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source: MDService2/trunk/MDService2/src/eu/clarin/cmdi/mdservice/action/Cache.java @ 1234

Last change on this file since 1234 was 1234, checked in by vronk, 13 years ago
changes in recordset display, query_detail; adding documenting
File size: 18.7 KB

Rev	Line
[466]	1	package eu.clarin.cmdi.mdservice.action;
	2
[635]	3	import java.io.*;
	4	import java.net.MalformedURLException;
	5	import java.net.URL;
	6	/*import java.io.BufferedWriter;
[466]	7	import java.io.File;
	8	import java.io.FileInputStream;
	9	import java.io.FileNotFoundException;
	10	import java.io.FileReader;
	11	import java.io.FileWriter;
	12	import java.io.IOException;
	13	import java.io.InputStream;
	14	import java.io.Writer;
[635]	15	*/
	16	import java.util.Date;
[980]	17	import java.util.HashMap;
[635]	18	import java.text.DateFormat;
	19	import java.text.SimpleDateFormat;
	20	import java.util.Calendar;
	21
	22	import javax.xml.*;
	23	import javax.xml.parsers.*;
	24	import javax.xml.transform.*;
	25	import javax.xml.transform.sax.*;
[655]	26	import javax.xml.transform.stream.;import javax.xml.transform.dom.;
[635]	27	import javax.xml.xpath.*;
[466]	28
[635]	29	import org.w3c.dom.*;
	30	import org.xml.sax.SAXException;
	31	import org.xml.sax.InputSource;
[704]	32	import org.apache.commons.lang.StringEscapeUtils;
[635]	33
	34
	35	import eu.clarin.cmdi.mdservice.action.Admin;
	36	import eu.clarin.cmdi.mdservice.model.Query;
	37
[466]	38	/**
	39	* This is a rudimentary caching mechanism.
	40	* serializes the inputstream to a file (identifier => filename)
[1234]	41	* and returns the inpustream based on the identifier.
	42	*
	43	* It maintains the cache_index (persisted as xml-file in the cache-folder)
	44	* mapping the request parameters to the indexed files.
	45	*
	46	* This is an internal object, direct user access to cache-data via interface is only possible via <code>AdminAction</code>
[466]	47	* @author master
	48	*
	49	*/
	50	/* TODO: necessary to maintain own index
	51	* for resolution of IDs to filenames
	52	*/
	53
	54
	55	public class Cache {
[635]	56	public static String PREFIX = "xc_";
[466]	57
[689]	58	public static String USE = "use";
	59	public static String REFRESH = "refresh";
	60	public static String SKIP= "skip";
	61
[466]	62	private static Cache singleton;
	63	private String cachepath;
[655]	64	private String cacheindex_path;
[651]	65	private static Integer cachecounter;
[466]	66	private static final Integer start_cache = 1;
	67
[655]	68	private static Document cacheindex_doc;
[466]	69
[676]	70
[466]	71	public Cache () {
	72	cachepath = Admin.getConfig().getProperty("cache.path");
[655]	73	cacheindex_path = cachepath + Admin.getConfig().getProperty("cacheindex.file");
[466]	74	cachecounter = initCachecounter();
[890]	75
[466]	76	}
	77
	78	public static Cache getCache() {
	79	if (singleton == null) {
	80	singleton = new Cache();
	81	}
	82	return singleton;
	83	}
	84
[890]	85	public String getCacheIndexPath() {
	86	return getCache().cacheindex_path;
	87
	88	}
	89
[466]	90	protected void finalize() throws Throwable {
	91	try {
	92	updateCachecounter();
	93	} catch(Exception e) {
	94	}
	95	finally {
	96	super.finalize();
	97	//more code can be written here as per need of application
	98	}
	99	}
	100
	101	/**
[1234]	102	* Here the external key for the data gets cache-internal counter-id assigned
	103	* which is also returned back.
