package com.carmelouria.logging.test;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
/**
 * @author Carmelo Uria
 *
*/
public class LoggingSample
{
    private static Logger logger = Logger.getLogger(LoggingSample.class.getName());
    /**
     * 
     */
    public LoggingSample()
    {
        super();
        PropertyConfigurator.configure("c:/temp/log4j.properties");
        logger.log(Level.INFO, "LoggingSample instantiation...");
        System.out.println("finished...");
    }
    public static void main(String[] args)
    {
        LoggingSample sample = new LoggingSample();
    }
}

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WebServiceAppender

WebServiceAppender 是必需的，它可以将消息发送到指定çš?Web 服务ã€?code>WebServiceAppender ¾l§æ‰¿äº?org.log4j.AppenderåQŒå®ƒå…è®¸ä½¿ç”¨ log4.propertiesåQŒåƈ成äؓ有效çš?Log4j Appenderã€?/p>

WebServiceAppender 使用åŸÞZºŽ XML çš„è¿œ½E‹è¿‡½E‹è°ƒç”?(JAX-RPC) çš?Java APIåQŒæ¥ž®†æ¶ˆæ¯å‘送到服务器。JAX-RPC 是一¿Uè§„范，它描˜qîC‹Éç”? RPC å’?XML 构徏 Web 服务å’?Web 服务客户端的应用¾~–程接口 (API) 和约定。JAX-RPC 又被¿UîCØ“ JSR 101ã€?/p>

LoggingEvent 通过 SOAPElement 被分割åƈ表示ä¸?XML。javax.xml.soap.SOAPElement 接口意味着服务端点接口ž®†åŒ…含一个参敎ͼŒæˆ–è¿”å›?javax.xml.soap.SOAPElement ¾cÕdž‹çš„å€û|¼Œä»¥å¯¹åº”于 schema 中每个ä‹Éç”?code><xsd:any/>的地斏V€‚从本质上看åQŒå®ƒæ˜?XML 参数的封装，且没有相应的序列åŒ?反序列化 JAVA ¾c…R€‚例如，一旦客戯‚¯·æ±‚记录一个消息，ž®×ƒ¼šåˆ›å¾ä¸€ä¸?LoggEvent 对象åQŒç„¶åŽä¼ é€ç»™ Appender。在˜q™ç§æƒ…况下，Appender ž®±æ˜¯ WebServiceAppender。Appender ‹‚€ç´¢äº‹ä»Óž¼Œòq¶åœ¨è§£æžäº‹äšg中的信息。一些额外的信息会被加入åQŒå¦‚ä¸ÀLœºåç§°åQŒè¿™æ äh‚¨ž®ÞqŸ¥é“这些消息来自哪个系¾lŸã€‚同æ—Óž¼Œappend æ–ÒŽ³•ä¹Ÿå°†æ¶ˆæ¯è½¬æ¢ä¸?SOAPElementåQŒè¿™æ ·å°±å¯ä»¥é€šè¿‡ executeWebService æ–ÒŽ³•ž®†æ¶ˆæ¯ä¼ é€’ç»™ Web 服务。ä‹Éç”?SOAPElement 充分考虑äº?WebServiceAppender 未来版本的可扩展性问题ã€?/p>
清单4åQšæ‰§è¡?WebServiceAppender 服务çš?Append æ–ÒŽ³•

