Search Results

Search found 32961 results on 1319 pages for 'java'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 853/1319 | < Previous Page | 849 850 851 852 853 854 855 856 857 858 859 860  | Next Page >

  • Loading child entities with JPA on Google App Engine

    - by Phil H
    I am not able to get child entities to load once they are persisted on Google App Engine. I am certain that they are saving because I can see them in the datastore. For example if I have the following two entities. public class Parent implements Serializable{ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true") private String key; @OneToMany(cascade=CascadeType.ALL) private List<Child> children = new ArrayList<Child>(); //getters and setters } public class Child implements Serializable{ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true") private String key; private String name; @ManyToOne private Parent parent; //getters and setters } I can save the parent and a child just fine using the following: Parent parent = new Parent(); Child child = new Child(); child.setName("Child Object"); parent.getChildren().add(child); em.persist(parent); However when I try to load the parent and then try to access the children (I know GAE lazy loads) I do not get the child records. //parent already successfully loaded parent.getChildren.size(); // this returns 0 I've looked at tutorial after tutorial and nothing has worked so far. I'm using version 1.3.3.1 of the SDK. I've seen the problem mentioned on various blogs and even the App Engine forums but the answer is always JDO related. Am I doing something wrong or has anyone else had this problem and solved it for JPA?

    Read the article

  • Decorator Pattern - Multiple wrappers or quantity property?

    - by Jiminizer
    I'm making use of the decorator pattern for one of the first times, as part of a Uni project. As far as I can see, the pattern seems to be meant more for adding functionality in a modular manner, however we've been taught it with uses such as a coffee or pizza maker, where the object has modular components that are added - changing properties rather than behaviour. I'm trying to make the most of both uses, however I've come up with a question. In the example in the book we're using (Head First Design Patterns), the pattern is used in a coffee shop creating different coffees. So, for example, milk, froth, sugar, sprinkles are all decorators. How would you implement a system that used the same decorator multiple times (for example, a coffee with two sugars)? Would you rewrap the coffee, or give sugar a quantity property? Or (as i'm starting to suspect) would this never be an issue as the pattern isn't designed to be used this way?

    Read the article

  • Reflection: take values from an unknown running alpplication

    - by Dr.Lesh
    I'm writing an application that searchs for Semaphore types in the fields of unknown classes in unknown application (passed by user). I made it using Reflection and it worked. Now I want to fill up these semaphores with values, taking them from a running instance of this unknown application. So i took the class with "main" method of this unknown application, made a newInstance, and passed it when invoking the main method to start the application: Class mainClass = getItSomeWhere(); Object instance = mainClass.newInstance(); Method mainMethod = mainClass.getDeclaredMethod("main", new Class[]{String[].class}); mainMethod.invoke(instance, new Object[]{args}); and it worked fine. Now, how can I get the semaphore values, taking them from the classes of this running application, when I only have an instance of the main class? Many thanks for the answers.

    Read the article

  • How to login to gdata in GWT application deployed on GAE?

    - by Raffo
    I want to use the Google account login to retrieve the informations to be used for Google's gdata api so that when I start the application deployed on Google App Engine the user is asked for its login and I can then use this information on the server side to specify the credentials for Google Calendar login (through gdata api). How can I do that? I tried using Client login but it seems that there's no way to get password information from che Client object on the server side... thank you.

    Read the article

  • abstract class need acces to subclass atribute

    - by user1742980
    I have a problem with my code. public abstract class SimplePolygon implements Polygon { ... public String toString(){ String str = "Polygon: vertices ="; for(int i = 0;i<varray.length;i++){ str += " "; str += varray[i]; } return str; } } public class ArrayPolygon extends SimplePolygon { private Vertex2D[] varray; public ArrayPolygon(Vertex2D[] array){ varray = new Vertex2D[array.length]; if (array == null){} for(int i = 0;i<array.length;i++){ if (array[i] == null){} varray[i] = array[i]; } ... } Problem is, that i'm not allowed to add any atribute or method to abstract class SimplePolygon, so i'cant properly initialize varray. It could simply be solved with protected atrib in that class, but for some (stupid) reason i'cant do that. Has anybody an idea how to solve it without that? Thanks for all help.

