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  • Does table columns increase select statement execution time

    - by paokg4
    I have 2 tables, same structure, same rows, same data but the first has more columns (fields). For example: I select the same 3 fields from both of them (SELECT a,b,c FROM mytable1 and then SELECT a,b,c FROM mytable2) I've tried to run those queries on 100,000 records (for each table) but at the end I got the same execution time (0.0006 sec) Do you know if the number of the columns (and in the end the size of the one table is bigger than the other) has to do something with the query execution time?

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  • Java homework help, Error <identifier> expected

    - by user2900126
    Help with java homework this is my assignment that I have, this assignment code I've tried. But when I try to compile it I keep getting errors which I cant seem to find soloutions too: Error says <identifier> expected for Line 67 public static void () Assignment brief To write a simple java classMobile that models a mobile phone. Details the information stored about each mobile phone will include • Its type e.g. “Sony ericsson x90” or “Samsung Galaxy S”; • Its screen size in inches; You may assume that this a whole number from the scale 3 to 5 inclusive. • Its memory card capacity in gigabytes You may assume that this a whole number • The name of its present service provider You may assume this is a single line of text. • The type of contract with service provider You may assume this is a single line of text. • Its camera resolution in megapixels; You should not assume that this a whole number; • The percentage of charge left on the phone e.g. a fully charged phone will have a charge of 100. You may assume that this a whole number • Whether the phone has GPS or not. Your class will have fields corresponding to these attributes . Start by opening BlueJ, creating a new project called myMobile which has a classMobile and set up the fields that you need, Next you will need to write a Constructor for the class. Assume that each phone is manufactured by creating an object and specifying its type, its screen size, its memory card capacity, its camera resolution and whether it has GPS or not. Therefore you will need a constructor that allows you to pass arguments to initialise these five attributes. Other fields should be set to appropriate default values. You may assume that a new phone comes fully charged. When the phone is sold to its owner, you will need to set the service provider and type of contract with that provider so you will need mutator methods • setProvider () - - to set service provider. • setContractType - - to set the type of contract These methods will be used when the phones provider is changed. You should also write a mutator method ChargeUp () which simulates fully charging the phone. To obtain information about your mobile object you should write • accessor methods corresponding to four of its fields: • getType () – which returns the type of mobile; • getProvider () – which returns the present service provider; • getContractType () – which returns its type of contract; • getCharge () – which returns its remaining charge. An accessor method to printDetails () to print, to the terminal window, a report about the phone e.g. This mobile phone is a sony Erricsson X90 with Service provider BigAl and type of contract PAYG. At present it has 30% of its battery charge remaining. Check that the new method works correctly by for example, • creating a Mobile object and setting its fields; • calling printDetails () and t=checking the report corresponds to the details you have just given the mobile; • changing the service provider and contract type by calling setprovider () and setContractType (); • calling printDetails () and checking the report now prints out the new details. Challenging excercises • write a mutator methodswitchedOnFor () =which simulates using the phone for a specified period. You may assume the phone loses 1% of its charge for each hour that it is switched on . • write an accessor method checkcharge () whichg checks the phone remaing charge. If this charge has a value less than 25%, then this method returns a string containg the message Be aware that you will soon need to re-charge your phone, otherwise it returns a string your phone charge is sufficient. • Write a method changeProvider () which simulates changing the provider (and presumably also the type of service contract). Finally you may add up to four additional fields, with appropriate methods, that might be required in a more detailed model. above is my assignment that I have, this assignment code I've tried. But when I try to oompile it I keep getting errors which I cant seem to find soloutions too: Error says <identifier> expected for Line 67 public static void () /** * to write a simple java class Mobile that models a mobile phone. * * @author (Lewis Burte-Clarke) * @version (14/10/13) */ public class Mobile { // type of phone private String phonetype; // size of screen in inches private int screensize; // menory card capacity private int memorycardcapacity; // name of present service provider private String serviceprovider; // type of contract with service provider private int typeofcontract; // camera resolution in megapixels private int cameraresolution; // the percentage of charge left on the phone private int checkcharge; // wether the phone has GPS or not private String GPS; // instance variables - replace the example below with your own private int x; // The constructor method public Mobile(String mobilephonetype, int mobilescreensize, int mobilememorycardcapacity,int mobilecameraresolution,String mobileGPS, String newserviceprovider) { this.phonetype = mobilephonetype; this.screensize = mobilescreensize; this.memorycardcapacity = mobilememorycardcapacity; this.cameraresolution = mobilecameraresolution; this.GPS = mobileGPS; // you do not use this ones during instantiation,you can remove them if you do not need or assign them some default values //this.serviceprovider = newserviceprovider; //this.typeofcontract = 12; //this.checkcharge = checkcharge; Mobile samsungPhone = new Mobile("Samsung", "1024", "2", "verizon", "8", "GPS"); 1024 = screensize; 2 = memorycardcapacity; 8 = resolution; GPS = gps; "verizon"=serviceprovider; //typeofcontract = 12; //checkcharge = checkcharge; } // A method to display the state of the object to the screen public void displayMobileDetails() { System.out.println("phonetype: " + phonetype); System.out.println("screensize: " + screensize); System.out.println("memorycardcapacity: " + memorycardcapacity); System.out.println("cameraresolution: " + cameraresolution); System.out.println("GPS: " + GPS); System.out.println("serviceprovider: " + serviceprovider); System.out.println("typeofcontract: " + typeofcontract); } /** * The mymobile class implements an application that * simply displays "new Mobile!" to the standard output. */ public class mymobile { public static void main(String[] args) { System.out.println("new Mobile!"); //Display the string. } } public static void buildPhones(){ Mobile Samsung = new Mobile("Samsung", "3.0", "4gb", "8mega pixels", "GPS"); Mobile Blackberry = new Mobile("Blackberry", "3.0", "4gb", "8mega pixels", "GPS"); Samsung.displayMobileDetails(); Blackberry.displayMobileDetails(); } public static void main(String[] args) { buildPhones(); } } any answers.replies and help would be greatly appreciated as I really lost!