	104	*
	105	* The external key gets parsed and put as individual attributes in the <f>-element:
	106	*
	107	* <code>
	108	* <f collection="" date="2011-04-20 01:06:50" duration="0.227" id="3" lang="en"
	109	* maxDepth="1"
	110	* maximumItems=""
	111	* query=""
	112	* repository="localhost-mirror"
	113	* squery=""
	114	* startItem=""
	115	* type="collections"/>
	116	</code>
	117	*
	118	*
	119	* @param key_info a complex string carrying all relevant parameters
	120	* @param instream data to be stored
[466]	121	* @return
	122	*/
[635]	123	public String putInCache(String key_info, InputStream instream) {
[466]	124
[635]	125	Admin.notifyUser("CACHE.putInCache:"+key_info);
[466]	126	Integer c = getCounter();
[635]	127	String xc;
	128
	129
	130	//update xml_structure
[655]	131	Element e = cacheindex_doc.createElement("f");
	132	//Attr attr = cacheindex_doc.createAttribute("id");
[635]	133	//attr.setValue(c.toString());
	134	//e.setNamedItem(attr);
	135	e.setAttribute("id", c.toString());
[704]	136	String[] key_array = key_info.split("//-");
[635]	137
	138	e.setAttribute("type", key_array[0]);
	139	if (key_array.length > 1){
	140	String query_str;
	141	if (key_array[0].equals("recordset")){
	142	query_str = transformQuery(key_array[1]);
	143	} else {
	144	query_str = key_array[1];
	145	}
	146	e.setAttribute("query", query_str);
	147	}else{
	148	e.setAttribute("query", "");
	149	}
	150	if (key_array.length > 2){
	151	e.setAttribute("collection", key_array[2]);
	152	}else{
	153	e.setAttribute("collection", "");
	154	}
[713]	155	if (key_array.length > 3){
[745]	156	e.setAttribute("squery", key_array[3]);
[713]	157	}else{
[745]	158	e.setAttribute("squery", "");
[713]	159	}
	160	if (key_array.length > 4){
[1069]	161	e.setAttribute("startItem", key_array[4]);
[713]	162	}else{
[1069]	163	e.setAttribute("startItem", "");
[745]	164	}
	165	if (key_array.length > 5){
[1069]	166	e.setAttribute("maximumItems", key_array[5]);
[745]	167	}else{
[1069]	168	e.setAttribute("maximumItems", "");
[713]	169	}
[832]	170
	171	if (key_array.length > 6){
	172	e.setAttribute("repository", key_array[6]);
	173	}else{
	174	e.setAttribute("repository", "");
	175	}
	176	if (key_array.length > 7){
	177	e.setAttribute("maxDepth", key_array[7]);
	178	}else{
	179	e.setAttribute("maxDepth", "");
	180	}
	181	if (key_array.length > 8){
	182	e.setAttribute("lang", key_array[8]);
	183	}else{
	184	e.setAttribute("lang", "");
	185	}
[870]	186	if (key_array.length > 9){
	187	e.setAttribute("duration", key_array[9]);
	188	}else{
	189	e.setAttribute("duration", "");
	190	}
[832]	191
[1029]	192	DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
[635]	193	e.setAttribute("date", dateFormat.format(new Date()).toString());
[655]	194	cacheindex_doc.getFirstChild().appendChild(e);
[635]	195
	196	// update XML-counter
[521]	197	//Admin.writeToFile(formPath(id + xc),instream);
[651]	198
[635]	199	updateCachecounter();
	200
	201	xc = PREFIX + key_array[0] + "_" + c.toString();
[655]	202	Admin.notifyUser("CACHE.putInCache.filename:" + xc + ".xml");
[635]	203	Admin.writeToFile(cachepath + xc + ".xml",instream);
	204
[466]	205	return xc;
	206	}
	207
	208
[635]	209	public InputStream getFromCache(String key_info) {
[655]	210
[635]	211
	212	File f = new File (formPath(key_info));
[1076]	213	//Admin.notifyUser("CACHE.getFromCache:"+key_info);
[655]	214
[676]	215
[466]	216	if (f.exists()) { // read from file to InputStream;
[1076]	217	Admin.notifyUser("CACHE.getFromCache.fromfile:"+f.getName() + "[#" + key_info + "]");
[466]	218	InputStream instream;
	219	try {
[582]	220	instream = new FileInputStream(f);
	221
[466]	222	return instream;
