java managed server bean crashes - java

Why would I not be able to call this multiple times?
private Document getStationery(String txtStationery,Database mailDB){
try {
View mailView = mailDB.getView("(Stationery)");
DocumentCollection dc = mailView.getAllDocumentsByKey("Memo Stationery");
Document tmpdoc;
Document doc = dc.getFirstDocument();
while (doc != null) {
if(doc.getItemValueString("MailStationeryName").equals(txtStationery))
{
return doc;
}
tmpdoc = dc.getNextDocument();
doc.recycle();
doc = tmpdoc;
}
} catch (NotesException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
Crashes on second use of it below .... something to do with not recycling?
public void send() throws NotesException, IOException, Exception{
Session session = getCurrentSession();
Database userDB = getUserDatabase();
Database mailbox = session.getDatabase("", "mail1.box");
Document stationeryDoc1 = getStationery("Test1",userDB);
Document stationeryDoc2 = getStationery("Test2",userDB);

You could try without recycling at all (generally not a good idea, but here it may be helpful to rule out other problems), or recycle the objects in the getStationary() method properly, beginning with the Document, the DocumentCollection, and finally the View. At the moment, the only object you recycle is the previous Document object in the while loop.

Related

How to load custom XML feed with Jsoup?

I have a Java-method that gets a feed-document (via http) and then parses the feed (which is not of-type JSON or XML).
This is the method:
public ArrayList<ArrayList<String>> getFeed(String type)
{
String feed = "";
String address = "";
Document file;
/**
* FEED URLs-------\/
*/
switch (type) {
case "news":
address = "https://[domain]/svc/feeds/news/6001?subtree=false&imagesize=medium-square";
break;
case "events":
address = "http://[domain]/svc/feeds/events/6001?subtree=true&imagesize=medium-square&from=%5bfromDate%5d&to=%5btoDate";
}
try {
HttpURLConnection connection = (HttpURLConnection) (new URL(address)).openConnection();
//TODO: #Test
//----------------------------\/--THIS ONE WILL CAUSE ERRORS!!
file = (Document)connection.getContent();
connection.disconnect();
//OUTPUT
feed = file.getElementsByAttribute("pre").text();
stream = new StringReader(feed);
} catch (Exception e) {}
//BEGIN PARSING\\//--THEN OUTPUT//\\
try {
return parse();
} catch (FeedParseException e) {}
//de-fault
return null;
}
It's not working; saying that object:'file' caused NullPointerException.
So how do I increase my precision in debugging something which seems to me to be non-Open-Source.
P.S.: I'm not testing the "events" case so don't worry about the GET-parameters there.
here's my stack-trace:
I don't see how it helps though...
You can pass to Jsoup the URL object directly.
Instead of:
HttpURLConnection connection = (HttpURLConnection) (new URL(address)).openConnection();
//TODO: #Test
//----------------------------\/--THIS ONE WILL CAUSE ERRORS!!
file = (Document)connection.getContent();
connection.disconnect();
do
file = Jsoup //
.connect(address) //
.timeout( 10 * 1000) //
.ignoreContentType(true) //
.get();
Jsoup 1.8.3

Parsing Google news in Java

What is the best way to do that?
I want to parse the news and, then, filter them using something like keyword and find the match.
Someone has already done? And, it is lawful?
You can use rss feeds of google news url http://news.google.com/?output=rss it will return google rss news in the rss tag with html tags. Then either write custom code to read/parse the xml or using any existing RSS reading library like https://github.com/vgrec/SimpleRssReader
I have written a function to accomplish this which will return link and title of the random news each time.
public Document getNews() {
Document news = new Document();
URL rssUrl = null;
try {
rssUrl = new URL("https://news.google.com/rss");
} catch (MalformedURLException e) {
e.printStackTrace();
}
DocumentBuilder builder = null;
try {
builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
org.w3c.dom.Document doc = null;
try {
doc = builder.parse(rssUrl.openStream());
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
NodeList items = doc.getElementsByTagName("item");
Element item = (Element) items.item(new Random().nextInt(items.getLength()));
news.append("title", getValue(item, "title"));
news.append("link", getValue(item, "link"));
return news;
}
private String getValue(Element parent, String nodeName) {
return parent.getElementsByTagName(nodeName).item(0).getFirstChild().toString();
}