    Read the article

  • about Sorting Algorithms

    - by matin1234
    Hi I want to know that we always use Sorting algorithm like (Insertion Sort or Merge Sort,...) just for lists and arrays?? and we do not use these algorithms for stack or queue ??? thanks

    Read the article

  • Doubt in abstract classes

    - by mohit
    public abstract class Person { private String name; public Person(String name) { this.name = name; System.out.println("Person"); } public String getName() { return name; } abstract public String getDescription(); } public class Student extends Person { private String major; public Student(String name, String major) { super(name); this.major = major; } public String getMajor() { return major; } @Override public String getDescription() { return "student" + super.getName() + " having" + major; } } public class PersonTest { public static void main(String[] args) { Person person = new Student("XYZ", "ABC"); System.out.println(person.getDescription()); } } Ques: We cannot create objects of abstract classes, then why Person Constructor has been invoked, even its an abstract class?

    Read the article

  • Hibernate querycount query, dont know how to do

    - by kevinb92
    I want to make an hibernate querycount on a table. I have to values, one string and one boolean HibernateUtil.queryCount(VoteOnPublication.class, new String[] {VOTED_PUBLICATION_ID_FIELD, FOR_OR_AGAINST_FIELD}, **********); my voted_publication_id_field is a string, and my for or against field is a boolean. What should i put in my second part of the query ? I first put : new String[] {publication.getId(),true.toString() but that didnt work. i think the new String is the mistake but i dont know what to put

    Read the article

  • How do you set a double value to a "non-value"

    - by Ankur
    I have two double data elements in an object. Sometimes they are set with a proper value and sometimes not. When the form field from which they values are received is not filled I want to set them to some value that tells me, during the rest of the code that the form fields were left empty. I can't set the values to null as that gives an error, is there some way I can make them 'Undefined'. PS. Not only am I not sure that this is possible, it might not also make sense. But if there is some best practice for such a situation I would be keen to hear it.

    Read the article

  • IO Exception on invoking execute() method of HttpGet class

    - by AndroidNoob
    Why I'm getting IOException in this peace of code? Thanks. HttpClient httpclient = new DefaultHttpClient(); HttpGet httpget = new HttpGet("http://www.google.com/"); HttpResponse response; try { response = httpclient.execute(httpget); } catch (ClientProtocolException e) { Toast.makeText(this, "ClientProtocolEx", Toast.LENGTH_LONG).show(); e.printStackTrace(); } catch (IOException e) { Toast.makeText(this, "IOEx", Toast.LENGTH_LONG).show(); e.printStackTrace(); }

    Read the article

  • String doesn't match regex when read from keyboard.

    - by athspk
    public static void main(String[] args) throws IOException { String str1 = "??123456"; System.out.println(str1+"-"+str1.matches("^\\p{InGreek}{2}\\d{6}")); //??123456-true BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String str2 = br.readLine(); //??123456 same as str1. System.out.println(str2+"-"+str2.matches("^\\p{InGreek}{2}\\d{6}")); //?”??123456-false System.out.println(str1.equals(str2)); //false } The same String doesn't match regex when read from keyboard. What causes this problem, and how can we solve this? Thanks in advance. EDIT: I used System.console() for input and output. public static void main(String[] args) throws IOException { PrintWriter pr = System.console().writer(); String str1 = "??123456"; pr.println(str1+"-"+str1.matches("^\\p{InGreek}{2}\\d{6}")+"-"+str1.length()); String str2 = System.console().readLine(); pr.println(str2+"-"+str2.matches("^\\p{InGreek}{2}\\d{6}")+"-"+str2.length()); pr.println("str1.equals(str2)="+str1.equals(str2)); } Output: ??123456-true-8 ??123456 ??123456-true-8 str1.equals(str2)=true

    Read the article

  • 3D array initialization

    - by xdevel2000
    I need to represent some spatial points: x,y,z when I try to initialize the array like this: int[][][] points { { {100, 120, 10}, {100, 120, 18}, ... } } I got an error: Uncompilable source code - not a statement where is the error?

    Read the article

  • JDBC Connection pool monitoring GlassFish

    - by john
    I am trying to find a setting by which the connection pool monitoring information would come in the server.log whenever an error like "error allocating a connection" or "connection closed" occur. I found some blog entries that talk about this but they mention it from GUI prespective. However, I want a setting on the connection pool itself so that perodically the connection pool monitoring information would be shown in the logs. Does anyone know of such a setting? On Sun app Server 8.X it used to be perf-monitor

