AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Mac driving me crazy Goto page 1, 2  Next          AppletTalk.com Forum Index -> Java Help View previous topic :: View next topic   Author Message Redbeard Guest Posted: Sat Sep 16, 2006 1:01 am    Post subject: Mac driving me crazy I wrote an applet that I need to be able to run on an older iMac which has Java 1.3.1 installed. Just to be safe, I compiled it to 1.2 specs (-source 1.2 -target 1.2). It runs fine on my Windows box, it runs fine on my brothers newer Mac (Java v1.4 - I think). But I keep getting a noSuchMethodError error on the old iMac. The trace stack only shows three items: - a call to line 19 of the init method of my applet - a call to sun.applet.AppletPanel.run() - a call to java.lang.Thread.run() Line 19 contains a call to an instance method for an object whose class I also wrote. If I'm reading the stack correctly, that is the method that the JRE cannot find - not some method that would be part of any Java Foundation Classes. So differences in Java versions cannot explain why the method cannot be found. If it really isn't there, the applet shouldnt work for any version, but it does, so the method IS there. Any ideas what kind of glitch I am running into? I'm out of ideas. Here is the URL if you want to see it for yourself. http://www.district87.org/staff/cowderyt/JavbotDemo/JavbotDemo.htm Thanks in advance. Back to top Daniel Dyer Guest Posted: Sat Sep 16, 2006 1:17 am    Post subject: Re: Mac driving me crazy On Fri, 15 Sep 2006 21:01:46 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com> wrote: Quote: I wrote an applet that I need to be able to run on an older iMac which has Java 1.3.1 installed. Just to be safe, I compiled it to 1.2 specs (-source 1.2 -target 1.2). It runs fine on my Windows box, it runs fine on my brothers newer Mac (Java v1.4 - I think). But I keep getting a noSuchMethodError error on the old iMac. Have a look at the -bootclasspath option of the javac compiler. Although you are using the correct source and target options, you are still compiling against the newer libraries. You really need to get hold of the 1.3.1 libraries and reference these with -bootclasspath so that you can catch these kind of problems at compile-time, rather than (less reliably) at runtime. The other way of doing this is to build it on the old iMac (assuming it has the JDK and not just the JRE). Quote: The trace stack only shows three items: - a call to line 19 of the init method of my applet - a call to sun.applet.AppletPanel.run() - a call to java.lang.Thread.run() Can you post the actual stack trace and the actual code of your init method? Quote: Here is the URL if you want to see it for yourself. http://www.district87.org/staff/cowderyt/JavbotDemo/JavbotDemo.htm Works on my Mac, but thats using Java 5.0. Dan. -- Daniel Dyer http://www.dandyer.co.uk Back to top Oliver Wong Guest Posted: Sat Sep 16, 2006 1:18 am    Post subject: Re: Mac driving me crazy "Redbeard" <tom.cowdery (AT) bigfoot (DOT) com> wrote in message news:1158350506.477976.234050 (AT) b28g2000cwb (DOT) googlegroups.com... Quote: I wrote an applet that I need to be able to run on an older iMac which has Java 1.3.1 installed. Just to be safe, I compiled it to 1.2 specs (-source 1.2 -target 1.2). It runs fine on my Windows box, it runs fine on my brothers newer Mac (Java v1.4 - I think). But I keep getting a noSuchMethodError error on the old iMac. The trace stack only shows three items: - a call to line 19 of the init method of my applet - a call to sun.applet.AppletPanel.run() - a call to java.lang.Thread.run() Line 19 contains a call to an instance method for an object whose class I also wrote. If I'm reading the stack correctly, that is the method that the JRE cannot find - not some method that would be part of any Java Foundation Classes. So differences in Java versions cannot explain why the method cannot be found. If it really isn't there, the applet shouldnt work for any version, but it does, so the method IS there. Can you post the stacktrace, and your init method, marking which line is line 19? - Oliver Back to top Andrew Thompson Guest Posted: Sat Sep 16, 2006 2:17 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 21:01:46 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: I wrote an applet that I need to be able to run on an older iMac which has Java 1.3.1 installed. Just to be safe, I compiled it to 1.2 specs (-source 1.2 -target 1.2). It runs fine on my Windows box, it runs fine on my brothers newer Mac (Java v1.4 - I think). But I keep getting a noSuchMethodError error on the old iMac. Have a look at the -bootclasspath option of the javac compiler. (remainder snipped) Yes. The -bootclasspath option is *vital* for reliable use of code on older VM's, -source/-target are simply not enough. Andrew T. Back