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  • How do I access the enumerated item with an indexer and assign array string to it for display?

    - by g00p3k
    EDITED: Updated 3/23/09. See rest of post at bottom. I'm still having trouble with the indexer. Anymore help or examples would really help me out. Write a class, MyCourses, that contains an enumeration of all the courses that you are currently taking. This enum should be nested inside of your class MyCourses. Your class should also have an array field that provides a short description (as a String) of each of your courses. Write an indexer that takes one of your enumerated courses as an index and returns the String description of the course. Write a class MyFriends that contains an indexer that provides access to the names of your friends. namespace IT274_Unit4Project { public class MyCourses { // enumeration that contains an enumeration of all the courses that // student is currently enrolled in public enum CourseName {IT274= 0,CS210 = 1} // array field that provides short description for each of classes, // returns string description of the course private String[] courseDescription = {"Intermediate C#: Teaches intermediate elements of C# programming and software design", "Career Development Strategies: Teaches principles for career progression, resume preparation, and overall self anaylsis"}; // indexer that takes one of the enumerated courses as an index // and returns the String description of the course public String this[CourseName index] { get { if (index == 1) return courseDescription[0]; else return courseDescription[1]; } set { if (index == 1) courseDescription[0] = value; else courseDescription[1] = value; } } } }//end public class MyCourses I'm working on this homework project and having trouble understanding the text explaining how to correctly take the accessed value of the enumeration and then apply the string array value to it. Can you please help me understand this? The text we are using is very difficult and poorly written for a beginner to understand, so I'm kind of on my own here. I've got the first parts written, but need some help on the accessing of the enumeration value and assigning, i think i'm close, but don't understand how to properly get and set the values on this. Please do not provide me with direct code answers, unless a MSDN style explanation that is generalized and not specific to my project. ie: public class MyClass { string field1; string field2; //properties public string Value1 get etc... Thanks!

