SAP Community - SAP Java Connector (JCo)

SAP JCo initializer error

2024-08-27T02:06:54.861000+02:00

Hi All,

I'm trying to run a function module from Eclipse but I'm getting the following initializer errors:

Execute failed: JCo initialization failed with java.lang.UnsatisfiedLinkError ...KNIME\configuration\org.eclipse.osgi\705\0\.cp\sapjco3.dll: Can't find dependent libraries

Execute failed: Could not initialize class com.sap.conn.jco.rt.JCoRuntimeFactory

I'm using Windows 11, running on Java 17 and I've already installed the Microsoft Visual C++ 2015-2022 Redistributable (x64). I've also tried putting the JAR and the dll in the same directory but it didn't work.

Any help would be highly appreciated.

Listener error in RFC TCP/IP

2024-10-23T01:35:17.023000+02:00

I created an RFC type T, TCP/IP connection
however, when generating the connection for the connector with the Non SAP partner, this error message appeared

APPROVAL ERROR - 3.133.1 [JCoServerControllerThread] [ThrowableListener.java:20] Error in sap lister 709757/0|com.sap.conn.jco.JCoException: Server startup failed at Tue Oct 22 16:28:50 BRT 2024. 709757/0|This is caused by a) erroneous server configurations, b) the backend system has been shut down, c) network issues. Will attempt the next boot in 128 seconds. 709757/0|Unable to start server: Connection to SAP gateway failed 709757/0| Connection parameters: PROGID="......

No RFC authorization for function module RFCPING.

2024-11-04T17:37:27.645000+01:00

Hi!

I need to know how to resolve the error that displays the RFCPING authorization error message?

2024-11-02 08:24:14,052 ERROR HOMOLOGACAO - 3.133.1 [main] [JCoServerDeployment.java:122] erro ao iniciar o SAP server
com.sap.conn.jco.JCoException: Server default repository destination CLIENT_POOL is invalid: Initialization of repository destination CLIENT_POOL failed: No RFC authorization for function module RFCPING. on 10.xx.xx.xx sysnr 00
at com.sap.conn.jco.rt.DefaultServer.update(DefaultServer.java:240)
at com.sap.conn.jco.rt.DefaultServer.<init>(DefaultServer.java:117)
at com.sap.conn.jco.rt.DefaultServerManager$DefaultServerFactory.createServer(DefaultServerManager.java:412)
at com.sap.conn.jco.rt.DefaultServerManager.getServer(DefaultServerManager.java:104)
at com.sap.conn.jco.rt.StandaloneServerFactory.update(StandaloneServerFactory.java:362)
at com.sap.conn.jco.rt.StandaloneServerFactory.getServerInstance(StandaloneServerFactory.java:175)
at com.sap.conn.jco.server.JCoServerFactory.getServer(JCoServerFactory.java:105)
at com.mastersaf.dfe.connectores.JCoServerDeployment.createJCoServer(JCoServerDeployment.java:118)
at com.mastersaf.dfe.connectores.JCoServerDeployment.createAndConfigureJCoServer(JCoServerDeployment.java:80)
at com.mastersaf.dfe.connectores.JCoServerDeployment.createRFCServer(JCoServerDeployment.java:66)
at com.mastersaf.dfe.connectores.JCoServerDeployment.onDeploy(JCoServerDeployment.java:62)
at com.mastersaf.integrator.core.IntegratorServer.runAllDeploymentListeners(IntegratorServer.java:64)
at com.mastersaf.integrator.core.IntegratorServer.start(IntegratorServer.java:58)
at com.mastersaf.integrator.core.IntegratorServer.main(IntegratorServer.java:41)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

Error message in the external connector Jco with SAP

2024-11-06T14:04:13.840000+01:00

I am facing this type of error when connecting the SAP Destination RFC with Java. The Java consultant is encountering this error in the command line.
What could this be?
We need to resolve this issue as soon as possible. Best regards!!