to top Redbeard Guest Posted: Sat Sep 16, 2006 2:55 am    Post subject: Re: Mac driving me crazy Oliver Wong wrote: Quote: Can you post the stacktrace, and your init method, marking which line is line 19? - Oliver The iMac is at work, and I am at home. So, no I can't do list the stacktrace until Monday. Nor do I have the source code here with me, but without the stacktrace, the init method won't do much good. I do recall what line 19 says: world.addBaskets(); World is the content pane of the JApplet. It is an instance of what I call the "JavbotWorld" class. If you have been to the URL, you see little numbers at various places. Those represent "baskets" that the robots can pick up. The number is the quantity at that intersection. The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. I did try to compile on the old iMac, but for some reason the same compile commands that I used in Windows did nothing on the iMac. That makes me wonder if there is something wrong with the Java installation on the machine. But I don't have another iMac (of that vintage) to test it against. Sadly, my room has no windows, so seeing how far the iMac will fly is also out of the question. ;^) Back to top Redbeard Guest Posted: Sat Sep 16, 2006 2:58 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 21:01:46 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: I wrote an applet that I need to be able to run on an older iMac which has Java 1.3.1 installed. Just to be safe, I compiled it to 1.2 specs (-source 1.2 -target 1.2). It runs fine on my Windows box, it runs fine on my brothers newer Mac (Java v1.4 - I think). But I keep getting a noSuchMethodError error on the old iMac. Have a look at the -bootclasspath option of the javac compiler. Although you are using the correct source and target options, you are still compiling against the newer libraries. You really need to get hold of the 1.3.1 libraries and reference these with -bootclasspath so that you can catch these kind of problems at compile-time, rather than (less reliably) at runtime. The other way of doing this is to build it on the old iMac (assuming it has the JDK and not just the JRE). The trace stack only shows three items: - a call to line 19 of the init method of my applet - a call to sun.applet.AppletPanel.run() - a call to java.lang.Thread.run() Can you post the actual stack trace and the actual code of your init method? Here is the URL if you want to see it for yourself. http://www.district87.org/staff/cowderyt/JavbotDemo/JavbotDemo.htm Works on my Mac, but thats using Java 5.0. Dan. -- Daniel Dyer http://www.dandyer.co.uk Just so I don't misunderstand you. You're saying I should install 1.3.1 on my machine and use -bootclasspath to use it to compile? Back to top Daniel Dyer Guest Posted: Sat Sep 16, 2006 3:17 am    Post subject: Re: Mac driving me crazy On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com> wrote: Quote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The Microsoft JVM is roughly compatible with Java 1.1, which means no Random.nextInt(int n), which was introduced in Java 1.2. Dan. -- Daniel Dyer http://www.dandyer.co.uk Back to top Daniel Dyer Guest Posted: Sat Sep 16, 2006 3:26 am    Post subject: Re: Mac driving me crazy On Fri, 15 Sep 2006 22:58:16 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com> wrote: Quote: Just so I don't misunderstand you. You're saying I should install 1.3.1 on my machine and use -bootclasspath to use it to compile? Not necessarily. You do need to obtain the jar file (rt.jar or classes.jar) that contains the core classes from that version and point to that file with -bootclasspath. Dan. -- Daniel Dyer http://www.dandyer.co.uk Back to top Andrew Thompson Guest Posted: Sat Sep 16, 2006 3:34 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The MS JVM was never installed in any browser for the Mac., not even the Mac. version of IE. It is the "bootclasspath gotcha'" - I'll bet my bottom dollar on it. Andrew T. Back to top Daniel Dyer Guest Posted: Sat Sep 16, 2006 3:43 am    Post subject: Re: Mac driving me crazy On Fri, 15 Sep 2006 23:34:07 +0100, Andrew Thompson <andrewthommo (AT) gmail (DOT) com> wrote: Quote: Daniel Dyer wrote: On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The MS JVM was never installed in any browser for the Mac., not even the Mac. version of IE. I wasn't sure about that, so I searched before posting. This link (http://support.microsoft.com/kb/180970/) seems to suggest that it was shipped at some point. Dan. -- Daniel Dyer http://www.dandyer.co.uk Back to top Andrew Thompson Guest Posted: Sat Sep 16, 2006 4:02 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 23:34:07 +0100, Andrew Thompson .... The MS JVM was never installed in any browser for the Mac., not even the Mac. version of IE. I wasn't sure about that, so I