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  • Qt, can't display child widget

    - by Blin
    I have two widgets defined as follows class mainWindow : public QWidget { Q_OBJECT public: mainWindow(); void readConfig(); private: SWindow *config; QVector <QString> filePath; QVector <QLabel*> alias,procStatus; QVector <int> delay; QGridLayout *mainLayout; QVector<QPushButton*> stopButton,restartButton; QVector<QProcess*> proc; QSignalMapper *stateSignalMapper, *stopSignalMapper, *restartSignalMapper; public slots: void openSettings(); void startRunning(); void statusChange(int); void stopProc(int); void restartProc(int); void renew(); }; class SWindow : public QWidget { Q_OBJECT public: SWindow(QWidget *parent=0); void readConfig(); void addLine(int); private: QVector<QPushButton*> selectButton; QVector<QLabel*> filePath; QVector<QLineEdit*> alias; QSignalMapper *selectSignalMapper; QVector<QSpinBox*> delay; QGridLayout *mainLayout; public slots: void selectFile(int); void saveFile(); void addLineSlot(); }; when i create and display SWindow object from mainWindow like this void mainWindow::openSettings() { config = new SWindow(); config->show(); } everything is ok, but now i need to access the mainWindow from SWindow, and void mainWindow::openSettings() { config = new SWindow(this); config->show(); } doesn't display SWindow. How can i display SWindow? How do i call a function on widget close?

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  • Can I set a PHP class property from an existing variable?

    - by jasondavis
    I am trying to figure out how I want to handle settings in my PHP app. I have pretty much decide that I would like to use a Confg class file so it will be autoloaded and flexible in the future. Below is some stuff I was playing with. I know you cannot set a variable to popluate a Constant so I then try to use a public static property. Why can I not set public static $ip = $_SERVER['REMOTE_ADDR']; ?? <?php // config.class.php class Config { const URL = 'http://www.foo.com'; const DB_User = 'dbname'; public static $test = 'test string'; public static $ip = $_SERVER['REMOTE_ADDR']; } /////////////////////////////////////////////////////// //index.php // works echo Config::URL; // works echo Config::$test; // DOES NOT WORK echo Config::$ip; ?>

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  • ASP.NET MVC 2 Preview 2 Route Request Not Working

    - by Kezzer
    Here's the error: The incoming request does not match any route. Basically I upgraded from Preview 1 to Preview 2 and got rid of a load of redundant stuff in relation to areas (as described by Phil Haack). It didn't work so I created a brand new project to check out how its dealt with in Preview 2. The file Default.aspx no longer exists which contains the following: public void Page_Load(object sender, System.EventArgs e) { // Change the current path so that the Routing handler can correctly interpret // the request, then restore the original path so that the OutputCache module // can correctly process the response (if caching is enabled). string originalPath = Request.Path; HttpContext.Current.RewritePath(Request.ApplicationPath, false); IHttpHandler httpHandler = new MvcHttpHandler(); httpHandler.ProcessRequest(HttpContext.Current); HttpContext.Current.RewritePath(originalPath, false); } The error I received points to the line httpHandler.ProcessRequest(HttpContext.Current); yet in newer projects none of this even exists. To test it, I quickly deleted Default.aspx but then absolutely nothing worked, I didn't even receive any errors. Here's some code extracts: Global.asax.cs using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Routing; namespace Intranet { public class MvcApplication : System.Web.HttpApplication { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); AreaRegistration.RegisterAllAreas(); routes.MapRoute( "Default", "{controller}/{action}/{id}", new { controller = "Home", action = "Index", id = "" } ); } protected void App_Start() { RegisterRoutes(RouteTable.Routes); } } } Notice the area registration as that's what I'm using. Routes.cs using System.Web.Mvc; namespace Intranet.Areas.Accounts { public class Routes : AreaRegistration { public override string AreaName { get { return "Accounts"; } } public override void RegisterArea(AreaRegistrationContext context) { context.MapRoute("Accounts_Default", "Accounts/{controller}/{action}/{id}", new { controller = "Home", action = "Index", id = "" }); } } } Check the latest docs for more info on this part. It's to register the area. The Routes.cs files are located in the root folder of each area. Cheers

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  • Object as itemValue in <f:selectItems>

