Search Results

Search found 33603 results on 1345 pages for 'java champion stephen chin'.

Page 652/1345 | < Previous Page | 648 649 650 651 652 653 654 655 656 657 658 659  | Next Page >

  • JVM GC demote object to eden space?

    - by Kevin
    I'm guessing this isn't possible...but here goes. My understanding is that eden space is cheaper to collect than old gen space, especially when you start getting into very large heaps. Large heaps tend to come up with long running applications (server apps) and server apps a lot of the time want to use some kind of caches. Caches with some kind of eviction (LRU) tend to defeat some assumptions that GC makes (temporary objects die quickly). So cache evictions end up filling up old gen faster than you'd like and you end up with a more costly old gen collection. Now, it seems like this sort of thing could be avoided if java provided a way to mark a reference as about to die (delete keyword)? The difference between this and c++ is that the use is optional. And calling delete does not actually delete the object, but rather is a hint to the GC that it should demote the object back to Eden space (where it will be more easily collected). I'm guessing this feature doesn't exist, but, why not (is there a reason it's a bad idea)?

    Read the article

  • Lost in dates and timezones

    - by Sebastien
    I'm working on an application that stores conferences with their start and end date. Up until now, I was developing in Belgium and my server is in France, so everything is in the same timezone, no problem. But today, I'm in San Francisco, my server is in France and I noticed I have a bug. I'm setting dates from a Flex client (ActionScript automatically adapts date display according to client local timezone, which is GMT-8 for me today. My server runs on Hibernate and MySQL in France (GMT+1). So when I look at my database using phpMyAdmin, I see a date set to "2010-06-07 00:00:01" but in my Flex client it displays "2010-06-06 15:00:01". Ultimately, what I want is that the dates are displayed in the local timezone of the event, which is the date I set it to. So when I'm in Belgium and I set the start date of an event to be "2010-06-07 00:00:01" I want to retrieve it that way. But I'm lost as to what layer adapts what. Is timezone stored in DATETIME MySQL columns (I can't see it in MySQL)? Does Hibernate to anything to it when it transfers it to java.lang.Date that has Timezone information? And ultimately, what is the best way to solve this mess?

    Read the article

  • Running single test class or group with Surefire and TestNG

    - by Slartibartfast
    I want to run single test class from command line using Maven and TestNG Things that doesn't work: mvn -Dtest=ClassName test I have defined groups in pom.xml, and this class isn't in one of those groups. So it got excluded on those grounds. mvn -Dgroups=skipped-group test mvn -Dsurefire.groups=skipped-group test when config is <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>2.7.1</version> <configuration> <groups>functest</groups> </configuration> </plugin> Parameters work fine in there are no groups defined in pom.xml. Similarly, when surefire is configured with <configuration> <includes> <include>**/*UnitTest.java</include> </includes> </configuration> I can add another test with -Dtest parameter, but cannot add group. In any combination, I can narrow down tests to be executed with groups, but not expand them. What's wrong with my configuration? Is there a way to run a single test or group outside of those defined in pom.xml? Tried on Ubuntu 10.04 with Maven 2.2.1, TestNG 5.14.6 and Surefire 2.7.1

    Read the article

  • Uva's 3n+1 problem

    - by dmindreader
    I'm solving Uva's 3n+1 problem and I don't get why the judge is rejecting my answer. The time limit hasn't been exceeded and the all test cases I've tried have run correctly so far. import java.io.*; public class NewClass{ /** * @param args the command line arguments */ public static void main(String[] args) throws IOException { int maxCounter= 0; int input; int lowerBound; int upperBound; int counter; int numberOfCycles; int maxCycles= 0; int lowerInt; BufferedReader consoleInput = new BufferedReader(new InputStreamReader(System.in)); String line = consoleInput.readLine(); String [] splitted = line.split(" "); lowerBound = Integer.parseInt(splitted[0]); upperBound = Integer.parseInt(splitted[1]); int [] recentlyused = new int[1000001]; if (lowerBound > upperBound ) { int h = upperBound; upperBound = lowerBound; lowerBound = h; } lowerInt = lowerBound; while (lowerBound <= upperBound) { counter = lowerBound; numberOfCycles = 0; if (recentlyused[counter] == 0) { while ( counter != 1 ) { if (recentlyused[counter] != 0) { numberOfCycles = recentlyused[counter] + numberOfCycles; counter = 1; } else { if (counter % 2 == 0) { counter = counter /2; } else { counter = 3*counter + 1; } numberOfCycles++; } } } else { numberOfCycles = recentlyused[counter] + numberOfCycles; counter = 1; } recentlyused[lowerBound] = numberOfCycles; if (numberOfCycles > maxCycles) { maxCycles = numberOfCycles; } lowerBound++; } System.out.println(lowerInt +" "+ upperBound+ " "+ (maxCycles+1)); } }

