我在使用 GlassFish 和 SAP JCo 连接器 (sapjco3.jar) 时遇到问题。
我在 J2EE 应用程序 (jwm.ear) 启动时加载它，并在第一次需要连接到 SAP 时将其包装在单例中进行初始化。
问题是这个 jar 始终在内存中保持初始化状态，如果我需要更改单个参数，我需要重新启动 glassfish 来卸载初始化的连接。停止或取消部署应用程序不会卸载 sapjco.jar，并且应用程序的进一步重新部署永远不会获得新的连接参数，第一次初始化将保留到 GlassFish 重新启动。
有人知道如何卸载或重新初始化这个库吗？最好即使不重新部署应用程序，第一次激活应用程序时，我都会有对 jcoProvider 的引用，下一次激活会获得对 jcoProvider 的空引用，但 jcoProvider 会继续在内存中使用初始值进行实例化。
问候!
注释: GlassFish在Windows 2008服务器中是2.1版本，jdk是1.6.0.14 sapjco3.jar 和 sapjco3.dll 复制到\domains\domain1\lib\ext 并且是 SAP java 连接器的版本 3。
单例获取 SAP 连接:
package es.grupotec.ejb.SAP;
import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoException;
import com.sap.conn.jco.ext.DestinationDataProvider;
import com.sap.conn.jco.ext.Environment;
import es.grupotec.ejb.util.ConexionSAPException;
import java.util.Properties;
public final class SAP {
private static String SAP_SERVER = "JWM";
private static SAP instance = null;
private static JCOProvider jcoProvider = null;
private SAP() {
// Exists only to defeat instantiation.
}
// Get SAP connection
public static synchronized JCoDestination getDestination() throws ConexionSAPException {
JCoDestination jcoDestination = null;
if (Environment.isDestinationDataProviderRegistered()) {
try {
jcoDestination = JCoDestinationManager.getDestination(SAP_SERVER);
return jcoDestination;
} catch (JCoException ex) {
throw new ConexionSAPException(ex.getMessage());
}
}
// Create new connection
if(jcoProvider == null) init();
// Get connection
try {
jcoDestination = JCoDestinationManager.getDestination(SAP_SERVER);
return jcoDestination;
} catch (JCoException ex) {
throw new ConexionSAPException(ex.getMessage());
}
}
// Initialize connection to SAP
public static synchronized void init() throws ConexionSAPException {
SAPVO sap = new SAPVO();
Properties properties = new Properties();
if(jcoProvider == null) {
// Get SAP config from database
try {
sap = SAPDAO.getSAPConfig();
} catch (Exception ex) {
throw new ConexionSAPException(ex.getMessage());
}
// Create connection object
jcoProvider = new JCOProvider();
}
properties.setProperty(DestinationDataProvider.JCO_ASHOST, sap.getJCO_ASHOST());
properties.setProperty(DestinationDataProvider.JCO_SYSNR, sap.getJCO_SYSNR());
properties.setProperty(DestinationDataProvider.JCO_CLIENT, sap.getJCO_CLIENT());
properties.setProperty(DestinationDataProvider.JCO_USER, sap.getJCO_USER());
properties.setProperty(DestinationDataProvider.JCO_PASSWD, sap.getJCO_PASSWD());
properties.setProperty(DestinationDataProvider.JCO_LANG, sap.getJCO_LANG());
try {
jcoProvider.changePropertiesForABAP_AS(properties);
} catch (Exception e) {
throw new ConexionSAPException(e.getMessage());
}
}
public static synchronized void change(SAPVO sap) throws ConexionSAPException {
Properties properties = new Properties();
// If connection is null create a new one
if(jcoProvider == null) jcoProvider = new JCOProvider();
properties.setProperty(DestinationDataProvider.JCO_ASHOST, sap.getJCO_ASHOST());
properties.setProperty(DestinationDataProvider.JCO_SYSNR, sap.getJCO_SYSNR());
properties.setProperty(DestinationDataProvider.JCO_CLIENT, sap.getJCO_CLIENT());
properties.setProperty(DestinationDataProvider.JCO_USER, sap.getJCO_USER());
properties.setProperty(DestinationDataProvider.JCO_PASSWD, sap.getJCO_PASSWD());
