Is there a preference or behavior difference between using:
if(obj.getClass().isArray()) {}
and
if(obj instanceof Object[]) {}
?
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Hey anyone,
I got a question about Java Reflections: I have to checkout, if a certain field of a class is an array.
But my problem is: If i run isArray() on the ... |
I need to invoke a method without knowing a priori what will the amount of arguments be.
I've tried using the member Method.invoke(Object, Object...) passing as second parameter an array of objects ... |
I don't understand the nature of Java Beans that well. Well, at least how I see them used in some code-bases that pass through our shop.
I found this question:
http://stackoverflow.com/questions/315142/java-beans-what-am-i-missing
The accepted ... |
Hi I have the following requirement.
I want to create variable number of String arrays in a method, based on the number of levels present.
For e.g
I have the variable numOfLevels (int) received ... |
I have a Class variable that holds a certain type and I need to get a variable that holds the corresponding Array type. The best I could come up with is ... |
How do I find the length of a multi-dimensional array with reflection on java?
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I am trying to fill a RealVector (from Apache Commons Math) with values. I tried using the class's append method, but that didn't actually add anything. So now I'm ... |
Is it possible to use getConstructor to obtain the constructor of the class X below?
public class A {
}
public class Y {
}
public class X extends Y {
public X(A ...
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I am doing some reflection work and go to a little problem.
I am trying to print objects to some GUI tree and have problem detecting arrays in a generic way.
I suggested ... |
I'm writing a routine to invoke methods, found by a name and an array of parameter Class values
Matching the Method by getName works, but when trying to match the given Class[] ... |
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, ... |
I have
Class<? extends Object> class1 = obj.getClass();
Field[] fields = class1.getDeclaredFields();
for (Field aField : fields) {
aField.setAccessible(true);
...
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I wrote a simple library in which the user extends one of my abstract classes and then passes that class to one of my functions.
//user class
class My_robot extends Robot{
}
//My library function
function ...
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Given a Class<?> that describes class A, is it somehow possible to get the Class<?> that matches the class A[]?
Class<?> clazz = A.class;
Class<?> arrayclazz = clazz.toArray(); // ??
assert arrayclazz.equals(A[].class);
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I am writing a program that displays the methods inside a Class along with it's access modifier, return type and parameters.
Here's my code
import java.lang.reflect.*;
class RefTest1{
public static void ...
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running the folowing code:
public class Test {
public Test(Object[] test){
}
public static void main(String[] args) throws Exception{
...
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I'm in the middle of a contender for the greatest kludge of all time. I need to use Spring JDBC without ever making reference to it. A custom classloader is providing ... |
I'm doing some code generation using reflection and need to get the string describing certain array types in code. The default API doesn't really make this easy.
(new int[12]).getClass().getName() returns [I(new Date[2][]).getClass().getName() ... |
I am trying to invoke the API with the given input parameters. Input params are coming as a List. Now my job is get the API's parameter types one by one ... |
According to the doc and to this answer I shuold be having "Override" ( or something similar ) in the following code:
import java.lang.reflect.*;
import java.util.*;
import static java.lang.System.out;
class Test { ...
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My class A has
AClaz[] rofl;
The documentation for getDeclaredFields says "This method returns an array of length 0 if the class or interface declares no fields, or if this ... |
I've got to maintain some code written by someone else who is no longer with the company. I'm seeing several references to java.lang.reflect.Array.getLength(anArray). Its working, but I've never seen ... |
I am trying to unpack an array I obtain from reflecting an objects fields.
I set the value of the general field to an Object. If it is an Array I then ... |
I am new in Java and have a task to write some application. Faced one problem which can not pass :(
The issue is to update an array element through reflection (app ... |
I don't believe it's the call to getDeclaredMethod() that's the problem -- I believe it's the call to invoke(), where the underlying method wants an Object[] (an array of arguments) and you're passing a String[], which is itself an Object[], and it is being misinterpreted as the list of arguments itself, rather than as a single element of that list. You'd ... |
Im not quite sure I follow what you've said. Should I make an object out of the method I want to call like this (example)? Class c = classLoader.loadClass("testClass"); Method[] cMethods = c.getMethods(); Object methodObj = cMethods[1]; invoke(methodObj, null); this gives me the compiler error: fileloader2.java [20:1] cannot resolve symbol symbol : method invoke (java.lang.Object, location: class fileloader2 invoke(methodObj, null); ^ ... |
Hi All, I am using Reflection (java 1.4.2) to read an object and display its instance variables and the values they hold. I am facing a problem with reading instance variables of type array. The difficulty is explained below: if( field.getType().isArray() ) { Objecy obj = field.getObj(); //The obj can be an array of a primitive or any //reference type. Now, ... |
Hey, using reflections is considered a hint for a bad architecture of your program, so unless there is good reason and you really know what you're doing, don't use it. If you can't help it and still have to use reflections: The getClass() method of Object provide useful method you might want to check into. |
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I may not have made myself clear (then again, I may have). I would like to determine the array size from a Class or Field object, not from an array object. That is: class Able { class NotAble { int ary = new int[20]; } public void method() { Class c = NotAble.class; Field[] f = c.getDeclaredFields(); // Now, how do ... |