	223	} catch (FileNotFoundException e) {
	224	// TODO Auto-generated catch block
	225	e.printStackTrace();
	226	return null;
	227	}
	228
	229	} else { //not cached, my dear
[1076]	230	Admin.notifyUser("CACHE.getFromCache: NOT CACHED" + "[#" + key_info + "]");
[466]	231	return null;
	232	}
	233	}
	234
[635]	235	private String transformQuery (String str) {
	236	String transformed;
	237	Query query;
	238
[745]	239	if (str == null) return "";
	240	if (str.trim().length() == 0) return "";
	241
[764]	242	// provisional hack, setting simple string to ""
	243	query = new Query("", str,"recordset","");
[635]	244	if (query.isStatus(Query.PARSEERROR)) {
	245	Admin.notifyUser("Cache.transformQuery.PARSEERROR:" + query.getMsg());
	246	// pass this bad news to the client
	247	//setUserMsg(query.getMsg());
	248	transformed = "";
	249	} else {
[774]	250	transformed = Query.getSimpleQueryString(str);
[704]	251	transformed = StringEscapeUtils.escapeXml(transformed);
	252	//Admin.notifyUser("CACHE.transformQuery:"+transformed);
[635]	253	}
	254	return transformed;
	255	}
	256
[980]	257
[466]	258	//TODO: sanitize-key
[635]	259	public String formPath (String key_info) {
	260	String id="";
	261	String path="";
	262	String xpath_expr="";
	263
[704]	264	String[] key_array = key_info.split("//-");
[745]	265	String query_str;
[635]	266
	267	if(key_array.length > 1){
[1076]	268	// Admin.notifyUser("formPATH- querystring:" + key_array[1]);
[635]	269	if (key_array[0].equals("recordset")){
[745]	270	query_str = this.transformQuery(key_array[1]);
[1076]	271	// Admin.notifyUser("formPATH- querystring-transformed:" + query_str);
[635]	272	}
	273	else {
	274	query_str = key_array[1];
	275	}
	276	} else {
	277	query_str = "";
	278	}
	279	xpath_expr = "//index/f[@type='" + key_array[0] + "'";
	280	xpath_expr = xpath_expr + " and @query='"+query_str+"'";
	281
	282	if (key_array.length > 2){
[713]	283	xpath_expr = xpath_expr + "and @collection='"+key_array[2]+"'";
[635]	284	}else{
[713]	285	xpath_expr = xpath_expr + " and @collection=''";
[635]	286	}
[713]	287	if (key_array.length > 3){
[745]	288	xpath_expr = xpath_expr + "and @squery='"+key_array[3]+"'";
[713]	289	}else{
[745]	290	xpath_expr = xpath_expr + " and @squery=''";
[713]	291	}
	292	if (key_array.length > 4){
[1069]	293	xpath_expr = xpath_expr + "and @startItem='"+key_array[4]+"'";
[713]	294	}else{
[1069]	295	xpath_expr = xpath_expr + " and @startItem=''";
[745]	296	}
	297	if (key_array.length > 5){
[1069]	298	xpath_expr = xpath_expr + "and @maximumItems='"+key_array[5]+"'";
[745]	299	}else{
[1069]	300	xpath_expr = xpath_expr + " and @maximumItems=''";
[713]	301	}
[635]	302
[832]	303	if (key_array.length > 6){
	304	xpath_expr = xpath_expr + "and @repository='"+key_array[6]+"'";
	305	}else{
	306	xpath_expr = xpath_expr + " and @repository=''";
	307	}
	308	if (key_array.length > 7){
	309	xpath_expr = xpath_expr + "and @maxDepth='"+key_array[7]+"'";
	310	}else{
	311	xpath_expr = xpath_expr + " and @maxDepth=''";
	312	}
	313	if (key_array.length > 8){
	314	xpath_expr = xpath_expr + "and @lang='"+key_array[8]+"']";
	315	}else{
	316	xpath_expr = xpath_expr + " and @lang='']";
	317	}
	318
[635]	319	//Admin.notifyUser("formPath:xpath:"+xpath_expr);
	320	//creating an XPathFactory:
	321	XPathFactory factory = XPathFactory.newInstance();
	322	//using this factory to create an XPath object:
	323	XPath xpath = factory.newXPath();
	324	//XPath object created compiles the XPath expression:
	325	XPathExpression expr;
	326	try {
	327	expr = xpath.compile(xpath_expr);
	328	//expression is evaluated with respect to a certain context node which is doc.