searched before posting. This link (http://support.microsoft.com/kb/180970/) seems to suggest that it was shipped at some point. Huhh! I stand corrected. [ Maybe Sun should have sued 'em, just that little bit more.. ] Andrew T. Back to top Redbeard Guest Posted: Sat Sep 16, 2006 4:19 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The Microsoft JVM is roughly compatible with Java 1.1, which means no Random.nextInt(int n), which was introduced in Java 1.2. I considered that as a possibility. In addition to IE, I've tried the applet in Mozilla and Safari, neither of which would have the MS JVM. Same result. So I'm reasonably certain that the MS JVM is not the culprit. Back to top Redbeard Guest Posted: Sat Sep 16, 2006 4:27 am    Post subject: Re: Mac driving me crazy Daniel Dyer wrote: Quote: On Fri, 15 Sep 2006 22:58:16 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: Just so I don't misunderstand you. You're saying I should install 1.3.1 on my machine and use -bootclasspath to use it to compile? Not necessarily. You do need to obtain the jar file (rt.jar or classes.jar) that contains the core classes from that version and point to that file with -bootclasspath. OK. I'm not sure how I'll get those without just installing 1.3.1, but either is doable. FWIW, much of this code was originally written in 1.3.1, and used to run on this iMac just fine. I made some revisions over the summer, and that is when it quit working on the iMac. Andrew Thompson wrote: Quote: It is the "bootclasspath gotcha'" - I'll bet my bottom dollar on it. I think you are right. I also ran into a problem with another file that I thought I'd compiled to 1.2 specs. Somehow Color.WHITE got through the compiler, even though I had use -source 1.2 and -target 1.2. Of course, the capitalized versions of the color constants didn't show up until 1.4. Looks like I need to find an old version of rt.jar or classes.jar. Might be able to steal one or the other off of the iMac! Back to top Steve W. Jackson Guest Posted: Mon Sep 18, 2006 10:13 pm    Post subject: Re: Mac driving me crazy In article <1158359647.739342.145880 (AT) k70g2000cwa (DOT) googlegroups.com>, "Andrew Thompson" <andrewthommo (AT) gmail (DOT) com> wrote: Quote: Daniel Dyer wrote: On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The MS JVM was never installed in any browser for the Mac., not even the Mac. version of IE. It is the "bootclasspath gotcha'" - I'll bet my bottom dollar on it. Andrew T. And you might very well lose that bet. You have to know what version of Mac OS X is in use before you can know whether Java 1.3.1 is even available for the machine in question. The latest machines that came with 10.4 installed -- Steve W. Jackson Montgomery, Alabama Back to top Redbeard Guest Posted: Tue Sep 19, 2006 7:10 am    Post subject: Re: Mac driving me crazy Steve W. Jackson wrote: Quote: In article <1158359647.739342.145880 (AT) k70g2000cwa (DOT) googlegroups.com>, "Andrew Thompson" <andrewthommo (AT) gmail (DOT) com> wrote: Daniel Dyer wrote: On Fri, 15 Sep 2006 22:55:26 +0100, Redbeard <tom.cowdery (AT) bigfoot (DOT) com wrote: The method called on line 19 simply places a random number of baskets at a random place in the JavbotWorld. It clearly works on newer versions of Java, so the method exists. And the only thing in the addBaskets() method that involves a JFC is a couple of calls to the nextInt(int n) method of the Random class. And that doesn't show up in the stacktrace anyway. OK, this is where you need to be absolutely certain which Java Runtime you are using. Which browser are you using? Is it Internet Explorer for the Mac? And if so, are you sure it is not using a Microsoft JVM? The MS JVM was never installed in any browser for the Mac., not even the Mac. version of IE. It is the "bootclasspath gotcha'" - I'll bet my bottom dollar on it. Andrew T. And you might very well lose that bet. You have to know what version of Mac OS X is in use before you can know whether Java 1.3.1 is even available for the machine in question. The latest machines that came with 10.4 installed -- Steve W. Jackson Montgomery, Alabama I stated that the iMac was an older one with v1.3.1 installed. However, that begs another question. Can I upgrade Java on an iMac? I'm very Windows-centric, so I'm not up on versions of OS X. But I do know this iMac cannot run the newest version of OS X, which is apparently the only version that can run Java 5. But if I could upgrade it to 1.4, that would be an improvement. It is one of the blue, all-in-one iMac's and is at least 3 years old, and probably older. However, the OS has been upgraded once (that I know of). I believe the upgrade was called Jaguar. It is whichever version came BEFORE Safari. I added Safari. Can Java be upgraded on such a machine? 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