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Search found 1787 results on 72 pages for 'reflection emit'.

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  • Why Use java.lang.reflect.Array For Anything Other Than Array Creation?

    - by dimo414
    Java Class java.lang.reflect.Array provides a set of tools for creating an array dynamically. However in addition to that it has a whole set of methods for accessing (get, set, and length) an array. I don't understand the point of this, since you can (and presumably would) cast your dynamically generated array as an array upon creation, which means you can use the normal array access (bracket notation) functionality. In fact, looking at the source code you can see that is all the class does, cast the array, and throw an exception if the cast fails. So what's the point / usefulness of all of these extra methods?

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  • Mysterious newInstance method

    - by songsungkyun
    First I show some code. library: axis.jar, dom4j.jar jdk1.5, windowsXP T.java import java.io.StringWriter; import org.apache.axis.utils.StringUtils; import org.dom4j.DocumentHelper; import org.dom4j.io.OutputFormat; import org.dom4j.io.XMLWriter; public class T { public T() { System.out.println("constructor"); } public void test() { System.out.println(StringUtils.unescapeNumericChar("1")); } public String getPrettyXML(String xml) throws Exception { System.out.println("getPrettyXML"); StringWriter sw = new StringWriter(); XMLWriter writer = null; try { OutputFormat format = OutputFormat.createPrettyPrint(); org.dom4j.Document document = DocumentHelper.parseText(xml); writer = new XMLWriter(sw, format); writer.write(document); } catch (Exception e) { throw e; } finally { if (writer != null) { try { writer.close(); } catch (Exception e) { } } } return sw.toString(); } public void a() { System.out.println("a"); } public static void main(String[] args) { new T().test(); } } T2.java public class T2 { public static void main(String[] args) throws Exception { System.out.println("T2"); T t = (T) Class.forName("T").newInstance(); } } Ok, here we go... run as (Of course, I'm run at the directory where T.class, T1.class is) java T2 as you can see, not exist class path. ==console== T2 constructor OK... Now delete throw e line at the catch block on the "getPrettyXML" method of T. Ok, here we go.. run one more time without classpath java T2 You can see below... ==console== T2 Exception in thread "main" java.lang.NoClassDefFoundError: org/dom4j/io/OutputFormat at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Unknown Source) at T2.main(T2.java:5) I know that it's not very important for my life or your life. But it's so mysterisou to me, and my all curiosity. thanks.. ^^

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  • How to extract object reference from property access lamda

    - by Jim C
    Here's a follow-up question to http://stackoverflow.com/questions/2820660/get-name-of-property-as-a-string. Given a method Foo (error checking omitted for brevity): // Example usage: Foo(() => SomeClass.SomeProperty) // Example usage: Foo(() => someObject.SomeProperty) void Foo(Expression<Func<T>> propertyLambda) { var me = propertyLambda.Body as MemberExpression; var pi = me.Member as PropertyInfo; bool propertyIsStatic = pi.GetGetMethod().IsStatic; object owner = propertyIsStatic ? me.Member.DeclaringType : ???; ... // Execute property access object value = pi.GetValue(owner, null); } I've got the static property case working but don't know how to get a reference to someObject in the instance property case. Thanks in advance.

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  • How to discover getters and setters on hibernate objects

    - by Michael Jones
    I need to find a way of taking a hibernate object and discovering at runtime all of the getter methods that relate to persistable fields. I'm using annotations in the classes but have previously had difficulties working with them (I ran into a 2 year old bug the java developers still haven't fixed). Does anyone know how I can do this please, ideally without using annotations? Thanks. PS - What I'm trying to do here is to update a new object with values from an existing object dynamically.

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  • Why is my Type.GetFields(BindingFlags.Instance|BindingFlags.Public) not working?