    - by Ehsun
    Is it possible to have objects as itemValue in tag? for example I have a class Foo: public class Foo { private int id; private String name; private Date date; } And another class Bar public class Bar { private Foo foos; } public class BarBean { private Set<Foo> foos; } Now in a Bean called BarBean I need to have a to get the Foo of the current Bar from User like this: <h:selectOneMenu value="#{barBean.bar.foo}" required="true"> <f:selectItems value="#{barBean.foos}" var="foo" itemLabel="#{foo.name}" itemValue="#{foo}" /> </h:selectOneMenu> ---------------edited: my converter: package ir.khorasancustoms.g2g.converters; import ir.khorasancustoms.g2g.persistance.CatalogValue; import java.util.ResourceBundle; import javax.faces.application.FacesMessage; import javax.faces.component.UIComponent; import javax.faces.context.FacesContext; import javax.faces.convert.Converter; import javax.faces.convert.FacesConverter; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; @FacesConverter("ir.khorasancustoms.CatalogValueConverter") public class CatalogValueConverter implements Converter { @Override public Object getAsObject(FacesContext context, UIComponent component, String value) { SessionFactory factory = new Configuration().configure().buildSessionFactory(); Session session = factory.openSession(); try { int id = Integer.parseInt(value); CatalogValue catalogValue = (CatalogValue) session.load(CatalogValue .class, id); return catalogValue; } catch (Exception ex) { Transaction tx = session.getTransaction(); if (tx.isActive()) { tx.rollback(); } ResourceBundle rb = ResourceBundle.getBundle("application"); String message = rb.getString("databaseConnectionFailed"); FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_FATAL, message, message)); } finally { session.close(); } return null; } @Override public String getAsString(FacesContext context, UIComponent component, Object value) { return ((CatalogValue) value).getId() + ""; } } and my facelet: <h:outputText value="#{lbls.paymentUnit}:"/> <h:selectOneMenu id="paymentUnit" label="#{lbls.paymentUnit}" value="#{price.price.ctvUnit}" required="true"> <f:selectItems value="#{price.paymentUnits}"/> <f:converter converterId="ir.khorasancustoms.CatalogValueConverter"/> </h:selectOneMenu> <h:message for="paymentUnit" infoClass="info" errorClass="error" warnClass="warning" fatalClass="fatal"/>

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  • What's the best way to implement a dynamic proxy in C#?

    - by gap
    Hi, I've got a need to create a dynamic proxy in C#. I want this class to wrap another class, and take on it's public interface, forwarding calls for those functions: class MyRootClass { public virtual void Foo() { Console.Out.WriteLine("Foo!"); } } interface ISecondaryInterface { void Bar(); } class Wrapper<T> : ISecondaryInterface where T: MyRootClass { public Wrapper(T otherObj) { } public void Bar() { Console.Out.WriteLine("Bar!"); } } Here's how I want to use it: Wrapper<MyRootClass> wrappedObj = new Wrapper<MyRootClass>(new MyRootClass()); wrappedObj.Bar(); wrappedObj.Foo(); to produce: Bar! Foo! Any ideas? What's the easiest way to do this? What's the best way to do this? Thanks so much.

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  • SQL clone record with a unique index

    - by Milhous
    Is there a clean way of cloning a record in SQL that has an index(auto increment). I want to clone all the fields except the index. I currently have to enumerate every field, and use that in an insert select, and I would rather not explicitly list all of the fields, as they may change over time.

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  • Changing type of object in a conditional

    - by David Doria
    I'm having a bit of trouble with dynamic_casting. I need to determine at runtime the type of an object. Here is a demo: include include class PersonClass { public: std::string Name; virtual void test(){}; //it is annoying that this has to be here... }; class LawyerClass : public PersonClass { public: void GoToCourt(){}; }; class DoctorClass : public PersonClass { public: void GoToSurgery(){}; }; int main(int argc, char *argv[]) { PersonClass* person = new PersonClass; if(true) { person = dynamic_cast(person); } else { person = dynamic_cast(person); } person-GoToCourt(); return 0; } I would like to do the above. The only legal way I found to do it is to define all of the objects before hand: PersonClass* person = new PersonClass; LawyerClass* lawyer; DoctorClass* doctor; if(true) { lawyer = dynamic_cast(person); } else { doctor = dynamic_cast(person); } if(true) { lawyer-GoToCourt(); } The main problem with this (besides having to define a bunch of objects that won't be use) is that I have to change the name of the 'person' variable. Is there a better way? (I am not allowed to change any of the classes (Person, Lawyer, or Doctor) because they are part of a library that people who will use my code have and won't want to change). Thanks, Dave

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  • What is the explanation of this results in Java ?

