I am writing a Java applet and embedding it in a web page.
It used to run Mac and Windows in different browsers without problem.
I was using NetBeans on the Mac to build the .jar file the applet used.
For some reason or another I decided to load the project on the Windows' NetBeans - I started getting the following error on the Windows machine when accessing the web page from any browser:
java.lang.ClassFormatError: Incompatible magic value 1008813135 in class file
Fearing that it must have been my decision to open the project on Windows that caused this error - I tried to build from the Mac's NetBeans - but the error persisted.
I started a while new project on the Mac and imported the existing source code: still same problem.
I was doing some reading about this error and it seems that the magic number expected is 0xCAFEBABE in hex which is 3405691582 in decimal, not 1008813135. So it looks like the Mac version of Java doesn't produce this file header any more? Hoe can that be? I didn't do any updates or anything.
Yes, 0xCAFEBABE is the usual first 4 bytes of a Java file.
1008813135 is <!DO in Latin encoding, which is, in all probability, the start of <!DOCTYPE....
It is therefore likely the start of a 404 error, or some other error page.
I have not experienced this problem, but Googling this error yields several possible solutions:
forum.sun.com - Java Applet Development - Incompatible magic value 1008813135 in class file MyApplet
Thanks God the problem is solved.
Its the Java cache, so the solution go to Java Control Panel, "General" tab, and under "Temporary Internet Files" click "Settings", then click "Delete Files". Try using the applet again.
"Incompatible magic value 1008813135" Error?
The problem is now solved: I found out that the website host I was using didn't support .jar files at all. I mass-uploaded the files with my ftp program and didn't notice that it ignored the .jar files completely.
Errors on java initialization
Alright, so it was an apache configuration issue, removed this line from my httpd.conf file:
# DefaultType application/x-httpd-php
Fixed the issue.
If you are using Spring security or some sort of custom Servlet Filters, make sure, that the archive or codebase location is in "permitAll" access. This was to problem in my case
I was facing the same problem.The reason in my case was all dependency library that Applet uses was not signed and also applet not able to locate them.
So i Have added all the dependent library along with main applet in jsp file like below :
app.archive = '/esense/resources/lib/Applet.jar, /esense/resources/lib/jasypt-1.7.jar, /esense/resources/lib/mysql-connector-java-5.1.30.jar, /esense/resources/lib/runtime-api-1.0.jar';
I have also signed all the jar.
Hope this may work in your case.
The incompatible magic number is the first four bytes of a html file that has some error message in it, probably a message that the file isn't found.
I encountered this phenomenon when I didn't take case sensitivity into account in the codebase element of the applet tag. Things worked well on Windows, but the internet server I was using was running UNIX where filename case sensitivity is important. Making the case of all file and directory names in the code and codebase elements solved the problem.
I just clicked on maven->update project->include snapshot release in my spring boot and it worked.
Related
I really don't know what the problem is.
I followed several web postings about installing and settings of JDK/ JRE and also completed clearly on environment variables :Path & CLASS PATH
I'm sure about that since i checked the cmd and it worked well.
the same problem occured over and over again.
I corrected on Library tab
I add the Library list like this,
But, I still have the same problem. Did I make a severe mistake? what should I do about this problem?
still have JAVA problems
Please check the Java source directory configuration under Java Build Path, Source tab and Java Compiler version settings.
Did you recently update your Java version? If so, then you have to readjust your path so that it directs to the new updated version.
I have some problems with opening a SAN switch in Webtools (Java version 8 Update 31).
The first problem was a failed to validate certificate
This was fixed by following the instructions on this site
However, then I got following error:
Which was solved by adding these 3 entries to the site to the exception site list (the last one is the only one necessary I think)
http://i.p.address/*
http://i.p.address/switchExplorer.html
http://i.p.address/
But now I get following error:
your security settings have blocked an application from running due to missing a “permissions” manifest attribute in the main jar web tools
The solution seems to be adding the URL to the exceptions but I have already done that in the previous step..
Open the "Mission Control Panel" of java.
