classloader

Beanshell will not allow me to add jars to the “default” JRE classloader?

由 前提是你 提交于 2019-12-10 19:43:11
问题 I have a question about Beanshell that I can't find an answer to anywhere. I am only able to run Beanshell scripts in 1 of 2 ways: Where Classpath is defined before invoking Beanshell and Beanshell uses the JRE default classloader. Where no classpath is defined at all before starting Beanshell and then I use addClassPath() and importCommands() to dynamically build the classpath within Beanshell's classloader. This method does not seem to inherit a jars that were part of the default JRE

when is a class is unloaded [duplicate]

由 ￣綄美尐妖づ 提交于 2019-12-10 17:12:15
问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Unloading classes in java? public class MyClassLoader extends ClassLoader { private static final int BUFFER_SIZE = 8192; } As per my knowledge a class is loaded by classLoader in JVM when it requires that particlar class . But you please tell me when a class is exactly unloaded ?? 回答1: Classes are eligible to be unloaded if the class loader is GC'ed. So in your example, there are no more references to

Loading partial entities with Linq to Entities

由 心已入冬 提交于 2019-12-10 14:31:34
问题 I am trying to load a partial entity with Linq to Entities: Dim contacts = From c In My.Context.Contacts _ Select New Contact With { _ .ContactId = c.ContactId, _ .Name = c.Name } I tried it and I get the following NotSupportedException: " The entity or complex type 'CompleteKitchenModel.Contact' cannot be constructed in a LINQ to Entities query. " Thanks 回答1: You'll have to use anonymous type: Dim contacts = From c In My.Context.Contacts _ Select New With { _ .ContactId = c.ContactId, _

java.lang.LinkageError: loader constraint violation

由 空扰寡人 提交于 2019-12-10 14:08:46
问题 Good day everyone, i have faced with such an issue as linkage error like this: java.lang.LinkageError: loader constraint violation: when resolving method "javax.xml.transform.Transformer.transform(Ljavax/xml/transform/Source;Ljavax/xml/transform/Result;)V" the class loader (instance of org/jboss/mx/loading/UnifiedClassLoader3) of the current class, org/richfaces/renderkit/TemplateEncoderRendererBase, and the class loader (instance of <bootloader>) for resolved class, javax/xml/transform

Do security providers cause ClassLoader leaks in Java?

由 岁酱吖の 提交于 2019-12-10 10:56:12
问题 In my Java EE (Glassfish 3.1.1) application I register a security provider: public static final class XoauthProvider extends Provider { public XoauthProvider() { super("Google Xoauth Provider", 1.0, "Provides the Xoauth experimental SASL Mechanism"); put("SaslClientFactory.XOAUTH", "blah.server.utils.XoauthSaslClientFactory"); } } ... XoauthProvider xoauthProvider = new XoauthProvider(); Security.addProvider(xoauthProvider); I have been receiving following exceptions after redeploys: java

How to load a velocity template into an EJB to be used as a mail template

由 自作多情 提交于 2019-12-10 10:27:43
问题 I have a Java EE 6 application in which I'd like to use velocity to generate mails from a template. I have a @Named bean which is responsible for loading and filling a particular template. The project is a web application, so I placed my templates into WEB-INF/classes (which btw seems to be rather ugly, but I didn't find a more elegant solution by now) and used the ClasspathResourceLoader to access the files. The configuration is as follows: Properties props = new Properties(); props

classloader总结

由 霸气de小男生 提交于 2019-12-10 08:09:57
classloader是什么 我的理解classloader就是加载我们的类到内存的类，他主要就是寻找资源，即找到在他能搜索到的路径中，有没有我们的类。有的话就加载到内存。 系统的classloader 系统的classloader有三种 Bootstrap ClassLoader 负责加载java基础类，主要是 %JRE_HOME/lib/ 目录下的rt.jar、resources.jar、charsets.jar和class等 Extension ClassLoader 负责加载java扩展类，主要是 %JRE_HOME/lib/ext 目录下的jar和class App ClassLoader 负责加载当前java应用的classpath中的所有类。 双亲委托机制 系统的classloader实行的是双亲委托机制，双亲委托机制就是在加载类的时候先去父类（此处的父类不是继承里面的父类，双亲委托机制是组合）里查找，如果父类加载到了就算子类的可以在自己的路径下找到，也不能加载。只会从父类中取到加到后的class。这样的好处就是不会重复加载类。 此处只是说系统的classloader，因为你自己写的classloader不一定要遵循这个机制，而且有些情况必须不能遵循，例如tomcat等服务器，加载的时候不会遵循双亲委托（他的classloder是自己实现的），他是优先自己加载

ClassLoader在jvm和tomcat中的区别

由 ≯℡__Kan透↙ 提交于 2019-12-10 08:09:40
发现问题： 前段时间使用ClassLoader类的方法来加载classPath路径下的配置文件，其中用到 getSystemResource (String name) 、 getSystemResourceAsStream (String name) 、 getSystemResources (String name) 这几个方法的时候出现问题。 问题出现在，程序用main方法的方式运行的时候能够正常运行，但是使用tomcat运行的时候就会报空指针异常。 原因： 两种方式运行的ClassLoader加载机制不同，导致了不同的结果。 main方法运行是启动的本地的jdk来加载类，加载机制是： Java默认提供的三个ClassLoader BootStrap ClassLoader ：称为启动类加载器，是Java类加载层次中最顶层的类加载器， 负责加载JDK中的核心类库，如：rt.jar、resources.jar、charsets.jar等 ，这个是通过native方法调用C语言实现的。 Extension ClassLoader ：称为扩展类加载器，负责加载Java的扩展类库，默认加载JAVA_HOME/jre/lib/ext/目下的所有jar。 App ClassLoader ：称为系统类加载器，负责加载应用程序classpath目录下的所有jar和class文件。

Tomcat 6 vs 7 - lib vs shared/lib - jars only?

由 假如想象 提交于 2019-12-10 04:30:24
问题 When upgrading from Tomcat 6 to Tomcat 7 - we kept a number of files we wanted on the classpath in the $CATALINA_HOME/lib directory on 6 - and it made sense to move these two $CATALINA_HOME/shared/lib on Tomcat 7. What we've found is that the jar files went across ok - but anything that wasn't a jar file - eg an xml file etc was not picked up by the class loaded in the shared/lib directory. When we moved the non-jar files back to the $CATALINA_HOME/lib directory - they loaded into the

Why ContextClassLoader returns path with exclamation character?

由 半腔热情 提交于 2019-12-10 04:20:46
问题 I try to open file in jar in WEB-INF/lib with Thread.currentThread().getContextClassLoader(); URL url=classLoader.getResource(myconfig); In debugger I can see: jar:file:/C:/apache-tomcat/webapps/mywebapp/WEB-INF/lib/myjarresource.jar! /conf/configuration.xml Why in file path is "!" ? I think for this reason application cannot open this file. How to receive correct path? Thanks. 回答1: It means whatever comes after the ! is inside the JAR file. In case of myjarresource.jar!/conf/configuration
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