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Otto, The following are some links that I've found helpful when building RPG/JNI apps. Some actually have "C" examples that mirror some of what you are attempting to accomplish. Search the pages looking for your respective JNI function. As for your code, at first glance it looks OK. Obvioulsy the truth will manifest itself at compile and run time. BTW: Verses calling another application/component to handle literal conversion, I chose to construct RPG copy source that contains the respective ASCII representations, method, fields and java signatures. This, in my environment at least, has become an effective repository for reuse. The following is a code snippet from source member "signatures" in source file JavaIO (for java.io...): ************************************************************ * Define ASCII strings used by JNI. ************************************************************ * 'Ljava/io/PrintStream;' signature DJINPS C x'4c6a6176612f696f2f- D 5072696e7453747265616d3b' * 'java/io/PrintStream' DJavaIOPS C x'6a6176612f696f2f- D 5072696e7453747265616d' * 'java/io/Writer' DJavaIOWtr C x'6a6176612f696f2f- D 577269746572' * 'Ljava/io/Writer;' signature DJIOWtr C x'4c6a6176612f696f2f- D 5772697465723b' * 'java/io/PrintWriter' DJavaIOPW C x'6a6176612f696f2f- D 5072696e74577269746572' * 'Ljava/io/PrintWriter;' signature DJINPW C x'4c6a6176612f696f2f- D 5072696e745772697465723b' * 'out' Dout C x'6f7574' * 'println' Dprtln C x'7072696e746c6e' Good luck, Michael Rooney Citigroup International This link demonstrates JNI calls for FindClass, GetObjectClass, newStringUTF and GetStringUTFChars: http://java.sun.com/docs/books/jni/html/fldmeth.html This link demonstrates JNI calls for CallObjectMethod, GetMethodId, newStringUTF and GetStringUTFChars: http://forum.java.sun.com/thread.jsp?forum=52&thread=491990&tstart=120&trange=15 This link dicusses pasing string and array data between java and other programming languages: http://java.sun.com/developer/onlineTraining/Programming/JDCBook/jnistring.html -----Original Message----- From: rpg400-l-bounces+michael.p.rooney=citigroup.com@xxxxxxxxxxxx [mailto:rpg400-l-bounces+michael.p.rooney=citigroup.com@xxxxxxxxxxxx]On Behalf Of Steffan, Otto (GE Consumer Finance) Sent: Tuesday, April 13, 2004 9:51 AM To: 'RPG programming on the AS400 / iSeries' Subject: RE: Java array in ILE RPG Hello, I have to agree that really the JNI solution "is not the easiest soluton" as Michael stated in his prior mail. I am going to call a CallObjectMethodA JNI method and finding that the job is much more complex than I anticipated before :-(. Please can someone check my following lines to assure me that I am on the right track? we have V5R2 My sequence of logical deductions (=>): 1. JNI member contains the prototype for CallObjectMethodA JNI method: D CallObjectMethodA... D PR LIKE(jobject) D EXTPROC(*CWIDEN D : JNINativeInterface. D CallObjectMethodA_P) D env LIKE(JNIEnv_P) VALUE D obj LIKE(jobject) VALUE D methodID LIKE(jmethodID) VALUE D args LIKE(jvalue) DIM(1) => I have to pass methodID of the java-array method. 2. I get methodID using another JNI method GetMethodID that is prototyped like this: D GetMethodID PR LIKE(jmethodID) D EXTPROC(*CWIDEN D : JNINativeInterface. D GetMethodID_P) D env LIKE(JNIEnv_P) VALUE D clazz LIKE(jclass) VALUE D name * OPTIONS(*STRING) VALUE D sig * OPTIONS(*STRING) VALUE => I have to pass also: jclass object, name of java-array method, signature of java-array method. name & signature must be in UTF-8 according to GetMethodID spec at http://java.sun.com/j2se/1.3/docs/guide/jni/spec/functions.doc.html#16660 => I must know how to get a class object from a class. => I must know how to convert EBCDIC to UTF-8. 3. I get the class object using GetObjectClass JNI method. 4. I can convert RPG literals for java-array method name & signature using ldap_xlate_local_to_utf8() API. (I found an example from Scott Klement at iseriesnetwork RPG forum.) Thanks for reading up to this point. Otto Steffan -----Original Message----- From: Rooney, Michael P [mailto:michael.p.rooney@xxxxxxxxxxxxx] Sent: Monday, April 12, 2004 4:37 PM To: RPG programming on the AS400 / iSeries Subject: RE: Java array in ILE RPG Jon, You haven't missed a thing. As I stated in one of my previous posts, using the JNI via RPG to process a Java Array Object involves more code than Barbara's solution. Clearly there are (always) serveral ways to accomplish an objective. Thus, sometimes the more significant challenge for us technologists is using the solution best suited for the problem at hand (verses the one that stimulates the techie in each of us). While I have contributed to this post, I can not definitively say which of these options I would use as each of the 3 have merit. Without hesitation, though, a JNI solution presents the most complexity. It may be "cool" but it is not the easiest soluton. Regards, Michael Rooney Citigroup International _______________________________________________ This is the RPG programming on the AS400 / iSeries (RPG400-L) mailing list To post a message email: RPG400-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/rpg400-l or email: RPG400-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/rpg400-l.
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