How to write a unit test for an XML parser I wrote in Java

The context is as follows:
I've got objects that represent Tweets (from Twitter). Each object has an id, a date and the id of the original tweet (if there was one).
I receive a file of tweets (where each tweet is in the format of 05/04/2014 12:00:00, tweetID, originalID and is in its' own line) and I want to save them as an XML file where each field has its' own tag.
I want to then be able to read the file and return a list of Tweet objects corresponding to the Tweets from the XML file.
After writing the XML parser that does this I want to test that it works correctly. I've got no idea how to test this.
The XML Parser:
public class TweetToXMLConverter implements TweetImporterExporter {
//there is a single file used for the tweets database
static final String xmlPath = "src/main/resources/tweetsDataBase.xml";
//some "defines", as we like to call them ;)
static final String DB_HEADER = "tweetDataBase";
static final String TWEET_HEADER = "tweet";
static final String TWEET_ID_FIELD = "id";
static final String TWEET_ORIGIN_ID_FIELD = "original tweet";
static final String TWEET_DATE_FIELD = "tweet date";
static File xmlFile;
static boolean initialized = false;
#Override
public void createDB() {
try {
Element tweetDB = new Element(DB_HEADER);
Document doc = new Document(tweetDB);
doc.setRootElement(tweetDB);
XMLOutputter xmlOutput = new XMLOutputter();
// display nice nice? WTF does that chinese whacko want?
xmlOutput.setFormat(Format.getPrettyFormat());
xmlOutput.output(doc, new FileWriter(xmlPath));
xmlFile = new File(xmlPath);
initialized = true;
} catch (IOException io) {
System.out.println(io.getMessage());
}
}
#Override
public void addTweet(Tweet tweet) {
if (!initialized) {
//TODO throw an exception? should not come to pass!
return;
}
SAXBuilder builder = new SAXBuilder();
try {
Document document = (Document) builder.build(xmlFile);
Element newTweet = new Element(TWEET_HEADER);
newTweet.setAttribute(new Attribute(TWEET_ID_FIELD, tweet.getTweetID()));
newTweet.setAttribute(new Attribute(TWEET_DATE_FIELD, tweet.getDate().toString()));
if (tweet.isRetweet())
newTweet.addContent(new Element(TWEET_ORIGIN_ID_FIELD).setText(tweet.getOriginalTweet()));
document.getRootElement().addContent(newTweet);
} catch (IOException io) {
System.out.println(io.getMessage());
} catch (JDOMException jdomex) {
System.out.println(jdomex.getMessage());
}
}
//break glass in case of emergency
#Override
public void addListOfTweets(List<Tweet> list) {
for (Tweet t : list) {
addTweet(t);
}
}
#Override
public List<Tweet> getListOfTweets() {
if (!initialized) {
//TODO throw an exception? should not come to pass!
return null;
}
try {
SAXBuilder builder = new SAXBuilder();
Document document;
document = (Document) builder.build(xmlFile);
List<Tweet> $ = new ArrayList<Tweet>();
for (Object o : document.getRootElement().getChildren(TWEET_HEADER)) {
Element rawTweet = (Element) o;
String id = rawTweet.getAttributeValue(TWEET_ID_FIELD);
String original = rawTweet.getChildText(TWEET_ORIGIN_ID_FIELD);
Date date = new Date(rawTweet.getAttributeValue(TWEET_DATE_FIELD));
$.add(new Tweet(id, original, date));
}
return $;
} catch (JDOMException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
Some usage:
private TweetImporterExporter converter;
List<Tweet> tweetList = converter.getListOfTweets();
for (String tweetString : lines)
converter.addTweet(new Tweet(tweetString));
How can I make sure the the XML file I read (that contains tweets) corresponds to the file I receive (in the form stated above)?
How can I make sure the tweets I add to the file correspond to the ones I tried to add?
Assuming that you have the following model:
public class Tweet {
private Long id;
private Date date;
private Long originalTweetid;
//getters and seters
}
The process would be the following:
create an isntance of TweetToXMLConverter
create a list of Tweet instances that you expect to receive after parsing the file
feed the converter the list you generated
compare the list received by parsing the list and the list you initiated at the start of the test
public class MainTest {
private TweetToXMLConverter converter;
private List<Tweet> tweets;
#Before
public void setup() {
Tweet tweet = new Tweet(1, "05/04/2014 12:00:00", 2);
Tweet tweet2 = new Tweet(2, "06/04/2014 12:00:00", 1);
Tweet tweet3 = new Tweet(3, "07/04/2014 12:00:00", 2);
tweets.add(tweet);
tweets.add(tweet2);
tweets.add(tweet3);
converter = new TweetToXMLConverter();
converter.addListOfTweets(tweets);
}
#Test
public void testParse() {
List<Tweet> parsedTweets = converter.getListOfTweets();
Assert.assertEquals(parsedTweets.size(), tweets.size());
for (int i=0; i<parsedTweets.size(); i++) {
//assuming that both lists are sorted
Assert.assertEquals(parsedTweets.get(i), tweets.get(i));
};
}
}
I am using JUnit for the actual testing.