    - by M.H
    I have the following code : public class Main { private int i = j; //1 private int j = 10; public static void main(String[] args) { System.out.println((new Main()).i); } } and there is a compiler error in line 1 because an illegal forward reference. But when I am trying the following code : public class Main { int i = getJ(); //1 int getJ(){ return j; } int j=10; public static void main(String[] args) { System.out.println(new Main().i); } } it works fine and the result is 0.Why there is no illegal forward reference in line 1 here?.The two codes look similar to me.

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  • unresolved token/symbol in MC++ wrapper class calling native code

    - by rediVider
    I'm new to MC++ and have basically no idea what's going on yet. In trying to get this working i've determined many things that don't work, i'm just looking for one of the ways that will work. I have a mc++ class as follows that seems to have to be a "ref" class to allow me to see any methods/properties. public ref class EmCeePlusPlus { static void Open(void) { Testor* t = new Testor(); Testor::Open(); }; }; extern public class Testor { public: Testor() { }; static void Open(void) { int x = 3; int xx = cli_lock(x); }; }; Now, the only reason i created the class Testor, and moved the call to cli_open to it, is because i was getting a unresolved external symbol if i put the same call in the ref class. In this current code, however, I get an uresolved token error and unresolved symbol error ONLY if i have the call to Testor::Open(). If that line is commented then it compiles fine. As it is I get the errors below. cli_lock() is native code that is able to be called externally by other native DLLs with not problems. Any ideas where i should be looking? error LNK2028: unresolved token (0A000056) "extern "C" int __cdecl cli_lock(int)" (?cli_lock@@$$J0YAHH@Z) referenced in function "public: static void __cdecl Giga::Testor::Open(void)" (?Open@Testor@Giga@@$$FSAXXZ) error LNK2019: unresolved external symbol "extern "C" int __cdecl cli_lock(int)" (?cli_lock@@$$J0YAHH@Z) referenced in function "public: static void __cdecl Giga::Testor::Open(void)" (?Open@Testor@Giga@@$$FSAXXZ)

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  • Does Interlocked guarantee visibility to other threads in C# or do I still have to use volatile?

    - by Lirik
    I've been reading the answer to a similar question, but I'm still a little confused... Abel had a great answer, but this is the part that I'm unsure about: ...declaring a variable volatile makes it volatile for every single access. It is impossible to force this behavior any other way, hence volatile cannot be replaced with Interlocked. This is needed in scenarios where other libraries, interfaces or hardware can access your variable and update it anytime, or need the most recent version. Does Interlocked guarantee visibility of the atomic operation to all threads, or do I still have to use the volatile keyword on the value in order to guarantee visibility of the change? Here is my example: public class CountDownLatch { private volatile int m_remain; // <--- do I need the volatile keyword there since I'm using Interlocked? private EventWaitHandle m_event; public CountDownLatch (int count) { Reset(count); } public void Reset(int count) { if (count < 0) throw new ArgumentOutOfRangeException(); m_remain = count; m_event = new ManualResetEvent(false); if (m_remain == 0) { m_event.Set(); } } public void Signal() { // The last thread to signal also sets the event. if (Interlocked.Decrement(ref m_remain) == 0) m_event.Set(); } public void Wait() { m_event.WaitOne(); } }

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  • .NET port with Java's Map, Set, HashMap

    - by Nikos Baxevanis
    I am porting Java code in .NET and I am stuck in the following lines that (behave unexpectedly in .NET). Java: Map<Set<State>, Set<State>> sets = new HashMap<Set<State>, Set<State>>(); Set<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { ... } The equivalent .NET code could possibly be: IDictionary<HashSet<State>, HashSet<State>> sets = new Dictionary<HashSet<State>, HashSet<State>>(); HashSet<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { /* (Add to a list). Always get here in .NET (??) */ } However the code comparison fails, the program think that "sets" never contain Key "p" and eventually results in OutOfMemoryException. Perhaps I am missing something, object equality and identity might be different between Java and .NET. I tried implementing IComparable and IEquatable in class State but the results were the same. Edit: What the code does is: If the sets does not contain key "p" (which is a HashSet) it is going to add "p" at the end of a LinkedList. The State class (Java) is a simple class defined as: public class State implements Comparable<State> { boolean accept; Set<Transition> transitions; int number; int id; static int next_id; public State() { resetTransitions(); id = next_id++; } // ... public int compareTo(State s) { return s.id - id; } public boolean equals(Object obj) { return super.equals(obj); } public int hashCode() { return super.hashCode(); }

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  • How do I alias the scala setter method 'myvar_$eq(myval)' to something more pleasing when in java?