    - by granadaCoder
    My code can see the non-public members, but not the public ones. Why? FieldInfo[] publicFieldInfos = t.GetFields(BindingFlags.Instance | BindingFlags.Public); is returning nothing. Note: I'm trying to get at the properties on the abstract class as well as the concrete class. (And read the attributes as well). The MSDN example works with the 2 flags (BindingFlags.Instance | BindingFlags.Public) but my mini inheritance example below does not. private void RunTest1() { try { textBox1.Text = string.Empty; Type t = typeof(MyInheritedClass); //Look at the BindingFlags *** NonPublic *** int fieldCount = 0; while (null != t) { fieldCount += t.GetFields(BindingFlags.Instance | BindingFlags.NonPublic).Length; FieldInfo[] nonPublicFieldInfos = t.GetFields(BindingFlags.Instance | BindingFlags.NonPublic); foreach (FieldInfo field in nonPublicFieldInfos) { if (null != field) { Console.WriteLine(field.Name); } } t = t.BaseType; } Console.WriteLine("\n\r------------------\n\r"); //Look at the BindingFlags *** Public *** t = typeof(MyInheritedClass); FieldInfo[] publicFieldInfos = t.GetFields(BindingFlags.Instance | BindingFlags.Public); foreach (FieldInfo field in publicFieldInfos) { if (null != field) { Console.WriteLine(field.Name); object[] attributes = field.GetCustomAttributes(t, true); if (attributes != null && attributes.Length > 0) { foreach (Attribute att in attributes) { Console.WriteLine(att.GetType().Name); } } } } } catch (Exception ex) { ReportException(ex); } } private void ReportException(Exception ex) { Exception innerException = ex; while (innerException != null) { Console.WriteLine(innerException.Message + System.Environment.NewLine + innerException.StackTrace + System.Environment.NewLine + System.Environment.NewLine); innerException = innerException.InnerException; } } public abstract class MySuperType { public MySuperType(string st) { this.STString = st; } public string STString { get; set; } public abstract string MyAbstractString { get; set; } } public class MyInheritedClass : MySuperType { public MyInheritedClass(string ic) : base(ic) { this.ICString = ic; } [Description("This is an important property"), Category("HowImportant")] public string ICString { get; set; } private string _oldSchoolPropertyString = string.Empty; public string OldSchoolPropertyString { get { return _oldSchoolPropertyString; } set { _oldSchoolPropertyString = value; } } [Description("This is a not so importarnt property"), Category("HowImportant")] public override string MyAbstractString { get; set; } }

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  • Getting the type of a parametrized class parameter?

    - by GuidoMB
    I have the following class public class MyClass<T> { public Class<T> getDomainClass() { GET THE CLASS OF T } } I've googled this problem and all the answers I could find told me to use getGenericSuperClass(), but the problem of this method is that I must have a second class that extends MyClass and I don't want to do this. What I need is to get the parametrized type of a concrete class?

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  • Getting the type of an array of T, without specifying T - Type.GetType("T[]")

    - by Merlyn Morgan-Graham
    I am trying to create a type that refers to an array of a generic type, without specifying the generic type. That is, I would like to do the equivalent of Type.GetType("T[]"). I already know how to do this with a non-array type. E.g. Type.GetType("System.Collections.Generic.IEnumerable`1") // or typeof(IEnumerable<>) Here's some sample code that reproduces the problem. using System; using System.Collections.Generic; public class Program { public static void SomeFunc<T>(IEnumerable<T> collection) { } public static void SomeArrayFunc<T>(T[] collection) { } static void Main(string[] args) { Action<Type> printType = t => Console.WriteLine(t != null ? t.ToString() : "(null)"); Action<string> printFirstParameterType = methodName => printType( typeof(Program).GetMethod(methodName).GetParameters()[0].ParameterType ); printFirstParameterType("SomeFunc"); printFirstParameterType("SomeArrayFunc"); var iEnumerableT = Type.GetType("System.Collections.Generic.IEnumerable`1"); printType(iEnumerableT); var iEnumerableTFromTypeof = typeof(IEnumerable<>); printType(iEnumerableTFromTypeof); var arrayOfT = Type.GetType("T[]"); printType(arrayOfT); // Prints "(null)" // ... not even sure where to start for typeof(T[]) } } The output is: System.Collections.Generic.IEnumerable`1[T] T[] System.Collections.Generic.IEnumerable`1[T] System.Collections.Generic.IEnumerable`1[T] (null) I'd like to correct that last "(null)". This will be used to get an overload of a function via reflections by specifying the method signature: var someMethod = someType.GetMethod("MethodName", new[] { typeOfArrayOfT }); // ... call someMethod.MakeGenericMethod some time later I've already gotten my code mostly working by filtering the result of GetMethods(), so this is more of an exercise in knowledge and understanding.