    Read the article

  • Open source real life license examples: yours or others

    - by donpal
    I'm aware of the usual list of open source licenses, so I'm not even going to list it here. What I'd like to ask is about your open source projects (whether out or planned for the future), and why you're planning to choose a certain license over the other. Basically say I went for X license because I wanted Y and that other license didn't provide it for me. I understand that the language itself can make a difference in the choice of license: interpreted languages like PHP vs. compiled languages like Java. I'm mostly interested in hearing about PHP projects, but of course additional insights are welcome. You may even have chosen that particular language for a licensing reason. Ideally I want to hear answers from people who were involved in the actual project (i.e. your own project), because that usually means you've put some thought into the license yourself and understand the implications of that license. But examples of existing projects that aren't your own are OK. Please just say why you think that license was good/bad for them. But first-hand experience is preferred. Looking forward to hearing some informative input.

    Read the article

  • JVM to ignore certificate name mismatch

    - by Heavy Bytes
    I know there were a lot of questions/answers about how to ignore SSL error in the code. On our dev region dev.domain.tld we have configured a app server over SSL. The certificate that is displayed is for somedev.domain.tld. There is no way to change the certificate, it will always be a domain mismatch. So when I deploy a web-service to https://dev.domain.tld and try to connect/call my webservice I get an exception: Caused by: java.security.cert.CertificateException: No name matching dev.domain.tld found And I have the somedev.domain.tld CERT in my trust store. Now, I saw a lot of samples how to change that in the code (using a Trust Manager that accepts all domains), but how do I specify to the JVM to ignore the domain mismatch when connecting to the server? Is there a -Djavax.net.ssl argument or something? Thank you! UPDATE: Or, since I am using Spring-WS, is there a way to set some property in Spring for that? (WebServiceTemplate) UPDATE I guess I'll have to do use something from Spring Security: http://static.springsource.org/spring-ws/sites/1.5/reference/html/security.html

    Read the article

  • How to get components from a JFrame with a GridLayout?

    - by NlightNfotis
    I have a question about Java and JFrame in particular. Let's say I have a JFrame that I am using with a GridLayout. Supposing that I have added JButtons in the JFrame, how can I gain access to the one I want using it's position (by position, I mean a x and a y, used to define the exact place on the Grid). I have tried several methods, for instance getComponentAt(int x, int y), and have seen that those methods do not work as intended when combined with GridLayout, or at least don't work as intended in my case. So I tried using getComponent(), which seems fine. The latest method, that seems to be on a right track for me is (assuming I have a JFrame with a GridLayout with 7 rows and 7 columns, x as columns, y as rows): public JButton getButtonByXAndY(int x, int y) { return (JButton) this.getContentPane().getComponent((y-1) * 7 + x); } Using the above, say I want to get the JButton at (4, 4), meaning the 25th JButton in the JFrame, I would index through the first 21 buttons at first, and then add 4 more, finally accessing the JButton I want. Problem is this works like that in theory only. Any ideas? P.S sorry for linking to an external website, but stack overflow won't allow me to upload the image, because I do not have the required reputation.