    - by feydr
    I've been converting some code from java to scala lately trying to teach myself the language. Suppose we have this scala class: class Person() { var name:String = "joebob" } Now I want to access it from java so I can't use dot-notation like I would if I was in scala. So I can get my var's contents by issuing: person = Person.new(); System.out.println(person.name()); and set it via: person = Person.new(); person.name_$eq("sallysue"); System.out.println(person.name()); This holds true cause our Person Class looks like this in javap: Compiled from "Person.scala" public class Person extends java.lang.Object implements scala.ScalaObject{ public Person(); public void name_$eq(java.lang.String); public java.lang.String name(); public int $tag() throws java.rmi.RemoteException; } Yes, I could write my own getters/setters but I hate filling classes up with that and it doesn't make a ton of sense considering I already have them -- I just want to alias the _$eq method better. (This actually gets worse when you are dealing with stuff like antlr because then you have to escape it and it ends up looking like person.name_\$eq("newname"); Note: I'd much rather have to put up with this rather than fill my classes with more setter methods. So what would you do in this situation?

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  • How to manage lifecycle in a ViewGroup-derived class?

    - by Scott Smith
    I had a bunch of code in an activity that displays a running graph of some external data. As the activity code was getting kind of cluttered, I decided to extract this code and create a GraphView class: public class GraphView extends LinearLayout { public GraphView(Context context, AttributeSet attrs) { super(context, attrs); LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); inflater.inflate(R.layout.graph_view, this, true); } public void start() { // Perform initialization (bindings, timers, etc) here } public void stop() { // Unbind, destroy timers, yadda yadda } . . . } Moving stuff into this new LinearLayout-derived class was simple. But there was some lifecycle management code associated with creating and destroying timers and event listeners used by this graph (I didn't want this thing polling in the background if the activity was paused, for example). Coming from a MS Windows background, I kind of expected to find overridable onCreate() and onDestroy() methods or something similar, but I haven't found anything of the sort in LinearLayout (or any of its inherited members). Having to leave all of this initialization code in the Activity, and then having to pass it into the view seemed like it defeated the original purpose of encapsulating all of this code into a reusable view. I ended up adding two additional public methods to my view: start() and stop(). I make these calls from the activity's onResume() and onPause() methods respectively. This seems to work, but it feels like I'm using duct tape here. Does anyone know how this is typically done? I feel like I'm missing something...

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  • Drupal 6: Group multiple values in tpl.php

    - by Jozzeh
    When using the date and views module, you can specify in views (using row style fields) 'group multiple values'. Which is default on. If you turn it off, you get multiple nodes each with a date. For example: - 24th March ------- node1 - 25th March ------- node1 What I'm trying to figure out is: what if you are not using fields but node as Row style. How do you implement this not-group-multiple-values in your type-node.tpl.php?

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  • Accessing a function of an instance which is in an arraylist

    - by fadeir
    I'm tring to access a function of an instance which is in an arraylist. Is there any way to do that without using the class name of the instance? import java.util.ArrayList; import java.util.List; class apple{ int price; public void myFunction(int iPrice) { price=iPrice; } } class orange{ int price; public void myFunction(int iPrice) { price=iPrice; } } public class main { public static void main(String[] args) { List list= new ArrayList(); //create 3 apple object to list list.add( new apple() ); list.add( new apple() ); list.add( new orange() ); list.get(0).myFunction(1); /* Error: The method myFunction(int) is undefined for the type Object*/ } } I know that;((apple) list.get(0)).myFunction(1); is a way but I'dont want to use any class name while calling the function.

