我的工作是使用 Servlet 编写一种 Web 服务适配器，然后调用适配器 EJB（SOAP Web 服务），后者又调用现有的服务方法（也是 EJB）。现有架构基于 EJB 2.0，我暂时无法更改。外部客户应该直接访问 Servlet 而不是 webservice 类。原因是需要使用 HTTPRequest 中的信息进行一些预处理（从证书或 HTTP Header 中获取和映射用户 ID）。因此，Servlet 对 doPost() 方法做出反应，执行预处理，如解析和编组 SOAP XML 数据，然后调用适配器 EJB（无状态会话 Bean），更准确地说是 web 服务方法，然后将触发不同的现有服务方法EJB。到目前为止，在 EJB 需要现有的 Session 之前，这种方法运行良好。SessionContext，就像在以下处理事务回滚的情况下一样：
protected void preventTransactionRolledBackException() {
if (this.getSessionContext().getRollbackOnly()) {
this.getSessionContext().setRollbackOnly();
}
}
在我的设置中，SessionContext 始终为空。由于整个应用程序已经相当复杂，我尝试发布一个仅使用 Servlet 和一个 EJB 的简化设置，希望我不会排除相关的内容。系统：WebSphere 应用服务器 8.5
小服务程序：
public class NewZekEclsServiceServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String operation = null;
response.setContentType("text/xml");
try {
PrintWriter out = response.getWriter();
// Get Header data
// Get Attribute data
// Get Body data:
InputStream body = request.getInputStream();
String xml = IOUtils.toString(body, "UTF-8");
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
docBuilderFactory.setNamespaceAware(true); // required as several namespaces might be used
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse(new InputSource(new StringReader(xml)));
operation = getOperation(doc); // method which scans the xml to retrieve the correct operation to use.
if (operation.equalsIgnoreCase("Ping")) {
// Calling the Adapter Bean:
EclsTestBeanBean eclsTestBean = new EclsTestBeanBean();
eclsTestBean.ejbCreate();
PingIn pingIn = new PingIn();
PingOut pingOut = eclsTestBean.ping(pingIn);
String xmlString = convertEclsObjectToSOAPString(pingOut);
out.print(xmlString);
}
}
}
}
EJB（由 Rational Application Developer 9.0 生成）：
/**
* Bean implementation class for Session Bean: EclsTestBean
*
* @ejb.bean
* name="EclsTestBean"
* type="Stateless"
* jndi-name="ejb/ch/zek/ecls/EclsTestBeanHome"
* view-type="remote"
* transaction-type="Bean"
*
* @ejb.home
* remote-class="ch.zek.ecls.EclsTestBeanHome"
*
* @ejb.interface
* remote-class="ch.zek.ecls.EclsTestBean"
*
*/
public class EclsTestBeanBean implements javax.ejb.SessionBean {
private Log log = LogFactory.getLog(EcodeAbfragenAction.class);
private SessionContext mySessionCtx;
public SessionContext getSessionContext() {
return mySessionCtx;
}
public void setSessionContext(SessionContext ctx) {
mySessionCtx = ctx;
}
public void ejbCreate() throws CreateException {}
public void ejbActivate() {}
public void ejbPassivate() {}
public void ejbRemove() {}
/**
* Basic ping service for ECLS
* @param parameters
* @return
* @throws PingEntityNotFoundException
* @throws PingPermissionException
* @throws PingSystemException
*/
public ch.zek.ecls.PingOut ping(ch.zek.ecls.PingIn parameters) throws java.rmi.RemoteException, ch.zek.ecls.PingPermissionException, ch.zek.ecls.PingEntityNotFoundException, ch.zek.ecls.PingSystemException {
PingOut pingOut = new PingOut();
String pingAnswer = "Ping_ECLS_v1";
String adapter = "";
String operation = "";
Parameter[] msgParams = new Parameter[1];
String eclsEnvironment = "TEST";
pingAnswer += "_" + eclsEnvironment;
logAvailableEjbs();
try {
if (mySessionCtx != null) { // Why can it be null at all?
log.debug("mySessionCtx: " + mySessionCtx.getContextData());
} else {
log.debug("mySessionCtx was null");
InitialContext ic = new InitialContext();
mySessionCtx = (SessionContext) ic.lookup("java:comp/env/sessionContext"); // gives error: javax.naming.NameNotFoundException: Name "comp/env/sessionContext" not found in context "java:".
