classloader

问题 I am developing a personal medicine time reminder application.It is working almost properly except the fact that it is stopping after notifying the medicine time a few times. While monitoring the log cat of the application i found that it is stopping the alarm receiver after getting the following Warning. W/System: ClassLoader referenced unknown path: /data/app/com.example.sakkar.medicineschedular-2/lib/arm Can anyone help me to solve this problem? 回答1: It's been few weeks now and not sure if

问题 As part of an HTTP WebServer project for academic purposes, I'm trying write my own custom class loader for web application classes, but can't seem to get it right. Generally speaking, web applications are located in their own folders, the ".class" file of the web application is the same as it's direct parent folder name. (e.g. Web1/Web1.class). The below code works fine until I reach the defineClass() method, and then it throws me out with the following exception: java.io

问题 I have an object A1 of type A. I dynamically find that out , that object A1 is of type A. I now have a property say "Name" which I want to access from A1 , how do I do it ? Now the biggest problem is that the object A1 can even be of type B. If it is of type B then I will have to obtain the value "Address". Now How I resolve this ? Below code does the type check , public static void testing(Object A1, String s) s - Classtype { try{ Class c = Class.forName(s); if( c.isInstance(A1)) // { //Now

问题 I want to develop a DB-Agnostic application in java. I have chosen hibernate as ORM. The problem with jdbc is that , it is just an interface and we need the driver class of the db in the class path. Since the database should be configurable i have to go for loading the driver class of DB dynamically. (User should keep the driver class in a folder and it should be loaded dynamically ) Below is my code. File driverJar = new File("E:\\Jomon\\backup_2017_05_25\\2.2\\WS\\2.2_1\\lib\\Drivers\

问题 I have read somewhere that if class A is loaded by ClassLoaderA then all the classes A depends on will be loaded by ClassLoaderA . Is it true? If it is true, then why we need to set the context class loader? like this one: http://blog.markturansky.com/archives/21, thanks in advance. 回答1: The Javadocs say the following about the class loaders: The ClassLoader class uses a delegation model to search for classes and resources. Each instance of ClassLoader has an associated parent class loader.

问题 This question already has answers here : Why am I getting a NoClassDefFoundError in Java? (23 answers) Closed 3 years ago . I am currently facing with a problem where I am running a Jasper report application. After invoking a report generation request I am facing java.lang.NoClassDefFoundError for an application class e.g. com.abcd.framework.web.servicelocator.ServiceLocator I verified that the class is present at the appropriate path under the tomcat/WEB-INF/classes folder. I also enabled

问题 The code is as follows what it does is it loads all the classes inside a jar file which I placed inside my home directory . import java.io.File; import java.util.jar.JarFile; import java.util.jar.JarEntry; import java.net.URLClassLoader; import java.net.URL; import java.util.Enumeration; import java.lang.ClassLoader; public class Plugin extends ClassLoader { public static void main(String[] args) throws Exception { File file = new File(System.getProperty("user.home") + "/HelloWorld.jar");

问题 In the code below I generate a class dynamically using sun.tools.javac.Main . I will create a new instance of this class using Reflection. The problem is, I want to avoid using Reflection to invoke the method I defined for this class, so I created a ProxyInvoker that references an interface I defined in my project. In order for the classloader to see this, I add the classpath to the Executable interface to my classloader. I still get an error during the 'compilation' step that says that my

问题 I'm trying to make VertX Mertrics work when running via the exec:java Maven plugin. All works as expected when I package the application into a fatjar and run it with java -jar fat.jar -conf config.json -Dvertx.metrics.options.enabled=true When I run it with mvn clean package exec:java -DskipTests I see: 2016-03-22 18:39:58.833 WARN i.v.c.i.VertxImpl:348 - Metrics has been set to enabled but no VertxMetricsFactory found on classpath I tried several approaches: adding io.vertx:vertx-dropwizard

问题 I have an extremely puzzling situation and looking for any ideas. I'm running a small Spring MVC app, where I make use of the RequestMapping annotation on my controller " AnsController ". When RequestDispatcher is scanning my beans for the RequestMapping annotation, at some point it comes down to this line: clazz.getAnnotation(RequestMapping.class) (clazz = AnsController.class) The line above does not find the annotation, even though it is there. I started investigating this in Eclipse