2024-11-05 22:56:59,268 WARN HOMOLOGACAO - 3.133.1 [main] [IntegradorCamelContext.java:94] JMX do Broker disabled!

2024-11-05 22:56:59,297 WARN HOMOLOGACAO - 3.133.1 [main] [BrokerService.java:2171] Memory Usage for the Broker (1024mb) is more than the maximum available for the JVM: 512 mb - resetting to 70% of maximum available: 358

2024-11-05 22:56:59,528 WARN HOMOLOGACAO - 3.133.1 [main] [BrokerService.java:2128] Store limit is 102400 mb (current store usage is 12 mb). The data directory: /data/ConectorSAP/ConectorSAP3.133.1/activemq-data/ConectorDfeBroker/KahaDB only has 101011 mb of usable space. - resetting to maximum available disk space: 101011 mb

2024-11-05 22:57:29,785 ERROR HOMOLOGACAO - 3.133.1 [JCoServerThread-1] [ThrowableListener.java:20] Erro no lister do sap

com.sap.conn.jco.JCoException: CPIC-CALL: SAP_CMACCPTP3 on convId:

LOCATION SAP-Gateway on host de4.xxx... / sapgw00

ERROR registration of tp RFC_MSAFDFE from host 10.xx.xxx.xx.. not

allowed

TIME Wed Nov 6 09:57:29 2024

RELEASE 777

COMPONENT SAP-Gateway

VERSION 2

RC 720

MODULE /bas/777_REL/src/krn/si/gw/gwxxrd.c

LINE 4401

COUNTER 1207

at com.sap.conn.jco.rt.MiddlewareJavaRfc.generateJCoException(MiddlewareJavaRfc.java:626)

at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcServer.listen(MiddlewareJavaRfc.java:2537)

at com.sap.conn.jco.rt.DefaultServerWorker.dispatch(DefaultServerWorker.java:275)

at com.sap.conn.jco.rt.DefaultServerWorker.loop(DefaultServerWorker.java:356)

at com.sap.conn.jco.rt.DefaultServerWorker.run(DefaultServerWorker.java:232)

at java.base/java.lang.Thread.run(Thread.java:840)

Caused by: com.sap.conn.rfc.exceptions.RfcException: CPIC-CALL: SAP_CMACCPTP3 on convId:

LOCATION SAP-Gateway on host de4.xxx... / sapgw00

ERROR registration of tp RFC_MSAFDFE from host 10.xx.xxx.xxx not

allowed

TIME Wed Nov 6 09:57:29 2024

RELEASE 777

COMPONENT SAP-Gateway

VERSION 2

RC 720

MODULE /bas/777_REL/src/krn/si/gw/gwxxrd.c

LINE 4401

COUNTER 1207

at com.sap.conn.rfc.engine.RfcIoOpenCntl.RfcListen(RfcIoOpenCntl.java:2356)

at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcServer.listen(MiddlewareJavaRfc.java:2503)

... 4 common frames omitted

Caused by: com.sap.conn.rfc.exceptions.RfcIoException: CPIC-CALL: SAP_CMACCPTP3 on convId:

LOCATION SAP-Gateway on host de4.goldwind.com.cn / sapgw00

ERROR registration of tp RFC_MSAFDFE from host 10.xx.xxx... not

allowed

TIME Wed Nov 6 09:57:29 2024

RELEASE 777

COMPONENT SAP-Gateway

VERSION 2

RC 720

MODULE /bas/777_REL/src/krn/si/gw/gwxxrd.c

LINE 4401

COUNTER 1207

at com.sap.conn.rfc.engine.RfcIoOpenCntl.ab_rfclisten(RfcIoOpenCntl.java:1389)

at com.sap.conn.rfc.engine.RfcIoOpenCntl.RfcListen(RfcIoOpenCntl.java:2352)

... 5 common frames omitted

2024-11-05 22:57:29,787 ERROR HOMOLOGACAO - 3.133.1 [JCoServerThread-1] [ThrowableListener.java:21] Error occured on RFC_MSAFDFE connection 3-10.xxxx.xxxx.|sapgw00|RFC_MSAFDFE