properties.setProperty(DestinationDataProvider.JCO_LANG, sap.getJCO_LANG());
try {
jcoProvider.changePropertiesForABAP_AS(properties);
} catch (Exception e) {
throw new ConexionSAPException(e.getMessage());
}
}
// Prevent instantiation by clone
@Override
public Object clone() throws CloneNotSupportedException {
throw new CloneNotSupportedException();
}
}
JCo 提供者实现:
package es.grupotec.ejb.SAP;
import com.sap.conn.jco.ext.DestinationDataEventListener;
import com.sap.conn.jco.ext.DestinationDataProvider;
import com.sap.conn.jco.ext.Environment;
import es.grupotec.ejb.util.ConexionSAPException;
import java.util.Properties;
public class JCOProvider implements DestinationDataProvider {
private String SAP_SERVER = "JWM";
private DestinationDataEventListener eventListener;
private Properties ABAP_AS_properties;
public JCOProvider(){
}
public JCOProvider(SAPVO sap){
ABAP_AS_properties = new Properties();
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_ASHOST, sap.getJCO_ASHOST());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_SYSNR, sap.getJCO_SYSNR());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_CLIENT, sap.getJCO_CLIENT());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_USER, sap.getJCO_USER());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_PASSWD, sap.getJCO_PASSWD());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_LANG, sap.getJCO_LANG());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_POOL_CAPACITY, sap.getJCO_POOL_CAPACITY());
ABAP_AS_properties.setProperty(DestinationDataProvider.JCO_PEAK_LIMIT, sap.getJCO_PEAK_LIMIT());
try {
if (!Environment.isDestinationDataProviderRegistered())
Environment.registerDestinationDataProvider(this);
else changePropertiesForABAP_AS(ABAP_AS_properties);
} catch (Exception ex) {
String msg = ex.getMessage();
}
}
@Override
public Properties getDestinationProperties(String name) {
if (name.equals(SAP_SERVER) && ABAP_AS_properties!=null) return ABAP_AS_properties;
else return null;
}
@Override
public boolean supportsEvents() {
return true;
}
@Override
public void setDestinationDataEventListener(DestinationDataEventListener eventListener) {
this.eventListener = eventListener;
}
public void changePropertiesForABAP_AS(Properties properties) throws ConexionSAPException {
try {
if (!Environment.isDestinationDataProviderRegistered()) {
if (ABAP_AS_properties == null) ABAP_AS_properties = properties;
Environment.registerDestinationDataProvider(this);
}
if (properties == null) {
if (eventListener != null) eventListener.deleted(SAP_SERVER);
ABAP_AS_properties = null;
} else {
ABAP_AS_properties = properties;
if (eventListener != null) eventListener.updated(SAP_SERVER);
}
} catch (Exception ex) {
throw new ConexionSAPException(ex.getMessage());
}
}
}
最佳答案
您的问题可能与这里涉及一些 native 代码有关。对于 JCo 3 来说也是如此。虽然 JCo 3 不再使用 native RFC 库，但它仍然需要 JNI 与 CPIC 层通信。
让 JVM 卸载 native 库是一项极其令人沮丧的工作。 JNI 规范规定，当与提供实现的类关联的类加载器被卸载时， native 库将被卸载，但在 JVM 中尝试强制类加载器卸载实际上是不可能的。
如果您的 EAR 文件包含 sapjco3.jar，每次重新加载代码时都会重新加载它。这很可能会导致异常，因为 native 库无法加载多次，并且几乎无法卸载 native 代码。因此，您可能会考虑将 sapjco3.jar 放在 J2EE 容器之外，让 J2EE 引擎在启动时加载该库一次，而不是将其放入 EAR 中并一遍又一遍地重新加载。
关于java - SAP JCo 连接器在 GlassFish v2.1 中永久加载(无法卸载)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1899888/