[655]	329	Object result = expr.evaluate(cacheindex_doc, XPathConstants.NODESET);
[635]	330	NodeList list = (NodeList) result;
	331	if (list.getLength() > 0) {
	332	id = list.item(0).getAttributes().getNamedItem("id").getNodeValue();
	333	path = cachepath + PREFIX + key_array[0] + "_"+id + ".xml";
	334	} else if (list.getLength() > 1){
[745]	335	Admin.notifyUser("formPath ERROR:!!!:multiple paths:"+key_info);
[635]	336
	337	}
	338
	339	} catch (XPathExpressionException e) {
	340	// TODO Auto-generated catch block
[1155]	341	Admin.notifyUser("ERROR Cache.formPath: "+xpath_expr);
[635]	342	}
	343
[466]	344	return path;
	345	}
	346
	347	public Integer getCounter () {
	348	cachecounter = cachecounter +1 ;
	349	return cachecounter;
	350	}
	351
	352	/**
	353	* read counter-integer from file in cache
	354	* or start that file
	355	* @return
	356	*/
	357	public Integer initCachecounter() {
[635]	358
	359	Integer counter = start_cache;
[466]	360	boolean init=false;
[655]	361	String fname = cacheindex_path;
[635]	362	File f = new File (fname);
	363
	364	//Admin.notifyUser("initCacheCounter");
	365	if (!f.exists()) {
	366	// create new counter document
	367	DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
	368	DocumentBuilder docBuilder;
	369	try {
	370	docBuilder = docFactory.newDocumentBuilder();
[655]	371	cacheindex_doc = docBuilder.newDocument();
[635]	372	// append root tag <index >
[655]	373	Element root = (Element) cacheindex_doc.createElement("index");
[635]	374	root.setAttribute("idcounter", "1");
[655]	375	cacheindex_doc.appendChild(root);
[635]	376	writeCachecounter(counter);
	377
	378	//Admin.notifyUser("new document");
	379	} catch (ParserConfigurationException e) {
	380	// TODO Auto-generated catch block
	381	e.printStackTrace();
	382	}
	383
	384	//} catch (IOException e2) {
	385	// Admin.notifyUser("ERROR creating cache counter");
	386	// e2.printStackTrace();
	387	//}
	388	}
	389	else {
[466]	390	try {
[635]	391
	392	DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
	393	DocumentBuilder docBuilder;
	394	try {
	395	docBuilder = docFactory.newDocumentBuilder();
	396	try {
[655]	397	cacheindex_doc = docBuilder.parse(fname);
[635]	398	} catch (SAXException e) {
	399	// TODO Auto-generated catch block
	400
	401	e.printStackTrace();
	402	}
	403	} catch (ParserConfigurationException e) {
	404	// TODO Auto-generated catch block
	405	e.printStackTrace();
	406	}
	407
	408	//read counter
[655]	409	counter = new Integer(cacheindex_doc.getFirstChild().getAttributes().getNamedItem("idcounter").getNodeValue());
[635]	410	init = true;
	411	} catch (IOException ex){
	412	//Admin.notifyUser("initCacheCounter:" + ex.toString());
	413	ex.printStackTrace();
	414	}
	415	}
	416
	417	return counter;
	418	/*
[466]	419	//use buffering, reading one line at a time
	420	//FileReader always assumes default encoding is OK!