    Read the article

  • Way to store a large dictionary with low memory footprint + fast lookups (on Android)

    - by BobbyJim
    I'm developing an android word game app that needs a large (~250,000 word dictionary) available. I need: reasonably fast look ups e.g. constant time preferable, need to do maybe 200 lookups a second on occasion to solve a word puzzle and maybe 20 lookups within 0.2 second more often to check words the user just spelled. EDIT: Lookups are typically asking "Is in the dictionary?". I'd like to support up to two wildcards in the word as well, but this is easy enough by just generating all possible letters the wildcards could have been and checking the generated words (i.e. 26 * 26 lookups for a word with two wildcards). as it's a mobile app, using as little memory as possible and requiring only a small initial download for the dictionary data is top priority. My first naive attempts used Java's HashMap class, which caused an out of memory exception. I've looked into using the SQL lite databases available on android, but this seems like overkill. What's a good way to do what I need?

    Read the article

  • What is the correct stage to use for Google Guice in production in an application server?

    - by Yishai
    It seems like a strange question (the obvious answer would Production, duh), but if you read the java docs: /** * We want fast startup times at the expense of runtime performance and some up front error * checking. */ DEVELOPMENT, /** * We want to catch errors as early as possible and take performance hits up front. */ PRODUCTION Assuming a scenario where you have a stateless call to an application server, the initial receiving method (or there abouts) creates the injector new every call. If there all of the module bindings are not needed in a given call, then it would seem to have been better to use the Development stage (which is the default) and not take the performance hit upfront, because you may never take it at all, and here the distinction between "upfront" and "runtime performance" is kind of moot, as it is one call. Of course the downside of this would appear to be that you would lose the error checking, causing potential code paths to cause a problem by surprise. So the question boils down to are the assumptions in the above correct? Will you save performance on a large set of modules when the given lifetime of an injector is one call?

    Read the article

  • Android Layout + Programming

    - by MD
    I'm trying to create a "scrollable" layout in Android. Even using developers.android.com, though, I feel a little bit lost at the moment. I'm somewhat new to Java, but not so much that I feel I should be having these issues--being new to Android is the bigger problem right now. The layout I'm trying to create should scroll in a sort of a "grid". I THINK what I'm looking for is the Gallery view, but I'm really lost as to how to implement it at the moment. I want it to "snap" to center the frame, like in the actual Gallery application. Essentially, if I had a photo gallery of 9 pictures, the idea is to scroll between them up/down AND side to side, in a 3x3 manner. Doesn't need to dynamically adjust, or anything like that, I just want a grid I can scroll through. I'm also not asking for anyone to give me explicit code for it--I'm trying to learn, more than anything. But pointing me in the right direction for helpful layout programming resources would be greatly appreciated, and confirming if it's a Gallery view I'm looking for would also be really helpful. Thanks in advance.

    Read the article

  • What is a reasonable OSGi development workflow?

    - by levand
    I'm using OSGi for my latest project at work, and it's pretty beautiful as far as modularity and functionality. But I'm not happy with the development workflow. Eventually, I plan to have 30-50 separate bundles, arranged in a dependency graph - supposedly, this is what OSGi is designed for. But I can't figure out a clean way to manage dependencies at compile time. Example: You have bundles A and B. B depends on packages defined in A. Each bundle is developed as a separate Java project. In order to compile B, A has to be on the javac classpath. Do you: Reference the file system location of project A in B's build script? Build A and throw the jar into B's lib directory? Rely on Eclipse's "referenced projects" feature and always use Eclipse's classpath to build (ugh) Use a common "lib" directory for all projects and dump the bundle jars there after compilation? Set up a bundle repository, parse the manifest from the build script and pull down the required bundles from the repository? No. 5 sounds the cleanest, but also like a lot of overhead.