2024-11-05 22:57:29,787 ERROR HOMOLOGACAO - 3.133.1 [JCoServerThread-2] [ThrowableListener.java:20] Erro no lister do sap

com.sap.conn.jco.JCoException: CPIC-CALL: SAP_CMACCPTP3 on convId:

JAVA Connector 3.1

2024-12-09T06:14:30.644000+01:00

Hello All ,

Can we able to multiple abap system (DEV/QUA/PRE-PROD) using single JAVA connector (3.1)

If yes , Kindly share configuration steps or standard guide for the same ?

Regards ,

SAI K

Hi there, I have a challenge while integrating SAP JCo (3.1.10) into a Maven. Naming not allowed

2024-12-12T14:21:07.105000+01:00

My issue is integrating SAP JCo (version 3.1.10) into a Maven-based Java project, specifically for creating a custom NiFi processor.

Despite attempts to use Maven's maven-dependency-plugin with configurations like stripVersion or destFileName to rename the jar back to sapjco3.jar during the build process, the issue persists. This causes the following runtime error:

java.lang.ExceptionInInitializerError: Illegal JCo archive "sapjco3-3.1.10.jar". It is not allowed to rename or repackage the original archive "sapjco3.jar".

QUESTIONS:

1. Maven Integration: Is there an officially recommended approach to integrate SAP JCo into Maven projects while following SAP's archive naming restrictions?
2. Runtime Compliance: Are there specific runtime configurations, environment variables, or Java options that could help resolve this issue?
3. Artifact Packaging: How should the sapjco3.jar be handled in scenarios where it needs to be included as part of a deployable archive (e.g., NiFi’s NAR format)?
4. Future Enhancements: Given the challenges of using JCo with Maven, are there any plans for SAP to release Maven-compatible artifacts or documentation addressing these issues?

I can not create a settlement rule for some service order with Java Connector

2024-12-19T14:47:09.981000+01:00

Hello colleagues ,

I can not create a settlement rule for some service order with Java Connector but still able to do it with the Apab Work Bench...

//Java

JCoTable tableRange2 = fuba.getTableParameterList().getTable("IT_SRULE");

tableRange2.appendRow();

tableRange2.setRow(0);

tableRange2.setValue("PERCENTAGE","100") ;

tableRange2.setValue("SETTL_TYPE","PER");

tableRange2.setValue("COSTCENTER",xxxSomeNumber,ber );

tableRange2.setValue("LFDNR","1");

The Parameters look the same...but still getting the messages in Java-> the receiver could not be calculeted(aclually - german message below)

Programmfehler: Objektart des Empfaengers nicht ermittelbar

Fehler beim Bearbeiten der BAPI-Methoden

Could anybody help?

Thanks!

Irina

Cannot find BAPI in Action.

2025-01-13T07:57:56.756000+01:00

Can Anyone tell me the solution regarding how to call BAPI

Query on j2ee_admin user id change in SAP SOLMAN 7.2 after system copy

2025-01-22T05:59:10.232000+01:00

Dear All,

We installed the Solution Manager 7.2 development system and refreshed data from the production Solution Manager system.

Our Database is MAXDB

ABAP stack we did backup /restore database
JAVA stack we did system copy export of JAVA stack production database and system copy import in development system

We need to create a new user called j2ee_adm_dev, as a copy of j2ee_adm_prd.
After creating the user ID j2ee_adm_dev, could you please specify the areas/locations in SAP JAVA (like SAP NWA, Configtool) where updates are required? (Replace j2ee_adm_prd with j2ee_adm_dev)
Once the changes are completed in SAP NWA, we will lock the j2ee_adm_prd user.

Note :

1. We will keep the same sapjsf and j2ee_guest users along with their passwords as in the Production system, (there will be no change in user name and its passwords)

2. We will reconfigure Managed system configuration in Development system

Regards
Appuru

Communicate from SAP Public Cloud to Java Application (Jco Server) via WebSocketRFC Problem

2025-01-28T14:28:12.902000+01:00

Hello everybody,

i am having a problem while trying to call a outbound service from the SAP Public Cloud to a external JCo WebSocketRFC Server instance.