System.out.println("mySessionCtx: " + mySessionCtx);
}
} catch (Exception e) {
e.printStackTrace();
}
// creating the SOAP data... not relevant for the problem.
msgParams[0] = new Parameter();
msgParams[0].setValue(pingAnswer);
SystemMessage systemMessage = new SystemMessage();
systemMessage.setCode("OK");
systemMessage.setMessage("Ping");
systemMessage.setParameter(msgParams);
pingOut.setSystemMessage(systemMessage);
return pingOut;
}
/**
* ONLY USED DURING DEVELOPMENT:
* Helper method to print "accessible" EJBs.
*/
protected void logAvailableEjbs() {
try {
//Get the Initial Context for the JNDI lookup for a local EJB
InitialContext ic = new InitialContext();
NamingEnumeration<NameClassPair> list;
String level = "";
String name = "";
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
level = "ejb";
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
level = "java:comp";
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
level = "java:comp/env";
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
/*
level = "java:comp/env/ejb"; // Throws Error!
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
*/
level = "java:global";
list = ic.list(level);
while (list.hasMore()) {
name = list.next().getName();
System.out.println(level + "/" + name);
}
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我们正在使用 SoapUI 工具 ( http://www.soapui.org ) 测试设置。同样，对于简单的 Ping() 服务，我们得到了正确的结果，但是一旦需要与会话相关的内容，它就会失败。
当然我做了一些研究，特别有趣的是这个链接： How to get SessionContext in JBOSS 这也指的是：http: //javahowto.blogspot.co.uk/2006/06/4-ways-to-get-ejbcontext-在-ejb-3.html
关于 EJB 生命周期：docs.oracle.com/cd/E13224_01/wlw/docs100/guide/ejb/session/conSessionBeanLifeCycle.html J2EE-Tutorial：docs.oracle.com/javaee/6/tutorial/doc/gipss.html# gipsx（抱歉，不能发布超过 2 个链接...）
但正如代码中所述，我无法访问 java:comp/env/ejb/sessionContext。嗯...甚至没有 java:comp/env/ejb。我编写了一个脏帮助器方法来查看 EJB 实际可访问的内容并获得以下输出：
SystemOut O /jta
SystemOut O /eis
SystemOut O /cell
SystemOut O /thisNode
SystemOut O /DefaultDatasource
SystemOut O /services
SystemOut O /jdbc
SystemOut O /servername
SystemOut O /com.ibm.websphere.ejbcontainer
SystemOut O /com
SystemOut O /zek
SystemOut O /wm
SystemOut O /ejb
SystemOut O /Increment
SystemOut O /tm
SystemOut O ejb/ivtEJBObject
SystemOut O ejb/ch
SystemOut O ejb/mgmt
SystemOut O java:comp/ValidatorFactory
SystemOut O java:comp/TransactionSynchronizationRegistry
SystemOut O java:comp/ORB
SystemOut O java:comp/Validator
SystemOut O java:comp/UserTransaction
SystemOut O java:comp/env
SystemOut O java:comp/BeanManager
SystemOut O java:comp/websphere
SystemOut O java:comp/HandleDelegate
SystemOut O java:global/com.ibm.ws.AppNameSpaces
SystemOut O java:global/NewZekEar
SystemOut O java:global/SchedulerCalendars
SystemOut O java:global/DefaultApplication
SystemOut O java:global/cell
SystemOut O java:global/query
SystemOut O java:global/ManagementEJB
SystemOut O java:global/ivtApp
我也尝试使用注释：
@Resource
private SessionContext mySessionCtx;
或以不同的方式设置交易类型：
transaction-type="Container"
没有任何帮助。我知道应该自动创建 SessionContext 。但如果不是 - 必须创建一个新选项的哪个选项？进一步的问题：servlet 还“创建”了一个我可以访问的会话（request.getSession()），但这是不同的（HTTPSession）。我想我不能共享或“转换”这个会话对象到会话 Bean？