When invoking a jar file locally (and passing in a property) I use:
java -jar j.jar --A=B
however, another user on a different system uses:
java -jar j.jar -PA=B
Note the -P. I don't know much about the other system but this does not work for me and I can't seem to find any docs that explain how this -P flag works. Anyone seen a reference to this anywhere?
Note the property is read in the application using Springs Environment.getProperty("A") method
Related
I'm trying to run Spring Boot executable-jar built using spring-boot-maven-plugin on a Linux machine. The machine has multiple jdks installed, the one on PATH is jdk8 and changing it is unfortunately not an option. My executable-jar however needs jdk17, so when I just launch it as is I get UnsupportedClassVersionError.
I was following the official documentation and created the corresponding .conf file to override JAVA_HOME. But this does not seem to solve the issue:
[root#ios-maket updater-new]# ls
updater-new-3.0-SNAPSHOT.conf updater-new-3.0-SNAPSHOT.jar
[root#ios-maket updater-new]# cat updater-new-3.0-SNAPSHOT.conf
JAVA_HOME=/opt/jdk-17/bin/java
[root#ios-maket updater-new]# ./updater-new-3.0-SNAPSHOT.jar
Application is running as root (UID 0). This is considered insecure.
Exception in thread "main" java.lang.UnsupportedClassVersionError...
On the other hand if I run it manually everything works fine:
[root#ios-maket updater-new]# /opt/jdk-17/bin/java -jar ./updater-new-3.0-SNAPSHOT.jar
[main] INFO com.icl.ios.fias.updaternew.UpdaterNew - Starting UpdaterNew using Java 17.0.6
What am I doing wrong?
Setting JAVA_HOME is not enough, you also need to set PATH to point to JAVA_HOME/bin.
JAVA_HOME=/opt/jdk-17
PATH=${JAVA_HOME}/bin:$PATH
java -jar updater-new-3.0-SNAPSHOT.jar
Try running the jar with -Dloader.path to specify the config manually.
java -Dloader.path=./updater-new-3.0-SNAPSHOT.conf -jar ./updater-new-3.0-SNAPSHOT.jar
If this still does not work, then probably there is an issue with your config file, but from what I can see, your config file looks okay, unless the java path is incorrect.
Currently, I am trying to pass a system property to an executable in the following format: ./executable -Dvar="value" other parameters, since this is what I've seen people do for java files. I keep getting an error in the executable saying that -Dvar="value" doesn't exist as a parameter. Where am I going wrong? Are system properties exclusive to Java or something?
The -D parameter sets a system property. The system properties can be accessed through System.getProperty("<your parametername>");
A tutorial is given here https://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html
The -D is consumed by the java runtime (java.exe) and will be invisible to your application on the commandline.
I have a program which allows me to define the java executable (/usr/bin/java), but does not allow me to add specific arguments to the executable.
I want to be able to run Java with a specific argument each time in order to enable Security Manager.
So far, I have tried to add the argument after /usr/bin/java, so it looks like
java=/usr/bin/java -Djava.security.manager -Djava.security.policy=/home/java.policy
That did not work as the program probably checks to see if a file exists. Another way I tried was to make a bash script called java which contained:
/usr/bin/java -Djava.security.manager -Djava.security.policy=/home/java.policy $*
I then set the java path to /home/java (Location of my script). That however did not work either. Is there some sort of way I can do this?
Thanks.
Put your java call in a shell script java.sh:
#!/bin/bash
/usr/bin/java -Djava.security.manager -Djava.security.policy=/home/java.policy $#
Change permissions with chmod u+x java.sh, then call your program with java=./java.sh (adapt path for your script as needed).
Notes about executable bit and shebang line
Both the shebang line (#!/bin/bash) and execute permission are important here. Without them, system calls of the exec* family will fail because the kernel does not know what to do with the file or because execution is rejected due to the missing executable bit.
This is different when run directly from a shell (./java.sh), because most shells have some compatibility feature for that case so they will run a script in a shell if exec* fails. The execute permission must be set though.
The only case where neither is needed is if you give your script as argument to the shell: bash java.sh.
Your second approach would be ok, but your problem is likely to be that your Multicraft application is not finding your script. More so, it's the environment of your web server (Apache?) that may need to have PATH altered to be able to find your java wrapper script.
I am currently writing my master thesis and want to use this unofficial google api to automatically download some search queries.
https://github.com/elibus/j-google-trends-client/blob/master/README.md
I am very new to this stuff, so I would need some help to specify some inputs to get the data I need.
I have a list of queries in the same folder as the .jar which I want to use as imput for the API. But I fail to tell the program to use this folder as I do not know the proper command.
The creator of this API told me that the following would work on Linux (I use windows 8.1 (unfortunately)) but I could not transfer it to comands appropriate for my system.
for i in cat query_list.txt;do java -jar
java -jar j-google-trends-client.jar -u user -p pass -q "$i";done
More specifaclly, i got the msg that "i was unexpeted in that place". Does someone know that have to do?
Help would be much appreciated!
Thanks a lot and best regards
Micha
Those linux programs don't exist in Windows. Perhaps the following works (Java has to be in your path variable):
for /F "tokens=*" %A in (query_list.txt) do java -jar j-google-trends-client.jar -u user -p pass -q %A
I used How to do multiple things to each file in a directory with a batch script for this.
I have to get some kinks out of a shell script for work, and one of the line looks like this:
-cp: this is the classpath
This is the set of classes that are used when running a specific class.
In your example; OrganT.Tune.Mix OrganT must be a class in the classpath (in this case, inside the OrganT.jar
Read the documentation, can be found here
Just a hint - under linux and mac you can use the
man <command goes here>
comman in the terminal/shell to display all parameters and usage information available for the specific command.
-cp stands for classpath. The CLASSPATH variable is one way to tell applications, including the JDK tools, where to look for user classes.
java -classpath .;YourJarFile.jar
I think you want to run a script for including the class path and execute the jar.
To do this in any text editor type java -jar YourJarFile.jar and save it, with extention (anyName.sh) assuming you have got linux flavour. Make it executable using the command chmod 775 anyName.sh
For windows type java -jar YourJarFile.jar, and save it with extention (anyName.bat)