annotations

问题 I'm attempting to use Butter Knife to simplify creation of a custom BaseAdapter class. I'm following the example here: http://jakewharton.github.io/butterknife/ under the "Another use is simplifying the view holder pattern inside of a list adapter." section. Unfortunately, I am getting an "Unable to inject views" error each time the ViewHolder is created for each item in the list. Here is my code: public class ButterknifeCustomBaseAdapter extends BaseAdapter{ @Override public int getCount() {

问题 I m trying to get the annotation details from super type reference variable using reflection, to make the method accept all sub types. But isAnnotationPresent() returning false . Same with other annotation related methods. If used on the exact type, output is as expected. I know that annotation info will be available on the Object even I m referring through super type. @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.TYPE}) public @interface Table { String name(); } @Table(name =

问题 I am curious about Java-11 in general, but specifically JEP:323 which plans to add the var declaration to Lambda operation variables. The motivation behind this feature is discussed nicely here. Consider the following quote from the article: // #1 - Legal ITest divide = (@ATest var x, final var y) -> x / y; /* #2 Modifiers on Old-Style implicit paramaters => Illegal */ ITest divide = (@ATest x, final y) -> x / y; The usage of the final modifier is clear to me and is in line with immutability

问题 I'm trying to run Struts2 sample application.While starting the server I'm getting below error and code which using from here. I implemented same code same jars over here. struts2-convention-plugin-2.3.1.2.jar, asm.jar, antlr-2.7.6.jar, commons-fileupload-1.2.2.jar, commons-io-2.0.1.jar, commons-lang-2.5.jar, commons-logging-1.1.1.jar, commons-logging-api-1.1.jar, freemarker-2.3.18.jar javassist-3.11.0.GA.jar, ognl-3.0.4.jar, struts2-core-2.3.1.2.jar, xwork-core.2.3.1.2.jar Jun 29, 2013 6:58

问题 why the jpa annotations are applied on field or on getter methods. if i try to apply the annotations on setter method then compiler generate the error. because compiler ignore the annotation on setter method. what is the reason behind them? 回答1: This is is how it's specified. Per JPA Specification: When field-based access is used, the object/relational mapping annotations for the entity class annotate the instance variables, and the persistence provider runtime accesses instance variables

问题 I was trying to find simple example to understand the usage of apt command, but I couldn't find a helpful resource for this. I have referred this Getting Started with the Annotation Processing Tool but I do get a high level understanding. Moreover I want to write a code to test apt command. Can somebody post a simple example or better link to refer? 回答1: Here's an example of creating a Note annotation and associated processor: APT: Compile-Time Annotation Processing with Java Update. As of

问题 I want to write a java annotation which times the method call. something like this: @TimeIt public int someMethod() { ... } and when this method is invoked, it should output on console how long this method took I know how to do it in python, this is what I want it to do: from time import time, sleep def time_it(func): def wrapper(*args, **kwargs): start = time() func(*args, **kwargs) stop = time() print "The function", func.__name__, " took %.3f" % (stop - start) wrapper.__name__ = func._

问题 I am following a Spring 2.5 tutorial and trying, at the same time, updating the code/setup to Spring 3.0. In Spring 2.5 I had the HelloController (for reference): public class HelloController implements Controller { protected final Log logger = LogFactory.getLog(getClass()); public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { logger.info("Returning hello view"); return new ModelAndView("hello.jsp"); } } And a JUnit

问题 I'm writing a tool that uses the annotation processor to generate source code depending on the return type of methods of an annotated class. The return type is always some subtype (interface or class) of an interface A that defines a type variable T . interface A<T>{T m();}; I would like to find the type parameter for the method m() return value type variable T . The return type is represented by the annotation processor as a javax.lang.model.type.TypeMirror instance. The simplest case is to

问题 So I have an annotation on a function (DefDef). This annotation has parameters. However, I am confused on how to get the parameters from the constructor. Usage example: class TestMacro { @Foo(true) def foo(): String = "" foo } Here's the code for the annotation: class Foo(b: Boolean) extends StaticAnnotation { def macroTransform(annottees: Any*) = macro Foo.impl } object Foo { def impl(c: whitebox.Context)(annottees: c.Tree*): c.Expr[Any] = { import c.universe._ //how do I get value of `b`