    Read the article

  • How to display panels with component in frame

    - by terence6
    Why my JFrame 'frame' is diplaying empty window, when it should give me 3 menu buttons and my own painted JComponent below ? What am I missing here ? import java.awt.*; import javax.swing.*; public class Eyes extends JFrame { public static void main(String[] args) { final JFrame frame = new JFrame("Eyes"); frame.setPreferredSize(new Dimension(450, 300)); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel players = new JPanel(new GridLayout(1, 3)); players.add(new JButton("Eyes color")); players.add(new JButton("Eye pupil")); players.add(new JButton("Background color")); JPanel eyes = new JPanel(); eyes.add(new MyComponent()); JPanel content = new JPanel(); content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS)); content.add(players); content.add(eyes); frame.getContentPane(); frame.pack(); frame.setVisible(true); } } class MyComponent extends JComponent { public MyComponent(){ } @Override public void paint(Graphics g) { int height = 120; int width = 120; Graphics2D g2d = (Graphics2D) g; g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON); BasicStroke bs = new BasicStroke(3.0f); g2d.setStroke(bs); g2d.setColor(Color.yellow); g2d.fillOval(200, 200, height, width); g2d.setColor(Color.black); g2d.drawOval(60, 60, height, width); } }

    Read the article

  • What good open source programs exist for fuzzing popular image file types?

    - by JohnnySoftware
    I am looking for a free, open source, portable fuzzing tool for popular image file types that is written in either Java, Python, or Jython. Ideally, it would accept specifications for the fuzzable fields using some kind of declarative constraints. Non-procedural grammar for specifying constraints are greatly preferred. Otherwise, might as well write them all in Python or whatever. Just specifying ranges of valid values or expressions for them. Ideally, it would support some kind of generative programming to export the fuzzer into various programming languages to suit cases where more customization was required. If it supported a direct-manipulation GUI for controlling parameter values and ranges, that would be nice too. The file formats that should be supported are: GIF JPEG PNG So basically, it should be sort of a toolkit consisting of ready-to-run utility, a framework or library, and be capable of generating the fuzzed files directly as well as from programs it generates. It needs to be simple so that test images can be created quickly. It should have a batch capability for creating a series of images. Creating just one at a time would be too painful. I do not want a hacking tool, just a QA tool. Basically, I just want to address concerns that it is taking too long to get commonplace image rendering/parsing libraries stable and trustworthy.

    Read the article

  • Parameterized SPARQL query with JENA

    - by sandra
    I'm trying to build a small semantic web application using Jena framework, JSP and JAVA. I have a remote SPARQL endpoint and I've already written a simple query which works fine but now I need to use some parameters. Here is my code so far: final static String serviceEndpoint = "http://fishdelish.cs.man.ac.uk/sparql/"; String comNameQuery = "PREFIX fd: <http://fishdelish.cs.man.ac.uk/rdf/vocab/resource/> " + "SELECT ?name ?language ?type" + "WHERE { ?nameID fd:comnames_ComName ?name ;" + "fd:comnames_Language ?language ;" + "fd:comnames_NameType ?type ." + "}"; Query query = QueryFactory.create(comNameQuery); QueryExecution qe = QueryExecutionFactory.sparqlService(serviceEndpoint,query); try { ResultSet rs = qe.execSelect(); if ( rs.hasNext() ) { System.out.println(ResultSetFormatter.asText(rs)); } } catch(Exception e) { System.out.println(e.getMessage()); } finally { qe.close(); } What I want to do is to parameterized ?name. I'm new to Jena and I'm not really sure how to use parameters in a SPARQL query. I would appreciate it if someone could help me with this.

    Read the article

  • Within an aray of objects can one create a new instance of an object at an index?

    - by David
    Here's the sample code: class TestAO { int[] x; public TestAO () { this.x = new int[5] ; for (int i = 0; i<x.length; i++) x[i] = i; } public static void main (String[]arg) { TestAO a = new TestAO (); System.out.println (a) ; TestAO c = new TestAO () ; c.x[3] = 35 ; TestAO[] Z = new TestAO[3] ; Z[0] = a ; Z[1] = (TestAO b = new TestAO()) ; Z[2] = c ; } } When i try to compile this i get an error message at the line Z[1] which reads as follows: TestAO.java:22: ')' expected Z[1] = (TestAO b = new TestAO()) ; ^ What i'm trying to do here is create an instance of the object TestAO that i want to be in that index within the assignment of the value at that index instead of creating the instance of the object outside of the array like i did with a. Is this legal and i'm just making some syntax error that i can't see (thus causing the error message) or can what i'm trying to do just not be done?