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  • Getting set accessor for property in abstract class, not possible?

    - by Lars Udengaard
    Given the class': public abstract class AbstractEntity { public virtual Guid Id { get; private set; } } public class Entity { public virtual Guid Id { get; private set; } } And a PropertyInfo for the property 'Id'. When calling the method: PropertyInfo.GetAccessors() It returns both the get-method and the set-method when the class is not abstract (Entity), but only the get-method when the class is abstract (AbstractEntity). Why is this? And is there another way to get the set-method from a property with a private set?

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  • Magic Method __set() on a Instanciated Object

    - by streetparade
    Ok i have a problem, sorry if i cant explaint it clear but the code speaks for its self. i have a class which generates objects from a given class name; Say we say the class is Modules: public function name($name) { $this->includeModule($name); try { $module = new ReflectionClass($name); $instance = $module->isInstantiable() ? $module->newInstance() : "Err"; $this->addDelegate($instance); } catch(Exception $e) { Modules::Name("Logger")->log($e->getMessage()); } return $this; } The AddDelegate Method: protected function addDelegate($delegate) { $this->aDelegates[] = $delegate; } The __call Method public function __call($methodName, $parameters) { $delegated = false; foreach ($this->aDelegates as $delegate) { if(class_exists(get_class($delegate))) { if(method_exists($delegate,$methodName)) { $method = new ReflectionMethod(get_class($delegate), $methodName); $function = array($delegate, $methodName); return call_user_func_array($function, $parameters); } } } The __get Method public function __get($property) { foreach($this->aDelegates as $delegate) { if ($delegate->$property !== false) { return $delegate->$property; } } } All this works fine expect the function __set public function __set($property,$value) { //print_r($this->aDelegates); foreach($this->aDelegates as $k=>$delegate) { //print_r($k); //print_r($delegate); if (property_exists($delegate, $property)) { $delegate->$property = $value; } } //$this->addDelegate($delegate); print_r($this->aDelegates); } class tester { public function __set($name,$value) { self::$module->name(self::$name)->__set($name,$value); } } Module::test("logger")->log("test"); // this logs, it works echo Module::test("logger")->path; //prints /home/bla/test/ this is also correct But i cant set any value to class log like this Module::tester("logger")->path ="/home/bla/test/log/"; The path property of class logger is public so its not a problem of protected or private property access. How can i solve this issue? I hope i could explain my problem clear.

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  • C# eval equivalent?

    - by Adhip Gupta
    I can do an eval("something()"); to execute the code dynamically in JavaScript. Is there a way for me to do the same thing in C#? What I am exactly trying to do is that I have an integer variable (say i) and I have multiple properties by the names: "Property1","Property2","Property3" etc. Now, I want to perform some operations on the " Propertyi " property depending on the value of i. This is really simple with Javascript. Is there any way to do this with C#? Edit: Oh, and I am using C# 2.0

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  • Fast check if an object will be successfully instantiated in PHP?