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  • Unlock device, display a text, then lock again

    - by Waza_Be
    For the need of my application, I need to display a message on the screen even if the lockscreen is enabled, then wait 3 seconds, than I have to lock again the phone as I don't want it to make unwanted phone calls in your pockets. First part is easy: if (PreferenceManager.getDefaultSharedPreferences( getBaseContext()).getBoolean("wake", false)) { KeyguardManager kgm = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE); boolean isKeyguardUp = kgm.inKeyguardRestrictedInputMode(); WakeLocker.acquire(ProtoBenService.this); Intent myIntent = new Intent(ProtoBenService.this,LockActivity.class); myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); if (isKeyguardUp) { ProtoBenService.this.startActivity(myIntent); } else Toast.makeText(ProtoBenService.this.getBaseContext(), intention, Toast.LENGTH_LONG).show(); WakeLocker.release(); } With this class: public abstract class WakeLocker { private static PowerManager.WakeLock wakeLock; public static void acquire(Context ctx) { if (wakeLock != null) wakeLock.release(); PowerManager pm = (PowerManager) ctx.getSystemService(Context.POWER_SERVICE); wakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.ON_AFTER_RELEASE, "CobeIm"); wakeLock.acquire(); } public static void release() { if (wakeLock != null) wakeLock.release(); wakeLock = null; } } And the Activity: public class LockActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD); window.addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON); window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); TextView tv = new TextView(this); tv.setText("This is working!"); tv.setTextSize(45); setContentView(tv); Runnable mRunnable; Handler mHandler = new Handler(); mRunnable = new Runnable() { @Override public void run() { LockActivity.this.finish(); } }; mHandler.postDelayed(mRunnable, 3 * 1000); } } So, this is nice, the phone can display my text! The only problem comes when I want to lock again the phone, it seems that locking the phone is protected by the system... Programmatically turning off the screen and locking the phone how to lock the android programatically I think that my users won't understand the Device Admin and won't be able to activate it. Is there any workaround to lock the screen without the Device Admin stuff?

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  • What was your "aha moment" in understanding delegates?

    - by CM90
    Considering the use of delegates in C#, does anyone know if there is a performance advantage or if it is a convenience to the programmer? If we are creating an object that holds a method, it sounds as if that object would be a constant in memory to be called on, instead of loading the method every time it is called. For example, if we look at the following Unity3D-based code: public delegate H MixedTypeDelegate<G, H>(G g) public class MainParent : MonoBehaviour // Most Unity classes inherit from M.B. { public static Vector3 getPosition(GameObject g) { /* GameObject is a Unity class, and Vector3 is a struct from M.B. The "position" component of a GameObject is a Vector3. This method takes the GameObject I pass to it & returns its position. */ return g.transform.position; } public static MixedTypeDelegate<GameObject, Vector3> PositionOf; void Awake( ) // Awake is the first method called in Unity, always. { PositionOf = MixedTypeDelegate<GameObject, Vector3>(getPosition); } } public class GameScript : MainParent { GameObject g = new GameObject( ); Vector3 whereAmI; void Update( ) { // Now I can say: whereAmI = PositionOf(g); // Instead of: whereAmI = getPosition(g); } } . . . But that seems like an extra step - unless there's that extra little thing that it helps. I suppose the most succinct way to ask a second question would be to say: When you had your aha moment in understanding delegates, what was the context/scenario/source? Thank you!

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  • Strange befaviour of spring transaction support for JPA + Hibernate +@Transactional annotation

    - by abovesun
    I found out really strange behavior on relatively simple use case, probably I can't understand it because of not deep knowledges of spring @Transactional nature, but this is quite interesting. I have simple User dao that extends spring JpaDaoSupport class and contains standard save method: @Transactional public User save(User user) { getJpaTemplate().persist(user); return user; } If was working fine until I've add new method to same class: User getSuperUser(), this method should return user with isAdmin == true, and if there is no super user in db, method should create one. Thats how it was looking like: public User createSuperUser() { User admin = null; try { admin = (User) getJpaTemplate().execute(new JpaCallback() { public Object doInJpa(EntityManager em) throws PersistenceException { return em.createQuery("select u from UserImpl u where u.admin = true").getSingleResult(); } }); } catch (EmptyResultDataAccessException ex) { User admin = new User('login', 'password'); admin.setAdmin(true); save(admin); // THIS IS THE POINT WHERE STRANGE THING COMING OUT } return admin; } As you see code is strange forward and I was very confused when found out that no transaction was created and committed on invocation of save(admin) method and no new user wasn't actually created despite @Transactional annotation. In result we have situation: when save() method invokes from outside of UserDAO class - @Transactional annotation counted and user successfully created, but if save() invokes from inside of other method of the same dao class - @Transactional annotation ignored. Here how I was change save() method to force it always create transaction. public User save(User user) { getJpaTemplate().execute(new JpaCallback() { public Object doInJpa(EntityManager em) throws PersistenceException { em.getTransaction().begin(); em.persist(user); em.getTransaction().commit(); return null; } }); return user; } As you see I manually invoke begin and commit. Any ideas?