protected void append(LoggingEvent event) { // create Web Service client using endpoint if (endpoint == null) { System.out.println("no endpoint set. Check configuration file"); System.out.println("[" + hostname + "] " + this.layout.format(event)); return; } executeWebService(event); } private void executeWebService(LoggingEvent event) { SoapClient client = new SoapClient(); URL endPoint = null; try { endPoint = new URL(getendpoint()); } catch (MalformedURLException e1) { e1.printStackTrace(); } String nameSpace = "http://ejb.logging.carmelouria.com"; QName serviceName = new QName(nameSpace, "LogAppenderServiceService"); QName operation = new QName(nameSpace, "log"); QName port = new QName(nameSpace, "LogAppenderService"); Parameter message = new Parameter("log", Constants.XSD_ANY, SOAPElement.class, ParameterMode.IN); try { /** *create SOAPElement from LoggingEvent need hostname */ Level level = event.getLevel(); String sysLog = "<syslog>" + new Integer(level.getSyslogEquivalent()).toString() + "</syslog>"; String startTime = new Long(LoggingEvent.getStartTime()).toString(); String timeTag = "<start_time>" + startTime + "</start_time>"; String hostName = "<hostname>" + InetAddress.getLocalHost() + "</hostname>"; String threadName = "<thread_name>" + event.getThreadName() +"</thread_name>"; String logger = "<logger>" + event.getLoggerName() + "</logger>"; String eventMessage = "<message>" + event.getRenderedMessage() + "</message>"; String log = hostName + threadName + logger + timeTag + sysLog + eventMessage; String throwableInformation[] = event.getThrowableStrRep(); if (throwableInformation != null) { for (int i = 0; i < throwableInformation.length; i++) { String throwable = "<throwable_information>" + throwableInformation[i] + "</throwable_information>"; log += throwable; } } String ndcString = event.getNDC(); if (throwableInformation != null) { String throwable = <ndc>" + ndcString + </ndc>"; log += throwable; } message.setValue(SOAPElementFactory.create(<log>" + log + </log>")); } catch (UnknownHostException unknownHostException) { unknownHostException.printStackTrace(); } catch (SOAPException e2) { e2.printStackTrace(); } Parameter resultType = newParameter("logResponse", Constants.WEBSERVICES_VOID, Object.class, ParameterMode.OUT); Parameter[] parameters = { message }; try { // execute client Object result = client.execute(endPoint, serviceName, operation, "wrapped", null, port, resultType, parameters); if ((result != null) && (result instanceof String)) System.out.println((String) result); } catch (ClientException e) { e.printStackTrace(); } }

Hostname

不幸的是åQŒLog4j çš?LoggingEvent 没有包含 HostnameåQŒè€?Hostname æ˜?Web Service Appender 众多需求之一。在创徏 SOAPElement 以前åQŒæ‚¨å¯ä»¥ç”¨ä¸‹é¢çš„语句ž®?Hostname æ·ÕdŠ åˆ?XML æ–‡äšg里：

String hostName = "<hostname>" + InetAddress.getLocalHost() + "</hostname>";

SoapElementFactory

SoapElementFactory 是主要用于创å»?SOAPElement 的类。它同时支持创徏 IBM å’?Java çš?SOAPElement 实现åQŒå¦‚清单 5 所½Cºï¼š

    public static javax.xml.soap.SOAPElement create(String xml) throws SOAPException
    {
        com.ibm.ws.webservices.engine.xmlsoap.SOAPFactory factory =
        (com.ibm.ws.webservices.engine.xmlsoap.SOAPFactory) 
        com.ibm.ws.webservices.engine.xmlsoap.SOAPFactory
                .newInstance();
        SOAPElement element =
                  (javax.xml.soap.SOAPElement)factory.createElementFromXMLString(xml);
        return(element);
    }
    public static SOAPElement create(String arg0, String arg1, String arg2, 
                                                            boolean ibmSoapElement) throws 
                                                            SOAPException
    {
        if (ibmSoapElement)
        {
            SOAPFactory soapFactory =
              (com.ibm.ws.webservices.engine.xmlsoap.SOAPFactory)
              com.ibm.ws.webservices.engine.xmlsoap.SOAPFactory.newInstance();
            return (soapFactory.createSOAPElement(arg0, arg1));
        }
        javax.xml.soap.SOAPFactory soapFactory =
                        javax.xml.soap.SOAPFactory.newInstance();
        return (soapFactory.createElement(arg0, arg1, arg2));
    }

SoapClient

SoapClient ¾cÕd°è£…了 Call 接口çš?JAX-RPC 实现åQŒjavax.xml.rpc.Call 接口提供了对服务端点动态调用的支持。javax.xml.rpc.Service 接口ž®±å¥½è±¡æ˜¯åˆ›å¾ Call 实例的工厂ã€?/p>