    Read the article

  • JPA/Hibernate Parent/Child relationship

    - by NubieJ
    Hi I am quite new to JPA/Hibernate (Java in general) so my question is as follows (note, I have searched far and wide and have not come across an answer to this): I have two entities: Parent and Child (naming changed). Parent contains a list of Children and Children refers back to parent. e.g. @Entity public class Parent { @Id @Basic @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "PARENT_ID", insertable = false, updatable = false) private int id; /* ..... */ @OneToMany(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY) @JoinColumn(name = "PARENT_ID", referencedColumnName = "PARENT_ID", nullable = true) private Set<child> children; /* ..... */ } @Entity public class Child { @Id @Basic @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "CHILD_ID", insertable = false, updatable = false) private int id; /* ..... */ @ManyToOne(cascade = { CascadeType.REFRESH }, fetch = FetchType.EAGER, optional = false) @JoinColumn(name = "PARENT_ID", referencedColumnName = "PARENT_ID") private Parent parent; /* ..... */ } I want to be able to do the following: Retrieve a Parent entity which would contain a list of all its children (List), however, when listing Parent (getting List, it of course should omit the children from the results, therefore setting FetchType.LAZY. Retrieve a Child entity which would contain an instance of the Parent entity. Using the code above (or similar) results in two exceptions: Retrieving Parent: A cycle is detected in the object graph. This will cause infinitely deep XML... Retrieving Child: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: xxxxxxxxxxx, no session or session was closed When retrieving the Parent entity, I am using a named query (i.e. calling it specifically) @NamedQuery(name = "Parent.findByParentId", query = "SELECT p FROM Parent AS p LEFT JOIN FETCH p.children where p.id = :id") Code to get Parent (i.e. service layer): public Parent findByParentId(int parentId) { Query query = em.createNamedQuery("Parent.findByParentId"); query.setParameter("id", parentId); return (Parent) query.getSingleResult(); } Why am I getting a LazyInitializationException event though the List property on the Parent entity is set as Lazy (when retrieving the Child entity)?

    Read the article

  • Code Golf: Counting XML elements in file on Android

    - by CSharperWithJava
    Take a simple XML file formatted like this: <Lists> <List> <Note/> ... <Note/> </List> <List> <Note/> ... <Note/> </List> </Lists> Each node has some attributes that actually hold the data of the file. I need a very quick way to count the number of each type of element, (List and Note). Lists is simply the root and doesn't matter. I can do this with a simple string search or something similar, but I need to make this as fast as possible. Design Parameters: Must be in java (Android application). Must AVOID allocating memory as much as possible. Must return the total number of Note elements and the number of List elements in the file, regardless of location in file. Number of Lists will typically be small (1-4), and number of notes can potentially be very large (upwards of 1000, typically 100) per file. I look forward to your suggestions.