    Read the article

  • When I try to redefine a variable, I get an index out of bounds error

    - by user2770254
    I'm building a program to act as a calculator with memory, so you can give variables and their values. Whenever I'm trying to redefine a variable, a = 5, to a = 6, I get an index out of bounds error. public static void main(String args[]) { LinkedHashMap<String,Integer> map = new LinkedHashMap<String,Integer>(); Scanner scan = new Scanner(System.in); ArrayList<Integer> values = new ArrayList<>(); ArrayList<String> variables = new ArrayList<>(); while(scan.hasNextLine()) { String line = scan.nextLine(); String[] tokens = line.split(" "); if(!Character.isDigit(tokens[0].charAt(0)) && !line.equals("clear") && !line.equals("var")) { int value = 0; for(int i=0; i<tokens.length; i++) { if(tokens.length==3) { value = Integer.parseInt(tokens[2]); System.out.printf("%5d\n",value); if(map.containsKey(tokens[0])) { values.set(values.indexOf(tokens[0]), value); variables.set(variables.indexOf(tokens[0]), tokens[0]); } else { values.add(value); } break; } else if(tokens[i].charAt(0) == '+') { value = addition(tokens, value); System.out.printf("%5d\n",value); variables.add(tokens[0]); if(map.containsKey(tokens[0])) { values.set(values.indexOf(tokens[0]), value); variables.set(variables.indexOf(tokens[0]), tokens[0]); } else { values.add(value); } break; } else if(i==tokens.length-1 && tokens.length != 3) { System.out.println("No operation"); break; } } map.put(tokens[0], value); } if(Character.isDigit(tokens[0].charAt(0))) { int value = 0; if(tokens.length==1) { System.out.printf("%5s\n", tokens[0]); } else { value = addition(tokens, value); System.out.printf("%5d\n", value); } } if(line.equals("clear")) { clear(map); } if(line.equals("var")) { variableList(variables, values); } } } public static int addition(String[] a, int b) { for(String item : a) { if(Character.isDigit(item.charAt(0))) { int add = Integer.parseInt(item); b = b + add; } } return b; } public static void clear(LinkedHashMap<String,Integer> b) { b.clear(); } public static void variableList(ArrayList<String> a, ArrayList<Integer> b) { for(int i=0; i<a.size(); i++) { System.out.printf("%5s: %d\n", a.get(i), b.get(i)); } } I included the whole code because I'm not sure where the error is arising from.

    Read the article

  • Questions about my program and Polymorphism

    - by Strobe_
    Ok, so basically I'm creating a program which allows the user to select a shape (triangle, square, circle) and then it takes in a int and calculates the boundary length and area. I have no problem doing this and have a program that's working perfectly. (https://gist.github.com/anonymous/c63a03c129560a7b7434 4 classes) But now I have to implement this with polymorphism concepts and I'm honestly struggling as to how to do it. I have a basic idea of what I want to do when it comes to inheritance Main | Shapes / | \ triangle circle square But I don't understand how I'm supposed to override when all the methods within the triangle/square/circle classes are unique, there are no "abstract" methods as such that I could inherit from the "Shapes" class. If somebody could make look quickly at the code I linked and suggest a way to do this it would be much appreciated. Sorry if I was bad at explaining this. Thanks.

    Read the article

  • How to construct query to update nested array document in mongo?

    - by GowtGM
    I am having following document in mongo, { "_id" : ObjectId("506e9e54a4e8f51423679428"), "description" : "ffffffffffffffff", "menus" : [ { "_id" : ObjectId("506e9e5aa4e8f51423679429"), "description" : "ffffffffffffffffffff", "items" : [ { "name" : "xcvxc", "description" : "vxvxcvxc", "text" : "vxcvxcvx", "menuKey" : "0", "onSelect" : "1", "_id" : ObjectId("506e9f07a4e8f5142367942f") } , { "name" : "abcd", "description" : "qqq", "text" : "qqq", "menuKey" : "0", "onSelect" : "3", "_id" : ObjectId("507e9f07a4e8f5142367942f") } ] }, { "_id" : ObjectId("506e9e5aa4e8f51423679429"), "description" : "rrrrr", "items" : [ { "name" : "xcc", "description" : "vx", "text" : "vxc", "menuKey" : "0", "onSelect" : "2", "_id" : ObjectId("506e9f07a4e8f5142367942f") } ] } ] } Now , i want to update the following document : { "name" : "abcd", "description" : "qqq", "text" : "qqq", "menuKey" : "0", "onSelect" : "3", "_id" : ObjectId("507e9f07a4e8f5142367942f") } I am having main documnet id: "_id" : ObjectId("506e9e54a4e8f51423679428") and menus id "_id" : ObjectId("506e9e54a4e8f51423679428") as well as items id "_id" : ObjectId("507e9f07a4e8f5142367942f") which is to be updated. I have tried using the following query: db.collection.update({ "_id" : { "$oid" : "506e9e54a4e8f51423679428"} , "menus._id" : { "$oid" : "506e9e5aa4e8f51423679429"}},{ "$set" : { "menus.$.items" : { "_id" : { "$oid" : "506e9f07a4e8f5142367942f"}} , "menus.$.items.$.name" : "xcvxc66666", ...}},false,false); but its not working...

