小编Dag*_*Dag的帖子

如何在注释中设置值？

我定义了以下注释:

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface JsonElement {
    int type();
}

以下是在POJO类中使用它的方法

@JsonElement(type=GETTER_METHOD)
public String getUsername{
........................
}

而util类使用反射来检查此方法是否存在JSonElement注释,并检查类型值是什么.

Method methods[] = classObject.getClass().getDeclaredMethods();

        JSONObject jsonObject = new JSONObject();
        try {
            for (int i = 0; i < methods.length; i++) {
                String key = methods[i].getName();
                System.out.println(key);
                if (methods[i].isAnnotationPresent(JsonElement.class) && key.startsWith(GET_CHAR_SEQUENCE)) {
                    methods[i].getDeclaredAnnotations();
                    key = key.replaceFirst(GET_CHAR_SEQUENCE, "");
                    jsonObject.put(key, methods[i].invoke(classObject));
                }

            }
            return jsonObject;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }

我如何找出type()价值是多少？我可以找到是否存在注释,但我找不到一个方法来找出设置的值 - 如果有的话type().

我发现了 gzipped tarbar（.tgz或.tar.gz）的几种定义，哪一个是正确的，有吗？

• application/x-gtar（维基百科，一些 bugtracker）
• application/x-tar-gz（论坛，Python）

在官方列表中未找到匹配项。

我在我的应用程序（这是一个Dropwizard应用程序）中将Slf4j 1.7.x与Logback结合使用。现在，我们有了使用log4j2（而不是log4j）的库，日志记录转到/dev/null。我无法在任何现有的Maven应用程序中找到logj2-over-slf4j或log4j2-to-slf4j库，诀窍是什么？

我想更改嵌入式HornetQ中的默认端口.这在hornetq-configuration.xml文件中完成时有效:

<acceptors>
  <acceptor name="netty-acceptor">
    <factory-class>org.hornetq.integration.transports.netty.NettyAcceptorFactory</factory-class>
    <param key="port" value="6446"/>
  </acceptor>
</acceptors>

但是以编程方式改变不会.我从文件加载配置,并尝试覆盖,但没有成功 - 这是我尝试:

// Load configuration
FileConfiguration configuration = new FileConfiguration();
configuration.setConfigurationUrl("hornetq-configuration.xml");

// Prepare configuration objects
String netty = NettyAcceptorFactory.class.getName();
Map<String, Object> transportParams = new HashMap<String, Object>();
transportParams.put(TransportConstants.HOST_PROP_NAME, "localhost");
transportParams.put(TransportConstants.PORT_PROP_NAME, 6446);
TransportConfiguration transpConf = new TransportConfiguration(netty, transportParams);

// add configuration (clearing before didn't helped either))
configuration.getAcceptorConfigurations().add(transpConf);
configuration.start(); // moving this right after the setting the file didn't helped

// start server
HornetQServer server = HornetQServers.newHornetQServer(configuration);
JMSServerManager jmsServerManager = new JMSServerManagerImpl(server, …

我希望从我的应用程序中嵌入的HornetQ的所有日志记录委托给slf4j.不幸的是,任何尝 我已经尝试过了

• 添加了jul-to-slf4j
• 安装了这座桥 SLF4JBridgeHandler.install();
• 试过Log4jLogDelegateFactory("hornetq-configuration.xml"经过<log-delegate-factory-class-name>org.hornetq.integration.logging.Log4jLogDelegateFactory</log-delegate-factory-class-name>)
• 写我自己LogDelegate和LogDelegateFactory

但无论我做什么,下面的线路都没有抓住:

13.07.2011 17:42:11 org.hornetq.core.logging.impl.JULLogDelegate warn
WARNUNG: AIO wasn't located on this platform, it will fall back to using pure Java NIO. If your platform is Linux, install LibAIO to enable the AIO journal
13.07.2011 17:42:11 org.hornetq.core.logging.impl.JULLogDelegate info
INFO: Using NIO Journal
13.07.2011 17:42:11 org.hornetq.core.logging.impl.JULLogDelegate info
INFO: Started Netty Acceptor version 3.1.5.GA-r1772

我错过了什么？

我正在使用一个新的ActiveMQ 5.8.0安装,我在队列中有一条名为'testing'的消息.我还替换了ACTIVEMQ_SUNJMX线bin/activemq以启用JMX:

ACTIVEMQ_SUNJMX_START="-Dcom.sun.management.jmxremote.port=1099 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false"

然后我通过以下代码查询JMX:

    try {
        JMXConnector connector = JMXConnectorFactory.connect(new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi"));
        connector.connect();
        MBeanServerConnection connection = connector.getMBeanServerConnection();

        ObjectName mbeanName = new ObjectName("org.apache.activemq:BrokerName=localhost,Type=Broker");
        BrokerViewMBean mbean = MBeanServerInvocationHandler.newProxyInstance(connection, mbeanName, BrokerViewMBean.class, true);

        System.out.println("Id:" + mbean.getBrokerId()); // here the exception will be thrown
    }
    catch (Exception x) {
        x.printStackTrace();
    }

访问mbean时抛出异常.

java.lang.reflect.UndeclaredThrowableException
    at $Proxy0.getBrokerId(Unknown Source)
    at testing.TestJmx.main(TestJmx.java:25)
Caused by: javax.management.InstanceNotFoundException: org.apache.activemq:BrokerName=localhost,Type=Broker
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1095)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:643)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:668)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1424)
    at javax.management.remote.rmi.RMIConnectionImpl.access$200(RMIConnectionImpl.java:89)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1292)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1380)
    at javax.management.remote.rmi.RMIConnectionImpl.getAttribute(RMIConnectionImpl.java:621)
    at sun.reflect.GeneratedMethodAccessor30.invoke(Unknown Source)
    at …