清单 6 说明了客æˆïL«¯å¦‚何动态调用服务。这允许å¯ÒŽœåŠ¡è¿›è¡Œå˜æ›ß_¼Œè€Œæ— éœ€ç”Ÿæˆå®¢æˆ·ç«¯ä»£ç†æ¥è®‰K—®˜qœç¨‹æœåŠ¡ã€?/p>
清单 6åQšä‹Éç”?SoapClient ¾cȝš„调用æ–ÒŽ³•

private Object call(SoapService service, QName operation, QName portType, String operationStyleProperty, String encodingURIProperty, Parameter returnType, Parameter[] parameters) throws ClientException { QName portName; String response = null; Object results = null; Call call = null; try { // check to see if Service object exists if (service == null) throw new ClientException("Invalid Service object. It maybe null."); // retrieve call from Service object call = service.createCall(); call.setOperationName(operation); call.setPortTypeName(portType); // check call object if (call == null) throw new ClientException("invalid operation. Call object is null."); // set default values if (operationStyleProperty == null) call.setProperty(Call.OPERATION_STYLE_PROPERTY, OPERATION_STYLE_DOCUMENT_TYPE); else call.setProperty(Call.OPERATION_STYLE_PROPERTY, operationStyleProperty); if (encodingURIProperty == null) call.setProperty(Call.ENCODINGSTYLE_URI_PROPERTY, ENCODING_LITERAL); else call.setProperty(Call.ENCODINGSTYLE_URI_PROPERTY, encodingURIProperty); call.setTargetEndpointAddress(service.getServiceEndPoint()); //create Parameter class for SoapClient for (int i = 0; i < parameters.length; i++) { Class classObject = parameters[i].getClassObject(); if (classObject != null) call.addParameter(parameters[i].getName(), parameters[i].getXmlType(), parameters[i].getClassObject(), parameters[i].getMode()); else call.addParameter(parameters[i].getName(), parameters[i].getXmlType(), parameters[i].getMode()); } // pass parameter as ReturnType if (returnType != null) { if (returnType.getClassObject() != null) call.setReturnType(returnType.getXmlType(), returnType.getClassObject()); else call.setReturnType(returnType.getXmlType()); } Object[] request = new Object[parameters.length]; // add parameter values for (int i = 0; i < request.length; i++) { request[i] = parameters[i].getValue(); } results = call.invoke(request); } catch (SOAPFaultException e) { System.out.println(e.getFaultString()); e.getStackTrace(); throw new ClientException(e.getLocalizedMessage(), e); } catch (ServiceException serviceException) { serviceException.getStackTrace(); throw new ClientException(serviceException.getLocalizedMessage(), serviceException); } catch (RemoteException exception) { exception.printStackTrace(); throw new ClientException(exception.getLocalizedMessage(), exception); } return (results); }

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服务¾l„äšg

Log4j.server.properties

Log4j.server.properties æ–‡äšg包含了一个基本的 Log4j 配置文äšgåQŒè¯¥æ–‡äšg可以让您指定把哪些日志发送给 Web 服务¾pȝ»Ÿã€?/p>
清单 7åQšLog4j.server.properties æ–‡äšg

#set the level of the root logger log4j.rootLogger = INFO, FILE #set own logger log4j.appender.FILE=org.apache.log4j.RollingFileAppender log4j.appender.FILE.file=c:/temp/log4j/server/server.log log4j.appender.FILE.layout=org.apache.log4j.PatternLayout log4j.appender.FILE.layout.ConversionPattern=%p [%t] %c{2} (%M:%L) :: %m%n

LogAppenderBean.java

LogAppenderBean.java æ˜?Web Service Appender 服务所要ä‹É用的 EJB。该服务启动 LogAppenderBean 以处理来自每ä¸?Web Service Appender 客户端的每一个请求ã€?/p>

