElementRef) || xPath.get(location).equals(xmlAttribute)) { Object fieldObject = f.get(obj); if (location + 1 == xPath.size()) { if (fieldObject instanceof JAXBElement) { map.put(strXPath, "" + ((JAXBElement<?>) fieldObject).getValue()); } else { if (fieldObject != null) map.put(strXPath, fieldObject.toString()); } return; } else { if (f.get(obj) instanceof List) { for (Object o : (List<?>) f.get(obj)) { recursiveIterateObjectWithXPath(o, strXPath, xPath, location + 1, map); } } else { recursiveIterateObjectWithXPath(f.get(obj), strXPath, xPath, location + 1, map); } } } } } /** * Download Stream Url . * * @return * @throws Exception */ public static String getDownloadStreamUrl() { String jsp = "downloadstream.json?id_datastream="; ApplicationConfigEntity applicationConfigEntity = applicationConfigDao .findByConfigType(ApplicationConfigType.APPLURL); String outStr = ""; if (applicationConfigEntity != null) outStr = applicationConfigEntity.getHost() + jsp; return outStr; } /** * Gets string array as a comma separated string. * * @param arr * @return */ public static String stringAsCommaSeparated(String[] arr) { String res = ""; for (int i = 0; i < arr.length; i++) { res += arr[i] + ", "; } return res.endsWith(", ") ? res.substring(0, res.length() - 2) : res; } }