If you cannot find it, have a look in the bin folder of your jdk installation, the executable should be called jcontrol.
Run it, open tab "Security", Button "Edit Site List" and add your URL to the Exception Site List. I.e. https://10.0.0.1 is all you need.
Use oracle java if you use linux and somehow miss jcontrol from the openjdk package.
Afterwards you should be able to start the .jnlp (or however you want to start the applet) of your desire.
I used old Eclipse (Helios) and old Tomcat (5.5) for a large web project. After updating to Tomcat 6, this code stopped working:
short foo = 3;
Integer bar = foo;
Apparently, this is invalid code according to the Java language specification[1], and there was a bug in the old Eclipse compiler so it didn't report it. New Eclipse (Kepler) reports it as an error.
I'm not quite sure why it stopped working with new Tomcat since it is using the same Java compiler as the old Tomcat, but the code is invalid and I want to fix it throughout the project.
First I tried validating the entire project in new Eclipse so it would list all .jsp files with this error. However, this validation in Eclipse doesn't seem to work very well since sometimes it detects several (existing) errors in a file and sometimes reports no errors in the same file (without changes, 10 seconds later).
Next thing I tried was to import project to NetBeans (7.4) and try to list those errors here. When I open a file with error, it detects it: "incompatible types: short cannot be converted to Integer". However, when I list all errors in the "Action Items" list, I can't find those errors (although I set the filter to include compiler errors).
I thought that listing all Java errors in all JSP files in a project would be easy, but turned out that it wasn't. How can I do it?
[1] Widening and boxing with java
The solution to this problem is to compile all JSP files in the project (i.e. generate Java files for them) and then inspect errors for generated files.
NetBeans has option to pre-compile all JSP files, but this didn't work for me because it stops after it hits first Java file with errors (maybe there is a way to circumvent this?).
Another solution might be to configure Apache Maven to build entire project, but I didn't try this, because a co-worker came up with a nice quick-n-dirty solution:
Generate a wget request for every JSP file in project and run all these requests. It doesn't matter that wget can't really access the pages since it isn't logged in, it just 'touches' them and forces the Tomcat to generate Java files.
Something like this (linux/cygwin):
find jsp -name '*.jsp' -printf 'http://localhost:8080/App/%p\n' > tmp/urls
wget -q --proxy=off --spider -i tmp/urls
i'm stucked on this point since 3 days and i'm out of idea.
If someone could help, my week will start really well !
I'm writing a java applet.
Under eclipse environement it works well.
I build the jar (with all the dependencies aggregated) and launch it on a browser (chrome, firefox, ie ...). The code below does not work anymore because it returns an empty list:
Iterator iter = ImageIO.getImageReadersByFormatName("DICOM");
It seems that the Image Readers that claim to be able to decode the DICOM format are available under eclipse environement but not under browser environement ...
I don't think it's a security exception as i have no such error (I have no exception, problem is the returned list is empty).
Thanks in advance for any clue ...
I've found the solution. A spi image reader was not found into the manifest. It was because the dependencies jar files were aggregated into my jar, leading my manifest to be overriden by another. Now I don't aggregate my jar anymore and it's ok, my manifest stay safe and the spi image reader is found.
I haven't worked with Java in about 10 years, so it's very probable I'm doing something elementary wrong here...
I am writing a "server-side extension" for SmartFoxServer (SFS). In my login script, I need to make a connection to MS SQL Server, which I am attempting to do using JDBC. I have tested the JDBC code in my debug environment, and it works fine.
BUT
When I put the server-side extension in the SFS "extensions" folder (as per spec), I'm getting a NoClassDefFoundError thrown - clearly SFS can't find the required JAR (sqljdbc4.jar). I have tried putting this JAR in my classpath; I tried including it in my Eclipse project - but for some reason, SFS adamantly refuses to accept the existence of this JAR.
What am I doing wrong?
I have no experience with the product you mention but many years of Java experience.
Have you tried putting the sqljdbc4.jar in the same location as your server-side extension (the extensions 'directory') ? You will likely have to restart SFS after this.