	421	BufferedReader input = new BufferedReader(new FileReader(f));
	422	try {
	423	String line = null; //not declared within while loop
	424	/*
	425	* readLine is a bit quirky :
	426	* it returns the content of a line MINUS the newline.
	427	* it returns null only for the END of the stream.
	428	* it returns an empty String if two newlines appear in a row.
[635]	429	*
[466]	430	try {
	431	if (( line = input.readLine()) != null){
	432	try {
	433	counter = new Integer(line);
	434	} catch (NumberFormatException e) {
	435	// if not a number, write a number
	436	init=true;
	437	}
	438	} else {
	439	init=true;
	440	}
	441	} catch (IOException e) {
	442	init=true;
	443	}
	444
	445	if (init) {
	446	writeCachecounter( start_cache);
	447	}
	448
	449	} finally {
	450	input.close();
[635]	451	}
	452	*/
[466]	453	}
	454
	455	public void updateCachecounter () {
[656]	456	//Admin.notifyUser("CACHEcounter:" + cachecounter);
[466]	457	writeCachecounter( cachecounter);
	458	}
[655]	459	public void writeCachecounter (Integer i) {
[635]	460
	461	// first update <index idcounter>
[655]	462	cacheindex_doc.getFirstChild().getAttributes().getNamedItem("idcounter").setNodeValue(i.toString());
[635]	463
	464	//Admin.notifyUser("writeCacheCounter:" + i.toString());
	465	// write xml
	466	Transformer transformer;
	467	try {
	468	transformer = TransformerFactory.newInstance().newTransformer();
	469	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	470
	471	//initialize StreamResult with File object to save to file
	472	StreamResult result = new StreamResult(new StringWriter());
[655]	473	DOMSource source = new DOMSource(cacheindex_doc);
[635]	474	try {
	475	transformer.transform(source, result);
	476	} catch (TransformerException e1) {
	477	// TODO Auto-generated catch block
	478	e1.printStackTrace();
	479	}
	480
	481	String xmlString = result.getWriter().toString();
	482	//Admin.notifyUser("writeCacheCounter:" + xmlString);
	483	//Admin.writeToFile("", result);
	484
	485
[655]	486	File f = new File (cacheindex_path);
[635]	487	FileWriter fw;
	488	try {
	489	fw = new FileWriter(f);
	490	try {
	491	fw.write(xmlString);
	492	fw.close();
	493	} catch (IOException e) {
	494	// TODO Auto-generated catch block
	495	e.printStackTrace();
	496	}
	497	} catch (IOException e) {
	498	// TODO Auto-generated catch block
	499	e.printStackTrace();
	500	}
	501	} catch (TransformerConfigurationException e2) {
	502	// TODO Auto-generated catch block
	503	e2.printStackTrace();
	504	} catch (TransformerFactoryConfigurationError e2) {
	505	// TODO Auto-generated catch block
	506	e2.printStackTrace();
	507	}
	508
	509
	510
	511	/*
[466]	512	File f = new File (Admin.getConfig().getProperty("cache.path") + "counter.txt");
	513
	514	try {
	515	Writer output = new BufferedWriter(new FileWriter(f));
	516	//FileWriter always assumes default encoding is OK!