    Read the article

  • How to re-order a List<String>

    - by tarka
    I have created the following method: public List<String> listAll() { List worldCountriesByLocal = new ArrayList(); for (Locale locale : Locale.getAvailableLocales()) { final String isoCountry = locale.getDisplayCountry(); if (isoCountry.length() > 0) { worldCountriesByLocal.add(isoCountry); Collections.sort(worldCountriesByLocal); } } return worldCountriesByLocal; } Its pretty simple and it returns a list of world countries in the users locale. I then sort it to get it alphabetic. This all works perfectly (except I seem to occasionally get duplicates of countries!). Anyway, what I need is to place the US, and UK at the top of the list regardless. The problem I have is that I can't isolate the index or the string that will be returned for the US and UK because that is specific to the locale! Any ideas would be really appreciated.

    Read the article

  • Linking Apache to Tomcat with multiple domains.

    - by Royce Thigpen
    Okay, so I've been working for a while on this, and have been searching, but so far I have not found any answers that actually answer what I want to know. I'm a little bit at the end of my rope with this one, but I'm hoping I can figure this out sometime soon. So I have Apache 2 installed and serving up standard webpages, but I also have that linked to a Tomcat instance for one of my domains currently supported. However, I want to add another domain to the server via Apache that points to a separate code base from the one I already have. I have been coming at this from several different angles, and I have determined that I just don't know enough about setting up these servers to really do what I want to do. Little information on my server: Currently running a single Tomcat5.5 instance with Apache 2, using mod_jk to connect them together. I have a worker in workers.properties that points it's "host" field to "localhost" with the correct port my Tomcat instance, so that all works. In my Tomcat server.xml file, I have a host defined as "localhost" that points at my webapp that I am currently serving up, with that host set as the defaultHost as well. One thought I had was that I could add a new worker with a different host than "localhost" (i.e. host2) and then define a new host in my server.xml file called "host2" to match it, but after reading around some on the internet, It seems the "host" of the worker must point to a server, and not a hostname in the Tomcat instance, is this correct? Again, a simple rundown of what I want: Setup in apache/tomcat combo such that www.domain1.com points at "webapp1" and www.domain2.com points at "webapp2".

    Read the article

  • ANDROID : how to get value stored in ArrayList<HashMap<key,value>>?

    - by Roshni Kyada
    I have ArrayList. At another activity i want to access all values stored in ArrayList. I tried following code. ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>(); for(Hashmap<String, String> map: mylist) { for(Entry<String, String> mapEntry: map) { String key = mapEntry.getKey(); String value = mapEntry.getValue(); } } but it shows an error at for(Entry mapEntry: map) that it only interate over Array.

    Read the article

  • Android - Parsing XML with XPath

    - by Ruben Deig Ramos
    First of all, thanks to all the people who's going to spend a little time on this question. Second, sorry for my english (not my first language! :D). Well, here is my problem. I'm learning Android and I'm making an app which uses a XML file to store some info. I have no problem creating the file, but trying to read de XML tags with XPath (DOM, XMLPullParser, etc. only gave me problems) I've been able to read, at least, the first one. Let's see the code. Here is the XML file the app generates: <dispositivo> <id>111</id> <nombre>Name</nombre> <intervalo>300</intervalo> </dispositivo> And here is the function which reads the XML file: private void leerXML() { try { XPathFactory factory=XPathFactory.newInstance(); XPath xPath=factory.newXPath(); // Introducimos XML en memoria File xmlDocument = new File("/data/data/com.example.gps/files/devloc_cfg.xml"); InputSource inputSource = new InputSource(new FileInputStream(xmlDocument)); // Definimos expresiones para encontrar valor. XPathExpression tag_id = xPath.compile("/dispositivo/id"); String valor_id = tag_id.evaluate(inputSource); id=valor_id; XPathExpression tag_nombre = xPath.compile("/dispositivo/nombre"); String valor_nombre = tag_nombre.evaluate(inputSource); nombre=valor_nombre; } catch (Exception e) { e.printStackTrace(); } } The app gets correctly the id value and shows it on the screen ("id" and "nombre" variables are assigned to a TextView each one), but the "nombre" is not working. What should I change? :) Thanks for all your time and help. This site is quite helpful! PD: I've been searching for a response on the whole site but didn't found any.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 849 850 851 852 853 854 855 856 857 858 859 860  | Next Page >