java-ee

问题 Message-Driven Bean Class the requirements of a message-driven bean class: It must not define the finalize method. What is the reason for above requirement ? 回答1: If you look in the EJB spec, you will see that it is a requirement for all types of EJB. http://download.oracle.com/otndocs/jcp/ejb-3.1-pfd-oth-JSpec/ I can't find a definitive answer but looking on various Java forums over the last 13 years, you can see answers consistently saying that, because the container will decide the life

问题 I am migrating a Jsp-servlet based Java project that was hosted in websphere to tomcat. Following init-param is in web.xml inside a filter definition. I moved the properties file src folder which is classpath. How to change the following in the web.xml. Can I define properties file as init-param because most of the answers I saw has used context-param to define properties file. I dont think its an option to me as the existing application needs the properties file to be init-param. <init-param

问题 I have a <h:dataTable> that is populated from an Entity class and displays different products. I want to be able to click a <h:commandLink> and edit row that the link belongs to. I have structured it mostly the same way as this nice example and article at mkyong. The table (with some columns excluded): <h:form> <h:dataTable id="gnomeTable" value="#{gnome.productList}" var="item" styleClass="gnomeTable" headerClass="gnomeTableHeader" rowClasses="gnomeTableOddRow,gnomeTableEvenRow" bgcolor="

问题 I'm trying to create hyperlinks to open files from network drive G: (more details here). G: is mapped as network drive. When I deploy the WAR on Tomcat server integrated to Eclipse, it works . When I deploy it on the same but standalone Tomcat itself, it doesn't work I've tried: Run Tomcat as Domain Admin , which has an access to the location, but without success . Run it as Local user , but check the box Allow service to interact with desktop . Also without success . What's the difference in

问题 I have created an instatiator bean for Dozer (http://dozer.sourceforge.net/). But when I Inject this EJB it throws nullpointer exception. Here is my Singleton Startup Bean for intialising Dozer package com.unijunction.ordercloud.common.rest; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import javax.inject.Singleton; import javax.ejb.Startup; import org.dozer.DozerBeanMapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @Startup @Singleton public class

问题 I'm working on a service that runs in a java app server farm that needs to do some periodic jobs (say, once every 2 minutes). The service must interface to external entities, and it is necessary to synchronize the different instances so that only one of them works on the job at a given time. Since the service uses a DB during this job, I thought of implementing the synchronization based on a simple DB table: id, owner, stamp where id is the lock's id, owner is the current owner and stamp is

问题 I know that this issue was already raised here several time. However I couldn't find any solution which will help so I decided to post it again. I'm using Hibernate with Spring MVC framework and I'm trying to fetch my class wth sub class: public class Scene implements Serializable{ private Long id; private Author author; //omitting getters and setters } public class Author{ private Long id; Private String name; //omitting getters and setters } My Hibernate configuration is the following:

问题 after migrating to tomcat 7.0.22 and installing t7mp ( tomcat 7 plugin from google code ) i am running on maven 2 btw when trying to run mvn t7:run , i got the following exception: WARNING: Unable to load class [com.sun.jmx.mbeanserver.MBeanInstantiatorImpl] to check against the @HandlesTypes annotation of one or more ServletContentInitializers. java.lang.IncompatibleClassChangeError: Implementing class at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader

问题 I am new to jax-rs and i am stuck with subresources. Take a look. this is not working @Path(..) public class Test { @Path(...) public SubResource getSub(){ return new SubResource(); } } public class SubResource { @Inject private MyBean myBean; @GET public String getStr(){ return myBean.getStr(); // myBean is null, injection didnt work properly } this works, but why???? @Path(..) public class Test { @Context private ResourceContext context; @Path(...) public SubResource getSub(){ return

问题 I have some JPA entity classes residing in a Wildfly module. Although there are entity classes in this module, there's no JPA deployment descriptor (persistence.xml file) in the module. Here's the complete path of the module: {Wildfly_installation}/modules/system/layers/base/br/edu/ufca/main/ufca.jar The module descriptor (located in the same folder): <?xml version="1.0" encoding="UTF-8"?> <module xmlns="urn:jboss:module:1.3" name="br.edu.ufca"> <resources> <resource-root path="ufca.jar"/> <