从 bean 中找出全局 jndi 名称

Question

我在 JBoss 7.4 中部署了多个 JavaEE6 应用程序 (.war)。所有这些应用程序都包含一个提供 Singleton-Bean 实现的公共库。使用 JBoss 模块文件夹为每个应用程序配置不同的单例 bean，并且应该记录一些特定于应用程序的信息 - 这已经可以正常工作了。

但是我很难区分哪个日志行来自哪个应用程序。

当服务器为每个应用程序（my-app1、my-app2、...）启动时，我在日志中有以下输出：

INFO  10:45:54,998 (EjbJndiBindingsDeploymentUnitProcessor.java:setupJNDIBindings:183) -JNDI bindings for session bean named MyBean in deployment unit deployment "my-app1.war" are as follows:
java:global/my-app1/MyBean!my.package.MyBean
java:app/my-app1/MyBean!my.package.MyBean
java:module/MyBean!my.package.MyBean
java:global/my-app1/MyBean
java:app/my-app1/MyBean
java:module/MyBean

这个输出正是我所需要的，所以我想检索在我的代码中部署 MyBean 的全局 jndi 名称：

import javax.annotation.PostConstruct;
import javax.ejb.Singleton;
import javax.ejb.Startup;

import org.apache.log4j.Logger;

@Singleton
@Startup
public class MyBean {

    private static final Logger log = Logger.getLogger(MyBean.class);

    @PostConstruct
    private void postConstruct() {
        String appName = ""; // .getGlobalJndiNameOfThisInstance();
        log.info("MyBean available for application " + appName);
        // and log further application specific info
    }

}

在研究这个时，我只找到了大量关于如何通过 jndi 查找 bean 的信息，我不需要这些信息。我可以通过创建 new InitialContext() 以某种方式提取应用程序名称吗？

Answer 1

我找到了查找名称的方法。它可以通过名称 java:app/AppName 或 java:module/ModuleName.

下的 jndi-lookup 获得

我按如下方式扩展了我的 EJB：

import javax.annotation.PostConstruct;
import javax.ejb.Singleton;
import javax.ejb.Startup;

import org.apache.log4j.Logger;

@Singleton
@Startup
public class MyBean {

    @Resource(lookup = "java:app/AppName")
    String appName;

    private static final Logger log = Logger.getLogger(MyBean.class);

    @PostConstruct
    private void postConstruct() {
        log.info("MyBean available for application " + appName);
        // and log further application specific info
    }

}

Answer 2

import java.net.URL;
import java.util.*;
import javax.ejb.Stateless;
import javax.naming.*;
import net.sf.extcos.ComponentQuery;
import net.sf.extcos.ComponentScanner;

public class ServiceLocator {

public <T extends Object> T lookup(Class<T> interfaceLocal) {
    try {
        return (T) getInitialContext().lookup(buildJNDIWildfly(interfaceLocal));
    } catch (NamingException e) {
        throw new RuntimeException(e);
    }
}

public <T> String buildJNDIWildfly(final Class<T> interfaceLocal) {
    Class<? extends T> clazz = getImplementorOf(interfaceLocal, getPackagesToScan());
    if (clazz != null) {
        URL url = getUrlOfClass(clazz);
        String module = getModuleName(url);
        return "global/" + module + "/" + clazz.getSimpleName() + "!" + interfaceLocal.getName();
    }
    return null;
}

public String[] getPackagesToScan() {
    // important to reduce range of search
    return new String[] { "my.package.of.ejbs" };
}

public static URL getUrlOfClass(Class<?> clazz) {
    if (clazz == null) {
        throw new NullPointerException();
    }
    String resourceName = clazz.getName().replace('.', '/') + ".class";
    ClassLoader classLoader = clazz.getClassLoader();
    if (classLoader == null) {
        classLoader = ClassLoader.getSystemClassLoader();
    }
    return classLoader.getResource(resourceName);
}

public <T> Class<? extends T> getImplementorOf(final Class<T> interfaceLocal, final String... packagesToScan) {
    // https://sourceforge.net/projects/extcos
    final Set<Class<?>> classes = new HashSet<Class<?>>();
    ComponentScanner scanner = new ComponentScanner();
    scanner.getClasses(new ComponentQuery() {
        @Override
        protected void query() {
            select().from(packagesToScan).andStore(
                    thoseBeing(and(annotatedWith(Stateless.class), implementorOf(interfaceLocal))).into(classes))
                    .returning(none());
        }
    });
    if (classes.size() > 0) {
        return (Class<? extends T>) classes.iterator().next();
    } else {
        return null;
    }
}

private String getModuleName(URL urlOfClass) {
    if (urlOfClass != null) {
        // Ex:
        // vfs:/opt/jboss-eap-6.4/standalone/deployments/myEar.ear/my-module.jar/my/interface/local/MyInterface.class
        String filePath = urlOfClass.getFile();
        int earPosition = filePath.lastIndexOf(".ear");
        int jarPosition = filePath.lastIndexOf(".jar");
        String earName = null;
        String moduleName = null;
        if (earPosition >= 0) {
            earName = filePath.substring(filePath.lastIndexOf('/', earPosition) + 1, earPosition);
        }
        if (jarPosition >= 0) {
            moduleName = filePath.substring(filePath.lastIndexOf('/', jarPosition) + 1, jarPosition);
            if (earName != null) {
                moduleName = earName + "/" + moduleName;
            }
        }
        return moduleName;
    }

    return null;
}

private InitialContext getInitialContext() {
    try {

        Hashtable<String, String> props = new Hashtable<String, String>();
        props.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
        return new InitialContext(props);
    } catch (NamingException e) {
        throw new RuntimeException(e);
    }
}
}

从 bean 中找出全局 jndi 名称

Find out global jndi name from within bean

jndi

jboss7.x

jakarta-ee