我有演示示例CeConnection.java类，可从 IBM 站点 ( http://www-01.ibm.com/support/docview.wss?uid=swg24028788 ) 获得，您可以在消息顶部找到此类的列表。
因此，我的 webapp 使用单个用户与 Content Engine 通信（是的，单个 'ce_user' 和 'passw123'）。CeConnection您能否解释一下在我的 Vaadin webapp 中为每个用户会话使用此类的良好做法和好方法（vaadin 的入口点 - AppMain.java 类可以有CeConnection字段）。
以下哪种方法是可以的？
1. When the webapp starts I establish connection:
void init() { // this is vaadins entry point
ceConnection = new CeConnection();
ceConnection.establishConnection(...);
}
OR
2. Create new CeConnection for every request to Content Engine. like:
Document getDoc(String id) {
CeConnection ceConnection = new CeConnection(...)
try {
ceConnection.establish(); // (contains UserContext.pushSubject)
...get data from CE....
} finally {
ceConenction.logofMethod(); (contains UserContext.popSubject)
}
}
谢谢！
/**
IBM grants you a nonexclusive copyright license to use all programming code
examples from which you can generate similar function tailored to your own
specific needs.
All sample code is provided by IBM for illustrative purposes only.
These examples have not been thoroughly tested under all conditions. IBM,
therefore cannot guarantee or imply reliability, serviceability, or function of
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without any warranties of any kind.
The implied warranties of non-infringement, merchantability and fitness for a
particular purpose are expressly disclaimed.
� Copyright IBM Corporation 2007, ALL RIGHTS RESERVED.
*/
package cesample;
import java.util.Iterator;
import java.util.Vector;
import javax.security.auth.Subject;
import com.filenet.api.collection.ObjectStoreSet;
import com.filenet.api.core.Connection;
import com.filenet.api.core.Domain;
import com.filenet.api.core.Factory;
import com.filenet.api.core.ObjectStore;
import com.filenet.api.util.UserContext;
/**
* This object represents the connection with
* the Content Engine. Once connection is established
* it intializes Domain and ObjectStoreSet with
* available Domain and ObjectStoreSet.
*
*/
public class CEConnection
{
private Connection con;
private Domain dom;
private String domainName;
private ObjectStoreSet ost;
private Vector osnames;
private boolean isConnected;
private UserContext uc;
/*
* constructor
*/
public CEConnection()
{
con = null;
uc = UserContext.get();
dom = null;
domainName = null;
ost = null;
osnames = new Vector();
isConnected = false;
}
/*
* Establishes connection with Content Engine using
* supplied username, password, JAAS stanza and CE Uri.
*/
public void establishConnection(String userName, String password, String stanza, String uri)
{
con = Factory.Connection.getConnection(uri);
Subject sub = UserContext.createSubject(con,userName,password,stanza);
uc.pushSubject(sub);
dom = fetchDomain();
domainName = dom.get_Name();
ost = getOSSet();
isConnected = true;
}
/*
* Returns Domain object.
*/
public Domain fetchDomain()
{
dom = Factory.Domain.fetchInstance(con, null, null);
return dom;
}
/*
* Returns ObjectStoreSet from Domain
*/
public ObjectStoreSet getOSSet()
{
ost = dom.get_ObjectStores();
return ost;
}
/*
* Returns vector containing ObjectStore
* names from object stores available in
* ObjectStoreSet.
*/
public Vector getOSNames()
{
if(osnames.isEmpty())
{
Iterator it = ost.iterator();
while(it.hasNext())
{
ObjectStore os = (ObjectStore) it.next();
osnames.add(os.get_DisplayName());
}
}
return osnames;
}
/*
* Checks whether connection has established
* with the Content Engine or not.
*/
public boolean isConnected()
{
return isConnected;
}
/*
* Returns ObjectStore object for supplied
* object store name.
*/
public ObjectStore fetchOS(String name)
{
ObjectStore os = Factory.ObjectStore.fetchInstance(dom, name, null);
return os;
}
/*
* Returns the domain name.
*/
public String getDomainName()
{
return domainName;
}
}
编辑：添加
我想知道，如果两个客户端几乎同时调用 servlet 方法，而一个客户端首先调用 PopSubject，会发生什么？com.filenet.api.util.UserContext 类是线程安全的吗？
小服务程序方法：
public String getDocumentNumber(String id) {
UserContext.get().pushSubject(mySubject);
try {
....
....
....
....
} finally {
UserContext.get().popSubject();
}
}
//com.filenet.api.util.UserContext 类
public static UserContext get() {
UserContext cntx = (UserContext)tl.get();
if(cntx == null) {
cntx = new UserContext();
tl.set(cntx);
}
return cntx;
}
public synchronized void pushSubject(Subject sub) {
if(sub == null) {
throw new EngineRuntimeException(ExceptionCode.E_NULL_OR_INVALID_PARAM_VALUE, "Subject");
} else {
this.subjects.add(sub);
}
}
public synchronized Subject popSubject() {
return this.subjects.isEmpty()?null:(Subject)this.subjects.remove(this.subjects.size() - 1);
}