	517	try {
	518	output.write( i);
	519	} finally {
	520	output.close();
	521	}
	522	} catch (IOException e) {
	523	// TODO Auto-generated catch block
	524	e.printStackTrace();
	525	}
[635]	526	*/
[466]	527	}
[980]	528
	529	public InputStream clear(HashMap<String,String> clear_params) throws ParserConfigurationException, TransformerConfigurationException, TransformerException, TransformerFactoryConfigurationError {
	530	String xpath_expr = "";
	531	Integer removed = 0;
	532	InputStream is = null;
	533
	534	if (clear_params.size() > 0 ) {
	535	if (clear_params.containsKey("repository")){
	536	xpath_expr = xpath_expr + " and @repository='" + clear_params.get("repository") + "'";
	537	}
	538	if (clear_params.containsKey("type")){
	539	xpath_expr = xpath_expr + " and @type='" + clear_params.get("type") + "'";
	540	}
	541	if (clear_params.containsKey("date")){
	542	xpath_expr = xpath_expr + " and @date='" + clear_params.get("date") + "'";
	543	}
	544	if (clear_params.containsKey("datefrom")){
	545	xpath_expr = xpath_expr + " and @date >= '" + clear_params.get("datefrom") + "'";
	546	}
	547	if (clear_params.containsKey("dateto")){
	548	xpath_expr = xpath_expr + " and @date <= '" + clear_params.get("dateto") + "'";
	549	}
	550	if (xpath_expr.length()>0){
	551	xpath_expr = xpath_expr.substring(5);
	552	}
	553	xpath_expr = "//index/f[" + xpath_expr + "]";
	554	} else {
	555	xpath_expr = "//index/f";
	556	}
	557
	558	////////// remove index_lines + files
	559	String id,type,path;
	560	File f;
	561	//creating an XPathFactory:
	562	XPathFactory factory = XPathFactory.newInstance();
	563	//using this factory to create an XPath object:
	564	XPath xpath = factory.newXPath();
	565	//XPath object created compiles the XPath expression:
	566	XPathExpression expr;
	567	try {
	568	expr = xpath.compile(xpath_expr);
	569	//expression is evaluated with respect to a certain context node which is doc.
	570	Object result = expr.evaluate(cacheindex_doc, XPathConstants.NODESET);
	571	NodeList list = (NodeList) result;
	572
	573	//create deleted_doc
	574	DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
	575	DocumentBuilder docBuilder;
	576	docBuilder = docFactory.newDocumentBuilder();
	577	Document deleted_doc = docBuilder.newDocument();
	578	Element root = (Element) deleted_doc.createElement("index");
	579	root.setAttribute("count_deleted", String.valueOf(list.getLength()) );
	580	deleted_doc.appendChild(root);
	581
	582	// delete items
	583	for(int i = 0;i< list.getLength();i++){
	584
	585	id = list.item(i).getAttributes().getNamedItem("id").getNodeValue();
	586	type = list.item(i).getAttributes().getNamedItem("type").getNodeValue();
	587	path = cachepath + PREFIX + type + "_"+id + ".xml";
	588	f = new File (path);
	589
	590	f.delete();
	591	cacheindex_doc.getFirstChild().removeChild(list.item(i));
	592
	593	Element e = deleted_doc.createElement("f");
	594	e.setAttribute("filename", path);
	595	e.setAttribute("id", id);
	596	deleted_doc.getFirstChild().appendChild(e);
	597	}
	598
	599	//create resultstream
	600	ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
	601	Source xmlSource = new DOMSource(deleted_doc);
	602	Result outputTarget = new StreamResult(outputStream);
	603	TransformerFactory.newInstance().newTransformer().transform(xmlSource, outputTarget);
	604	is = new ByteArrayInputStream(outputStream.toByteArray());
	605
	606	removed = list.getLength();
	607
	608	} catch (XPathExpressionException e) {
	609	// TODO Auto-generated catch block
	610	e.printStackTrace();
	611	}
	612
	613	//////// set the index value
	614	NodeList nl = cacheindex_doc.getElementsByTagName("f");
	615	if (nl.getLength() < 1){
	616	cachecounter = 1;
	617	}else {
	618	cachecounter = Integer.parseInt(nl.item(nl.getLength()-1).getAttributes().getNamedItem("id").getNodeValue());
	619	}
	620	this.updateCachecounter();
	621	return is;
	622	}
	623
[466]	624	}

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