SQL Error [42724]: Java stored procedure or user-defined function "DB2INST1.GETLENGTH", specific name "SQL190522092641080" could not call Java method "getlength", signature "()I".. SQLCODE=-4306, SQLSTATE=42724, DRIVER=4.25.13

import COM.ibm.db2.app.*;
public class JLOB extends UDF {
  public void getlength( int len) throws Exception {
   set( 1, (int) 42);
  }
}

create OR replace function getlength()
RETURNS int
LANGUAGE java
EXTERNAL NAME 'JLOB!getlength'
FENCED THREADSAFE
NO SQL
NOT NULL CALL
DETERMINISTIC
NO EXTERNAL ACTION
DISALLOW PARALLEL
PARAMETER STYLE java;

A LOB object is also materialized when an application program performs any of the following actions, regardless of the progressiveStreaming or streamBufferSize settings:

PARAMETER STYLE JAVA

//       ------  JLOB.class ----------
//import java.sql.*;
import COM.ibm.db2.app.*;

public class JLOB extends UDF
{
        public void getlength(COM.ibm.db2.app.Clob clob, long len) throws Exception
        {
        if ( null == clob) {
        set(2, 0);
        return;
        }
        long res = clob.size();
        set( 2, res );
        }

}

-- on DB2

drop function getlength;
CALL SQLJ.REFRESH_CLASSES();

create OR replace function getlength(c1 CLOB(300M))
RETURNS bigint
LANGUAGE java
EXTERNAL NAME 'JLOB!getlength'
NO EXTERNAL ACTION
DETERMINISTIC
FENCED THREADSAFE
RETURNS NULL ON NULL INPUT
PARAMETER STYLE DB2GENERAL
NO SQL
SCRATCHPAD 10
FINAL CALL
DISALLOW PARALLEL
NO DBINFO

-- SELECT getlength(clob('sdjfbsdfbgkjsdh')) FROM SYSIBM.SYSDUMMY1