    Read the article

  • Connect.registerUsers - Need helping creating array for accounts param

    - by mw_javaguy
    I keep getting the following error when I try to invoke the Facebook REST API Call: Connect.registerUsers Error Code: 100 - param accounts must be an array JSON based response (from Facebook): {"error_code":100,"error_msg":"param accounts must be an array.","request_args": [{"key":"accounts","value":"{email_hash:5232156322_55ddgvc3db5ddcf218049dd564da2x06}"}, {"key":"api_key","value":"23b2c4c6a23445fbffssf8aab96a5e5"}, {"key":"format","value":"JSON"},{"key":"method","value":"Connect.registerUsers"},{"key":"sig","value":"3sd54153a31382fa6e72eecf3c57d7c9"},{"key":"v","value":"1.0"}],"message":"Unknown exception","code":0} I set up the Java code to invoke the REST end point using HttpClient like this: String API_KEY = "23b2c4c6a23445fbffssf8aab96a5e5"; String toConnectRegisterUsersSignature = "accounts=" + "{email_hash:" + emailHash + "}" + "api_key=" + API_KEY + "format=JSON" + "method=Connect.registerUsers" + "v=1.0" + "0c786155bd3cxe8228d924542da5gf2"; String connectRegisterUsersSignature = SimpleMd5.MD5(toConnectRegisterUsersSignature); NameValuePair[] connectRegisterUsersParameters = { new NameValuePair("accounts", "{email_hash:" + emailHash + "}"), new NameValuePair("api_key", API_KEY), new NameValuePair("format", "JSON"), new NameValuePair("method", "Connect.registerUsers"), new NameValuePair("sig", connectRegisterUsersSignature), new NameValuePair("v", "1.0") }; Tried the following combinations and I still get the same error! Signature: "accounts=" + "[email_hash=" + emailHash + "]" new NameValuePair("accounts", "[email_hash=" + emailHash + "]") Signature: "accounts=" + "email_hash[" + emailHash + "]" new NameValuePair("accounts", "email_hash[" + emailHash + "]") Signature: "accounts=" + "email_hash(" + emailHash + ")" new NameValuePair("accounts", "email_hash(" + emailHash + ")") Signature: "accounts=" + "[email_hash=" + emailHash + "]" new NameValuePair("accounts", "[email_hash=" + emailHash + "]") Signature: "accounts=" + "email_hash=" + emailHash new NameValuePair("accounts", "email_hash=" + emailHash) Signature: "accounts=" + "[{email_hash:" + emailHash + "}]" new NameValuePair("accounts", "[{email_hash:" + emailHash + "}]"), Does anyone know how to construct this array that the response is requesting? Happy programming and thank you for taking the time to read this.

    Read the article

  • Quickest way to compare a bunch of array or list of values.

    - by zapping
    Can you please let me know on the quickest and efficient way to compare a large set of values. Its like there are a list of parent codes(string) and each code has a series of child values(string). The child lists have to be compared with each other and find out duplicates and count how many times they repeat. code1(code1_value1, code1_value2, code3_value3, ..., code1_valueN); code2(code2_value1, code1_value2, code2_value3, ..., code2_valueN); code3(code2_value1, code3_value2, code3_value3, ..., code3_valueN); . . . codeN(codeN_value1, codeN_value2, codeN_value3, ..., codeN_valueN); The lists are huge say like there are 100 parent codes and each has about 250 values in them. There will not be duplicates within a code list. Doing it in java and the solution i could figure out is. Store the values of first set of code in as codeMap.put(codeValue, duplicateCount). The count initialized to 0. Then compare the rest of the values with this. If its in the map then increment the count otherwise append it to the map. The downfall of this is to get the duplicates. Another iteration needs to be performed on a very large list. An alternative is to maintain another hashmap for duplicates like duplicateCodeMap.put(codeValue, duplicateCount) and change the initial hashmap to codeMap.put(codeValue, codeValue). Speed is what is requirement. Hope one of you can help me with it.

    Read the article

  • How do I check if a variable has been initialized

    - by Javier Parra
    First of all, I'm fairly new to Java, so sorry if this question is utterly simple. The thing is: I have a String[] s made by splitting a String in which every item is a number. I want to cast the items of s into a int[] n. s[0] contains the number of items that n will hold, effectively s.length-1. I'm trying to do this using a foreach loop: int[] n; for(String num: s){ //if(n is not initialized){ n = new int[(int) num]; continue; } n[n.length] = (int) num; } Now, I realize that I could use something like this: int[] n = new int[(int) s[0]]; for(int i=0; i < s.length; i++){ n[n.length] = (int) s[i]; } But I'm sure that I will be faced with that "if n is not initialized initialize it" problem in the future.

    Read the article

  • Android Signal analysis + some filters.

    - by Profete162
    Hello, as the world cup is the main sport event and the Vuvuzelas are the most annoying sound in the world, I had an idea to remove them definitively by reading this new ( http://www.popsci.com/diy/article/2010-06/simple-software-can-filter-out-vuvuzela-whine) that told us that the sound has some frequencies at 233Hz + 466,932,1864Hz. I have already made a lot of Android application by myself but never touching the signal analysis and filtering part, so here are a few questions, I do not ask for precise answer but maybe links and tutorial to find something to work on. I guess that a new Android phone has the CPU and power to make real-time filtering. 1) How can I intercept the sound coming from the Jack microphone - Line-IN plug- ( I plan to link my TV to my phone with Jack to Jack plug). My question is totally software and coding, I have all the wires and adapters to plug a jack into my android phone Line IN. 2) Are there some Fourier analysis librairies, may I have a look to Java libraries on the web and import them to my Android project? I really apologize because my question seem not precise, but I think that would be something great. Thank you for your answers.