SAXException unable to get document encoding

I'm trying to make an application that displays news feed from a website so I get the input stream and parse it in document using SAX but it returns SAX exception that it is unable to determine type of coding of this Stream . I tried before that to put The website's stream manually in XML file and read the file and It worked but when streaming directly from Internet it throws that exception and this is my code :
public final class MyScreen extends MainScreen {
protected static RichTextField RTF = new RichTextField("Plz Wait . . . ",
Field.FIELD_BOTTOM);
public MyScreen() {
// Set the displayed title of the screen
super(Manager.NO_VERTICAL_SCROLL);
setTitle("Yalla Kora");
Runnable R = new Runnable();
R.start();
add(RTF);
}
private class Runnable extends Thread {
public Runnable() {
// TODO Auto-generated constructor stub
ConnectionFactory factory = new ConnectionFactory();
ConnectionDescriptor descriptor = factory
.getConnection("http://www.yallakora.com/arabic/rss.aspx?id=0");
HttpConnection httpConnection;
httpConnection = (HttpConnection) descriptor.getConnection();// Connector.open("http://www.yallakora.com/pictures/main//2011/11/El-Masry-807-11-2011-21-56-7.jpg");
Manager mainManager = getMainManager();
RichList RL = new RichList(mainManager, true, 2, 1);
InputStream input;
try {
input = httpConnection.openInputStream();
Document document;
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder docBuilder;
try {
docBuilder = docBuilderFactory.newDocumentBuilder();
docBuilder.isValidating();
try {
document = docBuilder.parse(input);
document.getDocumentElement().normalize();
NodeList item = document.getElementsByTagName("item");
int k = item.getLength();
for (int i = 0; i < k; i++) {
Node value = item.item(i);
NodeList Data = value.getChildNodes();
Node title = Data.item(0);
Node link = Data.item(1);
Node date = Data.item(2);
Node discription = Data.item(5);
Node Discription = discription.getFirstChild();
String s = Discription.getNodeValue();
int mm = s.indexOf("'><BR>");
int max = s.length();
String imagelink = s.substring(0, mm);
String Khabar = s.substring(mm + 6, max);
String Date = date.getFirstChild().getNodeValue();
String Title = title.getFirstChild().getNodeValue();
String Link = link.getFirstChild().getNodeValue();
ConnectionFactory factory1 = new ConnectionFactory();
ConnectionDescriptor descriptor1 = factory1
.getConnection(imagelink);
HttpConnection httpConnection1;
httpConnection1 = (HttpConnection) descriptor1
.getConnection();
InputStream input1;
input1 = httpConnection1.openInputStream();
byte[] bytes = IOUtilities.streamToBytes(input1);
Bitmap bitmap = Bitmap.createBitmapFromBytes(bytes,
0, -1, 1);
;
RL.add(new Object[] { bitmap, Title, Khabar, Date });
add(new RichTextField(link.getNodeValue(),
Field.NON_FOCUSABLE));
}
RTF.setText("");
} catch (SAXException e) {
// TODO Auto-generated catch block
RTF.setText("SAXException " + e.toString());
e.printStackTrace();
}
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
RTF.setText("ParserConfigurationException " + e.toString());
e.printStackTrace();
}
} catch (IOException e) {
RTF.setText("IOException " + e.toString());
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}}
Any Ideas ??
I recommend restructuring this code into at least two parts.
I would create a download function that is given a URL and downloads the bytes associated with that URL. This should open and close the connection, and just return either the bytes downloaded or an error indication.
I would use this download processing as a 'function call' to download your XML bytes. Then parse the bytes that are obtained feeding these direct into your parser. If the data is properly constructed XML, it will have a header indicating the encoding used, so you do not need to worry about that, the parser will cope.
Once you have this parsed, then use the download function again to download the bytes associated with any images you want.
Regarding the SAX processing, have you reviewed this question:
parse-xml-inputstream-in-blackberry-java-application