My JCo WebSocketRFC server is running on a VM that is exposed to the internet on port 8080.

In the SAP Public Cloud i have already configured the communication system where i have just entered the "Host Name" of my VM and set the Authentification Method in the "Users for Outbound Communication" to None since i do not need the authentification for the tests.

I have also configured a communication agreement for the communication system

On the Eclipse ADT side i have a communication scenario that looks like this:

with the corresponding outbound service

Now, when i try to call the outbound service from SAP Public Cloud ABAP with the corresponding code:

like described by SAP i get the following error

Anyone has an idea why this fails? Dis anyone made a scenario like this before? - to communicate from the SAP Public Cloud to a external server program? I have only found tutorials how to communicate with on prem systems.

The JcoTrace for the server says the following (i have replaced the real IP with "hostname" in the screenshot)

obviously the handshake cannot be completed. I am trying to connect to the server withot any authentification (i have set the communication scenario to "Unauthentifiacted" and i have startet the Jco server without any p12 files - jco.server.use_tls=0).

Server props:

@MarkusTolksdorf @simon_luser Thanks for your reply, i have added the Trace from the Jco. Could the problem be the missing authorisation?

Outbound communication from SAP Public cloud to a Websocket RFC Server in a fenced customer network

2025-03-05T12:14:51.564000+01:00

Hello everybody,

is there any possibility to call a outbound service from SAP Public Cloud to a Websocket RFC server that is running in a fenced company network ? I have already called that Websocket RFC server with success but in that scenario the server must be accessible from the internet.

Maybe there is any way to use a VPN tunnel to get that connection done? Maybe even not with Websocket RFC if that should not be possible but with HTTP or even thru BTP like:

SAP Public Cloud -> BTP (some destination or tunnel) -> external program in a fenced company network (server).

Can such scenario be accomplished at all or is it not possible?

Greetings!

@simon_luser , @Ulrich_Schmidt1 thanks for your replies - update 14.03.25 - in the meanwhile i have installed the Cloud Connector on the machine where my WebSocket RFC Server is running (inside a fenced company network). Sadly i still wasn't able to establish a connection. For now i am not sure if this can be done using the Cloud Connector combined with a WebSocket RFC call from SAP public cloud. The problem is, as i suppose, that in the cloud connector there is no option for a RFC protocoll while selecting the target system "Non-SAP" that is my WebSocket RFC server. the possible option are:

Therefore i have selected the TCP protocol that at least does "see" the WebSoclet RFC server running on its port

but with that configuration i get no connection to the server. In the monitor view i do not see any throughput for the configured Cloud Connector.

I have also found a blog entry from Thomas Weiss (from 2021 - maybe its outdated?)

https://community.sap.com/t5/technology-blogs-by-sap/websocket-rfc-rfc-for-the-internet/ba-p/13502531

that is saying the following:

So i suppose for the scenario:

--> SAP Public Cloud (embedded steampunk) to WebSocket RFC Server in a fenced company network some different communication type must be used.

Or maybe i am doing something wrong? any ideas?

Greetings!

SAP JCO 3.1.11 > Last Java supported version ?

2025-03-17T11:58:45.524000+01:00

Hello,

I contact you because we are installing a SAP JCO 3.1.11 on some our Windows server.

I checked the following link : SAP Java Connector
And this SAP Note : 2786882 - SAP JCo 3.1 release and support strategy

I saw the last Java version supported is 21, but there are a lot of new versions of Java available now, 22 and 23...
Is it mandatory to use Java 21 or can we use the most recent version ?

Regards,

Florent Palcy

AR Company

Does SAP JCo hold memory if all heavy logic is in ABAP and Java just waits for the result?

2025-05-07T08:50:17.321000+02:00

I'm using SAP Java Connector (JCo 3.x) to call an ABAP remote-enabled function module (FM) from a Java application.