清单 8 昄¡¤ºäº†æ¥è‡?WebServiceAppender EJB çš?log æ–ÒŽ³•åQŒè¯¥æ–ÒŽ³•è§£æžæ¥è‡ªå®¢æˆ·ç«¯çš„消息åQŒåƈž®†å®¢æˆïL«¯ä¿¡æ¯¾Uªå½•åˆ°æœåŠ¡çš„服务器端ã€?/p>
清单 8åQšLogAppenderBean çš?log æ–ÒŽ³•

public void log(SOAPElement message) { try { InputSource source = ((IBMSOAPElement) message).toInputSource(false); Document document = Parser.parse(source); String log = null; String hostname = document.selectSingleNode("http://hostname").getText(); String threadName = document.selectSingleNode("http://thread_name").getText(); String syslog = document.selectSingleNode("http://syslog").getText(); String startTime = new Long( document.selectSingleNode("http://start_time"). getText()).toString(); log = '[' + startTime + ':' + hostname + ':' + threadName + "] " + document.selectSingleNode( "http://message").getText(); // retrieve any throwable messages List throwableList = document.selectNodes( "http://throwable_information"); if(throwableList != null) { Iterator throwables = throwableList.iterator(); while(throwables.hasNext()) { log += '\n' + ((Node)throwables.next()).getText(); } log += '\n'; } logger.log(Level.toLevel(new Integer(syslog).intValue()), log); logger.log(Level.INFO,log); } catch(ParserException parseException) { parseException.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } }

通过 IBM SOAPElement çš?InputSourceåQŒæ¯ä¸€ä¸?SOAPElement 的内定wƒ½ä¼šè¢«‹‚€ç´¢ã€‚目前，只有 IBM WebSphere] Application Server (Application Server) 支持˜q™äº›ä»£ç åQˆè¯·å‚阅参考资æ–?/a>åQ‰ã€?然而，如果您移é™?IBM SOAPElementåQŒé‚£ä¹ˆæ‚¨ž®±å¯ä»¥åœ¨ä»ÖM½•åº”用服务器上使用˜q™äº›ä»£ç ã€‚IBM SOAPElement 内置的性能优化也适用äº?Application Serverã€?/p>

每一ä¸?SOAPElement 都ä‹Éç”?Dom4j 来读取、解析和转换。Dom4j 是一¿Uåœ¨å†…存中表½C?XML 树的对象模型。Dom4j 提供了一¾l„易于ä‹É用的 APIåQŒä»Žè€Œäؓ我们提供了一整套强大的功能来处理、操作或定位 XMLåQŒä‹Éç”?XPath å’?XSLT ˜q›è¡Œå·¥ä½œåQŒä»¥åŠä¸Ž SAXã€? JAXP、DOM 集成ã€?/p>

除了可以使用ä»ÀL„çš?XML 解析器外åQŒDOM4J ˜q˜å…è®æ€‹É用ä“Q意的 SAX 解析器，为实现更好的性能åQŒè¿˜å…è®¸ä½¿ç”¨æ‰€æœ‰æ ‡å‡†çš„ XSLT 转换器ã€? 转换被用来析取发送给 Web Service Appender 的客æˆïL«¯ LoggingEvent 的元素ã€?/p>

如果您允è®æ€‹Éç”?SOAPElementåQŒé‚£ä¹ˆå°±éœ€è¦åœ¨ä»£ç ä¸­ç»´æŒæœ€å¤§é™åº¦çš„灉|´»æ€§ã€‚Web Service Appender 服务可以被修改，以支持所有发送给服务çš?XMLã€?

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输出

下面的示例展½CÞZº† Web Service Appender 的可能的输出åQ?/p>

INFO [WebContainer : 0] ejb.LogAppenderBean (log:?) :: [1111513482641:OO7-64BIT/9.48.114.183:main]LoggingSample instantiation...

OO7-64BIT/9.48.114.183 是机器名å’?IP 地址åQŒè€?main 是日志所在处的方法名ã€?/p>

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¾l“束è¯?/span>

Web Service Appender 是将日志集中到某一位置的基本工兗÷€‚ç”±äº?Web Service Appender æ˜?Log4j çš? Appender ¾cȝš„子集åQŒå› è€Œé…¾|®å’Œä½¿ç”¨ Appender 都非常简单易懂。您可以修改 Log4j 的属性文ä»Óž¼Œ˜q™æ ·åQŒä‹Éç”?Log4j 的现有应用程序和服务ž®±å¯ä»¥é©¬ä¸Šä‹Éç”?Web Service Appenderã€?/p>

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