Parsing XML from a website to a String array in Android please help me

Hello I am in the process of making an Android app that pulls some data from a Wiki, at first I was planning on finding a way to parse the HTML, but from something that someone pointed out to me is that XML would be much easier to work with. Now I am stuck trying to find a way to parse the XML correctly. I am trying to parse from a web address right now from:
http://zelda.wikia.com/api.php?action=query&list=categorymembers&cmtitle=Category:Games&cmlimit=500&format=xml
I am trying to get the titles of each of the games into a string array and I am having some trouble. I don't have an example of the code I was trying out, it was by using xmlpullparser. My app crashes everytime that I try to do anything with it. Would it be better to save the XML locally and parse from there? or would I be okay going from the web address? and how would I go about parsing this correctly into a string array? Please help me, and thank you for taking the time to read this.
If you need to see code or anything I can get it later tonight, I am just not near my PC at this time. Thank you.
Whenever you find yourself writing parser code for simple formats like the one in your example you're almost always doing something wrong and not using a suitable framework.
For instance - there's a set of simple helpers for parsing XML in the android.sax package included in the SDK and it just happens that the example you posted could be easily parsed like this:
public class WikiParser {
public static class Cm {
public String mPageId;
public String mNs;
public String mTitle;
}
private static class CmListener implements StartElementListener {
final List<Cm> mCms;
CmListener(List<Cm> cms) {
mCms = cms;
}
#Override
public void start(Attributes attributes) {
Cm cm = new Cm();
cm.mPageId = attributes.getValue("", "pageid");
cm.mNs = attributes.getValue("", "ns");
cm.mTitle = attributes.getValue("", "title");
mCms.add(cm);
}
}
public void parseInto(URL url, List<Cm> cms) throws IOException, SAXException {
HttpURLConnection con = (HttpURLConnection) url.openConnection();
try {
parseInto(new BufferedInputStream(con.getInputStream()), cms);
} finally {
con.disconnect();
}
}
public void parseInto(InputStream docStream, List<Cm> cms) throws IOException, SAXException {
RootElement api = new RootElement("api");
Element query = api.requireChild("query");
Element categoryMembers = query.requireChild("categorymembers");
Element cm = categoryMembers.requireChild("cm");
cm.setStartElementListener(new CmListener(cms));
Xml.parse(docStream, Encoding.UTF_8, api.getContentHandler());
}
}
Basically, called like this:
WikiParser p = new WikiParser();
ArrayList<WikiParser.Cm> res = new ArrayList<WikiParser.Cm>();
try {
p.parseInto(new URL("http://zelda.wikia.com/api.php?action=query&list=categorymembers&cmtitle=Category:Games&cmlimit=500&format=xml"), res);
} catch (MalformedURLException e) {
} catch (IOException e) {
} catch (SAXException e) {}
Edit: This is how you'd create a List<String> instead:
public class WikiParser {
private static class CmListener implements StartElementListener {
final List<String> mTitles;
CmListener(List<String> titles) {
mTitles = titles;
}
#Override
public void start(Attributes attributes) {
String title = attributes.getValue("", "title");
if (!TextUtils.isEmpty(title)) {
mTitles.add(title);
}
}
}
public void parseInto(URL url, List<String> titles) throws IOException, SAXException {
HttpURLConnection con = (HttpURLConnection) url.openConnection();
try {
parseInto(new BufferedInputStream(con.getInputStream()), titles);
} finally {
con.disconnect();
}
}
public void parseInto(InputStream docStream, List<String> titles) throws IOException, SAXException {
RootElement api = new RootElement("api");
Element query = api.requireChild("query");
Element categoryMembers = query.requireChild("categorymembers");
Element cm = categoryMembers.requireChild("cm");
cm.setStartElementListener(new CmListener(titles));
Xml.parse(docStream, Encoding.UTF_8, api.getContentHandler());
}
}
and then:
WikiParser p = new WikiParser();
ArrayList<String> titles = new ArrayList<String>();
try {
p.parseInto(new URL("http://zelda.wikia.com/api.php?action=query&list=categorymembers&cmtitle=Category:Games&cmlimit=500&format=xml"), titles);
} catch (MalformedURLException e) {
} catch (IOException e) {
} catch (SAXException e) {}

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