We Keep Coding

Cannot open sever.jar file

So I was trying to make a 1.17.1 minecraft server on my mac. I couldn't open my 1.17.1_server.jar with Java 8 so I download Java 16.0.2.
Unfortunately, everytime I was opening the 1.17.1_server.jar file, I got
"The Java JAR file "1.17._server.jar" could not be launched." .
I first thought that it was because the file was launch by Java 8 instead of 16.
So I went into the terminal and run :<path to java> -jar 1.17.1_server.jar
I then got this : Error: Unable to access jarfile 1.17.1_server.jar
Finally i tried to put the path of the jar file in the command...
So I've run : path to java -jar path to server
and got this :
[main/ERROR]: Failed to load properties from file: server.properties
[15:57:35] [main/WARN]: Failed to load eula.txt
[15:57:35] [main/INFO]: You need to agree to the EULA in order to run the server. Go to eula.txt for more info.
So why I have to agreed Eula if i've never launched it ? Does it think that he already been launched ?

As stated in the error message
[15:57:35] [main/INFO]: You need to agree to the EULA in order to run the server. Go to eula.txt for more info.
You have to open the file and check yes

Okay find the solution: my eula and server properties file were in my user folder dk why (never moved them so...)

jna Native.LoadLibrary does not manage to load library on server (working in local)

I use JNA to load a c++ library (.so) in a java project. I package my library inside the jar, and load it from the jar when instantiating the java class that uses it. I do all this like so:
mvn install compiles the c++ code and packages the outcome dynamic library inside the jar.
I call in a static context when instantiating the LibraryWrapperClass the following
System.load( temp.getAbsolutePath() );
where temp is a temporary file containing the library which was found in the jar. This code is based on the work found here adamheinrich
- I call Native.loadLibrary(LIBRARYPATH) to wrap the library into a java class.
private interface Wrapper extends Library {
Wrapper INSTANCE = Native.loadLibrary( C_LIBRARY_PATH, Wrapper.class );
Pointer Constructor();
...
}
I run tests and validate that the library was found and up and running.
I use a java web project that depends on this project. It uses tomcat and runs fine in local.
My issue is that when I deploy on the server, the LibraryWrapperClass cannot instantiate. Error on server is:
java.lang.NoClassDefFoundError: Could not initialize class pacakgeName.LibraryWrapperClass
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:375)
at org.hibernate.annotations.common.util.StandardClassLoaderDelegateImpl.classForName(StandardClassLoaderDelegateImpl.java:57)
at org.hibernate.boot.internal.MetadataBuilderImpl$MetadataBuildingOptionsImpl$4.classForName(MetadataBuilderImpl.java:758)
at org.hibernate.annotations.common.reflection.java.JavaReflectionManager.classForName(JavaReflectionManager.java:144)
at...
This error seems that the library is found, since there is not the UnsatisfiedLinkError exception thrown. But something else is failing. Do someone know what could happen? How could I debug?
I recall that everything works perfectly in local.

How could I debug?
1. with strace
strace will give you what files Tomcat is trying to open : strace -f -e trace=file -o log.txt bin/startup.sh
After this, look for packageName in log.txt, or other files not found with :
egrep ' open.*No such file' log.txt
2. with JConsole
Enable JMX, launch a JConsole, go to VM summary tab, and check/compare very carefully VM arguments/classpath/library path/boot class path
3. dependency listing with ldd
If a dependency issue is likely to be the problem, the ldd sharedLibraryFile.so command lists all the dependencies and allows to track which one might be missing.

Creating a directory on client machine using applet

I have a self signed applet running in the browser, this applet should create a directory on the client machine using this code.
boolean success = (new File("myDir")).mkdirs();
if (!success) {
System.err.println("Directory creation failed");
}
However, when I run it in the browser (under Apache) and after accepting all the security warnings I can't find myDir directory on my machine.
Am I doing something wrong?

I guess you are not looking at the right place...
Given your code snippet, this directory will be created in the current working directory. To be sure where that is on your machine just try to see what the following code gives out :
System.out.println(System.getProperty("user.dir"));

You're not giving it an absolute path so it's creating myDir in the working directory that the browser runs it in, probably a temp dir, or even a "sandbox" area in some browsers.

Because you run applet in sandbox, so You cannot access into user machine resource.
Please see document:
Applet security

TCLBLEND FAILURE - Centos 6.4

I have been trying to use a home grown test tool and after doing an update to Centos 6.4, I am no longer able to run the tcl based tool. I am getting the following error and I have no internet access on this server. Kindly advise how do I solve this problem?
Thanks
"XpUtils::iload -d /usr/local/testtool/repo/package/linux-glibc2.3-x86_64/lib/tcljava1.4.1 tclblend" failed:
couldn't load file "/usr/local/testtool/repo/package/linux-glibc2.3-x86_64/lib/tcljava1.4.1/libtclblend.so": libjava.so: cannot open shared object file: No such file or directory
while executing
"error "\"XpUtils::iload -d $dir tclblend\" failed:\n $errMsg""
(procedure "loadtclblend" line 168)
invoked from within
"loadtclblend /usr/local/testtool/repo/package/linux-glibc2.3-x86_64/lib/tcljava1.4.1"
("package ifneeded java 1.4.1" script)
invoked from within
"package require java"
("eval" body line 1)
invoked from within
"eval package require $pkg"
("foreach" body line 2)
invoked from within
"foreach pkg $pkgList {
set ::${pkg}Version [eval package require $pkg]
}"
(file "/usr/local/testtool/testtool" line 165)

If you read the error message trace, you'll see that it says that this is all caused by:
libjava.so: cannot open shared object file: No such file or directory
The first steps would then be to ensure that you've got a version of Java actually installed, to check that it includes the file libjava.so, and that the file has been indexed by the system shared library catalog.
It might also be worth checking that all its dependencies are also present and that you've got the architecture for the Tcl library and the Java library matched (e.g., both 32-bit) as those can cause odd failures when they go wrong.

Using Java Within PHP - Class Not Found

I'm using Tomcat and PHP5 with JavaBridge. I have bridged PHP and Java so I can screencap web pages within PHP. This was working on another server but after moving to a new server I can not get it working, so I'm reaching for straws here.
require_once("http://localhost:8080/JavaBridge/java/Java.inc");
java_autoload("/web/sites/madfrog/domain.com/cron/bin/html2image.jar");
$JavaHTML2Image = new Java("com.elance.proposal.html2image.client.MainBridge");
It should have loaded all of the project html2image.jar when the script _autoloaded it, however when you create the new Java object I get the error
Class Not Found: Fatal error: Uncaught [[o:Exception]:"java.lang.Exception: CreateInstance failed: new com.elance.proposal.html2image.client.MainBridge. Cause: java.lang.ClassNotFoundException: com.elance.proposal.html2image.client.MainBridge
I asked the guys over in Java and they said I needed to put the jar file in the lib so Java could find it, so I dumped it into Tomcat's webapps folder an into /usr/share/java. But that did nothing. With that said the PHP has a direct reference to it, so it should be loaded.
I'm at a lost after two days. any help is appreciated!

Which version of Tomcat do you use?
For Tomcat 6 or Tomcat 7 put the jar either in ${tomcat.home}/lib or in ${tomcat.home}/webapps/${your.war}/lib
While tomcat.home is your tomcat installation directory. And your.war is the name of your war file.