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  • Using enums in Java across multiple classes

    - by Richard Mar.
    I have the following class: public class Card { public enum Suit { SPACES, HEARTS, DIAMONDS, CLUBS }; public Card(Suit nsuit, int nrank) { suit = nsuit; rank = nrank; } private Suit suit; private int rank; } I want to instantiate it in another class, but that class doesn't understand the Suit enum. Where should I put the enum to make it publicly visible?

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  • C++ iterator and const_iterator problem for own container class

    - by BaCh
    Hi there, I'm writing an own container class and have run into a problem I can't get my head around. Here's the bare-bone sample that shows the problem. It consists of a container class and two test classes: one test class using a std:vector which compiles nicely and the second test class which tries to use my own container class in exact the same way but fails miserably to compile. #include <vector> #include <algorithm> #include <iterator> using namespace std; template <typename T> class MyContainer { public: class iterator { public: typedef iterator self_type; inline iterator() { } }; class const_iterator { public: typedef const_iterator self_type; inline const_iterator() { } }; iterator begin() { return iterator(); } const_iterator begin() const { return const_iterator(); } }; // This one compiles ok, using std::vector class TestClassVector { public: void test() { vector<int>::const_iterator I=myc.begin(); } private: vector<int> myc; }; // this one fails to compile. Why? class TestClassMyContainer { public: void test(){ MyContainer<int>::const_iterator I=myc.begin(); } private: MyContainer<int> myc; }; int main(int argc, char ** argv) { return 0; } gcc tells me: test2.C: In member function ‘void TestClassMyContainer::test()’: test2.C:51: error: conversion from ‘MyContainer::iterator’ to non-scalar type ‘MyContainer::const_iterator’ requested I'm not sure where and why the compiler wants to convert an iterator to a const_iterator for my own class but not for the STL vector class. What am I doing wrong?

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  • PHP & MySQL - saving and looping problems.

    - by R.I.P.coalMINERS
    I'm new to PHP and MySQL I want a user to be able to store multiple names and there meanings in a MySQL database tables named names using PHP I will dynamically create form fields with JQuery every time a user clicks on a link so a user can enter 1 to 1,000,000 different names and there meanings which will be stored in a table called names. Since I asked my last question I figured out how to store my values from my form using the for loop but every time I loop my values when I add one or more dynamic fields the second form field named meaning will not save the value entered also my dynamic form fields keep looping doubling, tripling and so on the entered values into the database it all depends on how many form fields are added dynamically. I was wondering how can I fix these problems? On a side note I replaced the query with echo's to see the values that are being entered. Here is the PHP code. <?php if(isset($_POST['submit'])) { $mysqli = mysqli_connect("localhost", "root", "", "site"); $dbc = mysqli_query($mysqli,"SELECT * FROM names WHERE userID='$userID'"); $name = $_POST['name']; $meaning = $_POST['meaning']; if(isset($name['0']) && mysqli_num_rows($dbc) == 0 && trim($name['0'])!=='' && trim($meaning['0'])!=='') { for($n = 0; $n < count($name); $n++) { for($m = 0; $m < count($meaning); $m++) { echo $name[$n] . '<br />'; echo $meaning[$m] . '<br /><br />'; break; } } } } ?> And here is the HTML code. <form method="post" action="index.php"> <ul> <li><label for="name">Name: </label><input type="text" name="name[]" id="name" /></li> <li><label for="meaning">Meaning: </label><input type="text" name="meaning[]" id="meaning" /></li> <li><input type="submit" name="submit" value="Save" /></li> </ul> </form> If needed I will place the JQuery code.

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