The scenario:

The FM performs heavy processing entirely inside ABAP
Importing/exporting parameters are small (just a few scalars and short messages)
Java uses JCoDestinationManager.getDestination() and calls .execute()
I do not use JCoContext.begin() — so it's a stateless call

The issue:

Despite minimal input/output, our Java process shows large memory spikes
If two JCo calls run concurrently, total memory usage reaches 8 GB and crashes
ABAP logic is confirmed to be memory-heavy (large SELECTs, joins, etc.), but it completes normally when called standalone

Question:

Does JCo hold backend session data or native memory while waiting for the ABAP FM to complete?
Can memory usage grow on the Java side just because of ABAP-side memory, even when nothing large is returned?
What is the best way to avoid memory pressure in this scenario?

Any clarification on JCo behavior or best practices is appreciated.

Error rfc in cloud foundry with jco: There is no SAP Cloud Connector (SCC) connected

2025-05-22T12:07:13.471000+02:00

Hi ,
in my application deployed on SAP BTP Cloud Foundry, I am trying to connect via RFC using the JCo libraries to an on-premise SAP service.
However, I encounter the following error:

Code

failed: There is no SAP Cloud Connector (SCC) connected to your subaccount matching the requested tunnel for subaccount "JCoSingleTenantKyma" and SCC location ID "ENGLAND". Check the configuration on SCC and cloud side. (remote system is [<unknown>])","level":"WARN","SERVER":"main","written_ts":"1747902844351120977","logger":"com.sap.conn.jco","HOST":"8dc4ba91-c82c-4fbc-4dd3-b9dc","written_at":"2025-05-22T08:34:04.350Z","thread":"main","type":"log"}

To clarify:

The destination in SAP BTP successfully passes the connection test with the Cloud Connector.
My application correctly retrieves the destination data and only fails at this call:

Java

JCoDestination destination = JCoDestinationManager.getDestination(destinationName);
System.out.println("Get destination ==>  " + destination.getDestinationID());
destination.ping();

On the Cloud Connector side, the destination is green, so it passes the tests.
There are no discrepancies with the various subaccounts; I have checked the IDs and they match both in SAP BTP and in SCC.

What could be the cause of this?

How to use JCO3 in MII with SSO

2025-07-25T10:31:30.420000+02:00

Switching to JCO3 (due to INT8), but cannot get it to work with SSO, error is "Initialisation of destination XXX failed : connection already closed".

It works fine in non-sso scenario.

Thanks in advance

Nick

JCo Parameters

2025-09-17T11:34:56.856000+02:00

Hello together,

we have connected our SAP ECC System with our WACOS Warehouse Management System via Direkt RFC with SAP JCO.

After switching our quality System to SAP ECS Cloud we had the Problem that the rfc queue in sm58 was only precessing one call every few minutes.

We changed the following parameter jco.server.connection_count from 1 to 40. After that the Performance of processing RFC Calls was much better than before.

But we are not sure if it's enogh to change the parameter up to 40 or if we must rise it higher.

In normal Business we are packing our parcels at nearly 20-25 packing stations. Each parcel needs 2 RFC Calls. In the logging we saw that each call creates up to 5 Connections at one time. So is it ok when we rise the parameter up to 100 oder higher? Or will we get some Problems then?

These parameters were changed additionally:

jco.destination.peak_limit=50

jco.destination.pool_capacity=40

jco.destination.expiration_time=900000

jco.destination.expiration_period=600000

jco.destination.max_get_time=60000

Does anybody have experience with that?

Thanks in advance!

Gunther

如何实时监控(Hana某表的)删除事件 How to runtime-subscribe to deletion events for a ERP table

2025-11-03T10:34:41.252000+01:00

您好, 我们有个安全与容灾项目, 需要实时的监控某些表的删除事件, 以实现对高敏感业务操作的实时预警和自动处理;

现在的问题是: 我们不知道要如何才能订阅到相关ERP表中某行记录的删除事件 (有PrimayKey主键), 希望SAP能提供这方面的方案建议和指导;

We would like to know how to subscribe to deletion events for specific rows in related ERP tables (with a Primary Key). SAP is requested to provide solution suggestions and implementation guidance on this topic.