    Read the article

  • Use of 'super' keyword when accessing non-overridden superclass methods

    - by jonny
    I'm trying to get the hang of inheritance in Java and have learnt that when overriding methods (and hiding fields) in sub classes, they can still be accessed from the super class by using the 'super' keyword. What I want to know is, should the 'super' keyword be used for non-overridden methods? Is there any difference (for non-overridden methods / non-hidden fields)? I've put together an example below. public class Vehicle { public int tyreCost; public Vehicle(int tyreCost) { this.tyreCost = tyreCost; } public int getTyreCost() { return tyreCost; } } and public class Car extends Vehicle { public int wheelCount; public Vehicle(int tyreCost, int wheelCount) { super(tyreCost); this.wheelCount = wheelCount; } public int getTotalTyreReplacementCost() { return getTyreCost() * wheelCount; } } Specifically, given that getTyreCost() hasn't been overridden, should getTotalTyreReplacementCost() use getTyreCost(), or super.getTyreCost() ? I'm wondering whether super should be used in all instances where fields or methods of the superclass are accessed (to show in the code that you are accessing the superclass), or only in the overridden/hidden ones (so they stand out).

    Read the article

  • Address family not supported by protocol exception

    - by srg
    I'm trying to send a couple of values from an android application to a web service which I've setup. I'm using Http Post to send them but when I run the application I get the error- request time failed java.net.SocketException: Address family not supported by protocol. I get this while debugging with both the emulator as well as a device connected by wifi. I've already added the internet permission using: <uses-permission android:name="android.permission.INTERNET" /> This is the code i'm using to send the values void insertData(String name, String number) throws Exception { String url = "http://192.168.0.12:8000/testapp/default/call/run/insertdbdata/"; HttpClient client = new DefaultHttpClient(); HttpPost post = new HttpPost(url); try { List<NameValuePair> params = new ArrayList<NameValuePair>(2); params.add(new BasicNameValuePair("a", name)); params.add(new BasicNameValuePair("b", number)); post.setEntity(new UrlEncodedFormEntity(params)); HttpResponse response = client.execute(post); }catch(Exception e){ e.printStackTrace(); } Also I know that my web service work fine because when I send the values from an html page it works fine - <form name="form1" action="http://192.168.0.12:8000/testapp/default/call/run/insertdbdata/" method="post"> <input type="text" name="a"/> <input type="text" name="b"/> <input type="submit"/> I've seen questions of similar problems but haven't really found a solution. Thanks

    Read the article

  • How to implement a network protocol?

    - by gotch4
    Here is a generic question. I'm not in search of the best answer, I'd just like you to express your favourite practices. I want to implement a network protocol in Java (but this is a rather general question, I faced the same issues in C++), this is not the first time, as I have done this before. But I think I am missing a good way to implement it. In fact usually it's all about exchanging text messages and some byte buffers between hosts, storing the status and wait until the next message comes. The problem is that I usually end up with a bunch of switch and more or less complex if statements that react to different statuses / messages. The whole thing usually gets complicated and hard to mantain. Not to mention that sometimes what comes out has some "blind spot", I mean statuses of the protocol that have not been covered and that behave in a unpredictable way. I tried to write down some state machine classes, that take care of checking start and end statuses for each action in more or less smart ways. This makes programming the protocol very complicated as I have to write lines and lines of code to cover every possible situation. What I'd like is something like a good pattern, or a best practice that is used in programming complex protocols, easy to mantain and to extend and very readable. What are your suggestions?

    Read the article

< Previous Page | 648 649 650 651 652 653 654 655 656 657 658 659  | Next Page >