    - by Gremo
    How can I check if an object will be successfully instantiated with the given argument, without actually creating the instance? Actually I'm only checking (didn't tested this code, but should work fine...) the number of required parameters, ignoring types: // Filter definition and arguments as per configuration $filter = $container->getDefinition($serviceId); $args = $activeFilters[$filterName]; // Check number of required arguments vs arguments in config $constructor = $reflector->getConstructor(); $numRequired = $constructor->getNumberOfRequiredParameters(); $numSpecified = is_array($args) ? count($args) : 1; if($numRequired < $numSpecified) { throw new InvalidFilterDefinitionException( $serviceId, $numRequired, $numSpecified ); }

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  • Get derived class type from a base's class static method

    - by Marco Bettiolo
    Hi, i would like to get the type of the derived class from a static method of its base class. How can this be accomplished? Thanks! class BaseClass { static void Ping () { Type t = this.GetType(); // should be DerivedClass, but it is not possible with a static method } } class DerivedClass : BaseClass {} // somewhere in the code DerivedClass.Ping();

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  • How to tell Reflectively if an Attribute has a public Setter

    - by DrLazer
    Im saving an object model out to XML but when i load it back in I get exceptions when trying to use PropertyInfo.SetValue() because the property doesn't have a setter just a getter. I want to either not save out the properties that only have getters or figure out on load whether its valid for me to try and set a value or not. Anybody know how to do this Cheers

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  • C#, get all collection properties from an object

    - by Eatdoku
    Hi, I have a class with 3 List collections like the following. I am trying to have a logic which will iterate through the object's "collection" properties and do some operation using the data stored in those collections. I am just wondering if there is an easy way of doing it using foreach. thanks public class SampleChartData { public List<Point> Series1 { get; set; } public List<Point> Series2 { get; set; } public List<Point> Series3 { get; set; } public SampleChartData() { Series1 = new List<Point>(); Series2 = new List<Point>(); Series3 = new List<Point>(); } }

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  • C# Get memberinfo for custom attribute's target

    - by Waldo Bronchart
    Given a custom attribute, I want to get the name of its target: public class Example { [Woop] ////// basically I want to get "Size" datamember name from the attribute public float Size; } public class Tester { public static void Main() { Type type = typeof(Example); object[] attributes = type.GetCustomAttributes(typeof(WoopAttribute), false); foreach (var attribute in attributes) { // I have the attribute, but what is the name of it's target? (Example.Size) attribute.GetTargetName(); //?? } } } Hope it's clear!

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  • get premitive , complex, ArrayEnumerable types

    - by john
    i have a separate class for each of my database entities and when i create an object of my class to reference the properties of a class it returns a circular reference which contains properties of other entities too that are related via FK ... to remove the circular reference i want to first make a copy of the object through "context proxy object" copy and then get the primitive, complex, arrayEnumerable types of that object and strip off these types from the object and then the object get returned by web service....

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  • Java: Using Dynamically loaded classes

    - by Snigger
    Hi I'm new to java. I'm trying to use some dynamically loaded classes in my application. The application doesn't know classes , Just it try to load a class by name that its name came from input. It doesn't know class (So I can't use casting) but just needs to call some methods of that class (every class should have that methods). I thought about interfaces but I don't know how. How can I call those methods? Thanks

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  • Is it possible to access the line of code where a method is called from within that method?

    - by Dan Tao
    Disclaimers: I am not interested in doing this in any real production code. I make no claim that there's a good reason why I'm interested in doing this. I realize that if this is in any way possible, it must involve doing some highly inadvisable things. That said... is this possible? I'm really just curious to know. In other words, if I have something like this: int i = GetSomeInteger(); Is there any way from within GetSomeInteger that the code could be "aware of" the fact that it's being called in an assignment to the variable i? Again: no interest in doing this in any sort of real scenario. Just curious!

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  • How do I instantiate Class Dynamically in Java?

    - by kunjaan
    I have the class name stored in a property file. I know that the classes store will implement IDynamicLoad. How do I instantiate the class dynamically? Right now I have Properties foo = new Properties(); foo.load(new FileInputStream(new File("ClassName.properties"))); String class_name = foo.getProperty("class","DefaultClass"); //IDynamicLoad newClass = Class.forName(class_name).newInstance(); Does the newInstance only load compiled .class files? How do I load a Java Class that is not compiled?

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