Download the SAP Java Connector (JCo) as a guest

2025-11-13T09:56:43.365000+01:00

Dear Sir or Madam.

How can I download the SAP Java Connector (JCo) when I am not an SAP customer, but only a guest?
I only got an login with P-Number, bot not an S-User-Account and therefore when trying to download from
https://support.sap.com/en/product/connectors/jco.html
only receive:
"You are not authorized to use this application".

I already tried contacting Support via Chat, but was told I should as here in the community forum.

I am not an SAP Customer and only want to use a third party tool that requires the JCo to integrate with SAP.

Thank you for your help and with kind regards,

Jan S.

JCo RFC Output: Is Sorting or TOP N Selection Possible?

2025-11-25T12:45:43.774000+01:00

Hi experts,

I am calling some SAP standard RFC functions via JCo (for example: SWNC_GET_WORKLOAD_SNAPSHOT) which return large internal tables in the export parameters.

I would like to know whether it is possible to:

Sort the export table in the RFC result (e.g., ORDER BY a specific field), or
Limit the number of rows returned (e.g., TOP 30 records)

Is there any SAP-supported way to sort or limit the entries directly in the RFC call?

Or is the only option to fetch the full table and then perform sorting/limiting on the Java/JCo side?

Any guidance or confirmation from SAP or community experience would be greatly appreciated.

Thanks!

Can any RFCs trigger UPDATE operations?

2025-12-12T13:36:06.823000+01:00

Hello Experts,

We invoke JCo functions and use RFC calls to collect performance metrics. Based on our understanding, these RFCs are read-only in nature. However, we would like to confirm whether any of them could indirectly trigger an update to the SAP internal table TTREELOADS.

We are currently investigating an unexpected update observed on TTREELOADS, with the following statement recorded:UPDATE TTREELOADS
SET GEN_DATE = ..., GEN_TIME = ..., GEN_FLAG = ...
WHERE TREE_ID = ...

To isolate the root cause, we are analyzing whether any RFC calls might lead to such an update as part of internal processing .

Our assumption is that these RFCs do not perform write operations. However, we would like to check with the community:

Has anyone experienced scenarios where any of these RFCs caused internal updates (for example, triggering a TTREELOADS update), even though no explicit database write operation is documented or visible?

Any insights, SAP Notes, or clarification on internal behavior would be greatly appreciated.

Thank you!

SAP Community - SAP Java Connector (JCo)

SAP JCo initializer error

Listener error in RFC TCP/IP

No RFC authorization for function module RFCPING.

Error message in the external connector Jco with SAP

JAVA Connector 3.1

Hi there, I have a challenge while integrating SAP JCo (3.1.10) into a Maven. Naming not allowed

I can not create a settlement rule for some service order with Java Connector

Cannot find BAPI in Action.

Query on j2ee_admin user id change in SAP SOLMAN 7.2 after system copy

Communicate from SAP Public Cloud to Java Application (Jco Server) via WebSocketRFC Problem

Outbound communication from SAP Public cloud to a Websocket RFC Server in a fenced customer network

SAP JCO 3.1.11 > Last Java supported version ?

Does SAP JCo hold memory if all heavy logic is in ABAP and Java just waits for the result?

Error rfc in cloud foundry with jco: There is no SAP Cloud Connector (SCC) connected

How to use JCO3 in MII with SSO

JCo Parameters

如何实时监控(Hana某表的)删除事件 How to runtime-subscribe to deletion events for a ERP​ table

Download the SAP Java Connector (JCo) as a guest

JCo RFC Output: Is Sorting or TOP N Selection Possible?

Can any RFCs trigger UPDATE operations?

如何实时监控(Hana某表的)删除事件 How to runtime-subscribe to deletion events for a ERP table